Vasculitides

Overview

Definition

Vasculitides are diseases of the blood vessels, with inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of vessel walls leading to bleeding, ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage, and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage of distal tissue and organs.

Classification

The following classification is adapted from the 2012 International Chapel Hill Consensus Conference Nomenclature of Vasculitides:

• Large-vessel vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus (LVV): 
  • Takayasu’s arteritis (TAK) 
  • Temporal arteritis Temporal arteritis Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis, or giant-cell arteritis ( GCA GCA Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis)
• Medium-vessel vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus (MVV):
  • Polyarteritis nodosa (PAN)
  • Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease ( KD KD An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease) or mucocutaneous lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs node syndrome 
  • Thromboangiitis obliterans Thromboangiitis Obliterans A non-atherosclerotic, inflammatory thrombotic disease that commonly involves small and medium-sized arteries or veins in the extremities. It is characterized by occlusive thrombosis and fibrosis in the vascular wall leading to digital and limb ischemia and ulcerations. Thromboangiitis obliterans is highly associated with tobacco smoking. Thromboangiitis Obliterans (Buerger’s Disease) ( TAO TAO A non-atherosclerotic, inflammatory thrombotic disease that commonly involves small and medium-sized arteries or veins in the extremities. It is characterized by occlusive thrombosis and fibrosis in the vascular wall leading to digital and limb ischemia and ulcerations. Thromboangiitis obliterans is highly associated with tobacco smoking. Thromboangiitis Obliterans (Buerger’s Disease)), or Buerger disease 
• Small-vessel vasculitis Small-Vessel Vasculitis Henoch-Schönlein Purpura (SVV):
  • Antineutrophil cytoplasmic antibody ( ANCA ANCA Group of systemic vasculitis with a strong association with anca. The disorders are characterized by necrotizing inflammation of small and medium size vessels, with little or no immune-complex deposits in vessel walls. Rapidly Progressive Glomerulonephritis)–associated vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus ( AAV AAV Antinuclear cytoplasmic antibody (ANCA)-associated vasculitis (aav) includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (mpa), and eosinophilic granulomatosis with polyangiitis (egpa). All 3 diseases cause life-threatening small-vessel vasculitis with a wide range of systemic manifestations, which can involve the lungs, kidneys, skin, and heart. Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis): 
    • Granulomatosis with polyangiitis Granulomatosis with Polyangiitis A multisystemic disease of a complex genetic background. It is characterized by inflammation of the blood vessels (vasculitis) leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies (antineutrophil cytoplasmic antibodies) against myeloblastin. Granulomatosis with Polyangiitis ( GPA GPA A multisystemic disease of a complex genetic background. It is characterized by inflammation of the blood vessels (vasculitis) leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies (antineutrophil cytoplasmic antibodies) against myeloblastin. Granulomatosis with Polyangiitis)
    • Microscopic polyangiitis (MPA)
    • Eosinophilic granulomatosis with polyangiitis Granulomatosis with Polyangiitis A multisystemic disease of a complex genetic background. It is characterized by inflammation of the blood vessels (vasculitis) leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies (antineutrophil cytoplasmic antibodies) against myeloblastin. Granulomatosis with Polyangiitis (EGPA), formerly known as Churg-Strauss syndrome
  • Immune-complex SVV:
    • Anti– glomerular basement membrane Glomerular basement membrane The layer of extracellular matrix that lies between the endothelium of the glomerular capillaries and the podocytes of the inner or visceral layer of the bowman capsule. It is the product of these two cell types. It acts as a physical barrier and an ion-selective filter. Goodpasture Syndrome (GBM) disease, formerly known as Goodpasture syndrome Goodpasture Syndrome Goodpasture syndrome, also known as anti-glomerular basement membrane (GBM) disease, is an autoimmune disease characterized by circulating antibodies directed against glomerular and alveolar basement membranes. Affected individuals present with symptoms of rapidly progressive glomerulonephritis and alveolar hemorrhage. Goodpasture Syndrome
    • Cryoglobulinemic vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus (CV)
    • IgA IgA Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory iga is the main immunoglobulin in secretions. Immunoglobulins: Types and Functions vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus (IgAV), formerly known as Henoch-Schönlein purpura Henoch-Schönlein Purpura Henoch-Schönlein purpura (HSP), also known as immunoglobulin A vasculitis, is an autoimmune small-vessel vasculitis that typically presents as a tetrad of abdominal pain, arthralgia, hematuria, and purpuric rash. Henoch-Schönlein Purpura
• Variable-vessel vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus (VVV):
  • Behçet’s disease ( BD BD Blount’s disease (BD) is an orthopedic childhood disorder characterized by outward bowing of the leg due to abnormal ossification of the medial aspect of the tibial epiphysis. Blount’s disease mostly affects children of African descent and tends to debut at approximately 1–3 years of age. Blount’s Disease)
  • Cogan’s syndrome (CS)
• Single-organ vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus
  • Primary CNS vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus
  • Cutaneous leukocytoclastic angiitis (due to drug hypersensitivity Drug hypersensitivity Immunologically mediated adverse reactions to medicinal substances used legally or illegally. Type IV Hypersensitivity Reaction)
  • Isolated aortitis Aortitis Inflammation of the wall of the aorta. Ankylosing Spondylitis

Etiology

• Primary: idiopathic Idiopathic Dermatomyositis
• Secondary:
  • Triggered by viral infection (e.g., hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus or C) or toxin
  • Drug-induced
  • Related to connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology disease (e.g., systemic lupus or rheumatoid arthritis Rheumatoid arthritis Rheumatoid arthritis (RA) is a symmetric, inflammatory polyarthritis and chronic, progressive, autoimmune disorder. Presentation occurs most commonly in middle-aged women with joint swelling, pain, and morning stiffness (often in the hands). Rheumatoid Arthritis)
  • Related to malignancy Malignancy Hemothorax

Pathophysiology

• Can either be segmental or involve the entire vessel
• PMNs responsible for acute inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation
• Lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology responsible for chronic inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation
• Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the media of a muscular artery destroys the internal elastic Elastic Connective Tissue: Histology lamina.
• Resolution of the inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation can leave fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans and intimal hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation.
• Secondary clot formation can narrow the vessel lumen and cause tissue ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage.
• Predominant parenchymal inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation is a characteristic pattern that involves specific organs in different vasculitides.

Clinical Presentation

Takayasu’s arteritis

• Uncommon 
• Mostly in Asian women (< 50 years)
• Nonspecific symptoms may occur months before vascular symptoms.
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Malaise Malaise Tick-borne Encephalitis Virus
  • Night sweats Night sweats Tuberculosis
  • Arthralgias
  • Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa and weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways or tenderness of the blood vessels
• Unequal or absent pulses: 
  • Carotid
  • Radial
  • Other pulse areas

Giant-cell arteritis

• Associated with polymyalgia rheumatica Polymyalgia rheumatica A syndrome in the elderly characterized by proximal joint and muscle pain, high erythrocyte sedimentation rate, and a self-limiting course. Pain is usually accompanied by evidence of an inflammatory reaction. Women are affected twice as commonly as men and caucasians more frequently than other groups. The condition is frequently associated with giant cell arteritis and some theories pose the possibility that the two diseases arise from a single etiology or even that they are the same entity. Giant Cell Arteritis
• Mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion age at onset: 69 years
• Nonspecific symptoms:
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
  • Fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
• Specific to GCA GCA Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis:
  • Tenderness over the temporal arteries Temporal Arteries Arteries arising from the external carotid or the maxillary artery and distributing to the temporal region. Jaw and Temporomandibular Joint: Anatomy
  • Unilateral headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
  • Amaurosis fugax Amaurosis fugax Transient complete or partial monocular blindness due to retinal ischemia. This may be caused by emboli from the carotid artery (usually in association with carotid stenosis) and other locations that enter the central retinal artery. Carotid Artery Stenosis
  • Jaw claudication Jaw claudication Mandibular pain or fatigue during mastication that is relieved with rest Giant Cell Arteritis

Polyarteritis nodosa (PAN)

• Mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion age at onset: 45–50 years
• Constitutional symptoms Constitutional Symptoms Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis may occur months before vascular symptoms.
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and night sweats Night sweats Tuberculosis
  • Malaise Malaise Tick-borne Encephalitis Virus and fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
  • Arthralgias and myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus
  • Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa and weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
• Abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways (due to mesenteric artery vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus)
• Hematuria Hematuria Presence of blood in the urine. Renal Cell Carcinoma (due to renal artery Renal artery A branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters. Glomerular Filtration vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus)
• Dermatologic manifestations: 
  • Purpura
  • Nodules
  • Ulcerations
  • Livedo reticularis Livedo reticularis A condition characterized by a reticular or fishnet pattern on the skin of lower extremities and other parts of the body. This red and blue pattern is due to deoxygenated blood in unstable dermal blood vessels. The condition is intensified by cold exposure and relieved by rewarming. Chronic Kidney Disease
• Mononeuritis multiplex Mononeuritis Multiplex Chronic Diabetic Complications (such as foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy drop or wrist drop)
• 30% association with hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus, also with hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus
• Lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy/pulmonary arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology are not affected in PAN.

Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease

• Occurs in children
• Presents with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Bilateral conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
• Mucositis Mucositis Stomatitis is a general term referring to inflammation of the mucous membranes of the mouth, which may include sores. Stomatitis can be caused by infections, autoimmune disorders, allergic reactions, or exposure to irritants. The typical presentation may be either solitary or a group of painful oral lesions. Stomatitis (strawberry tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy)
• Desquamating rash Rash Rocky Mountain Spotted Fever on hands and feet
• Cervical lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy
• Potential complication of cardiac disease, including coronary artery Coronary Artery Truncus Arteriosus aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms

Granulomatosis with polyangiitis Granulomatosis with Polyangiitis A multisystemic disease of a complex genetic background. It is characterized by inflammation of the blood vessels (vasculitis) leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies (antineutrophil cytoplasmic antibodies) against myeloblastin. Granulomatosis with Polyangiitis

• Mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion age at onset: 45–50 years
• Presents with saddle nose Nose The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Nose and Nasal Cavity: Anatomy
• Recurrent sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis
• Epistaxis Epistaxis Bleeding from the nose. Granulomatosis with Polyangiitis
• Hematuria Hematuria Presence of blood in the urine. Renal Cell Carcinoma
• Unexplained hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis should always raise concern for alveolar hemorrhage and AAV AAV Antinuclear cytoplasmic antibody (ANCA)-associated vasculitis (aav) includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (mpa), and eosinophilic granulomatosis with polyangiitis (egpa). All 3 diseases cause life-threatening small-vessel vasculitis with a wide range of systemic manifestations, which can involve the lungs, kidneys, skin, and heart. Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis.
• Lab testing: proteinase 3 Proteinase 3 Granulomatosis with Polyangiitis (PR3)–ANCA-positive
• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma shows granulomas Granulomas A relatively small nodular inflammatory lesion containing grouped mononuclear phagocytes, caused by infectious and noninfectious agents. Sarcoidosis, pulmonary hemorrhage, pauci-immune glomerulonephritis (GN).

Eosinophilic granulomatosis with polyangiitis Granulomatosis with Polyangiitis A multisystemic disease of a complex genetic background. It is characterized by inflammation of the blood vessels (vasculitis) leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies (antineutrophil cytoplasmic antibodies) against myeloblastin. Granulomatosis with Polyangiitis

• Elderly individuals with new-onset asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma
• Cough, allergic symptoms
• Can have pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis
• Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions rash Rash Rocky Mountain Spotted Fever/nodules
• Mononeuritis multiplex Mononeuritis Multiplex Chronic Diabetic Complications
• Labs show eosinophilia Eosinophilia Abnormal increase of eosinophils in the blood, tissues or organs. Autosomal Dominant Hyperimmunoglobulin E Syndrome, 50% myeloperoxidase Myeloperoxidase Acute Myeloid Leukemia ( MPO MPO Acute Myeloid Leukemia)–ANCA-positive; chest x-ray Chest X-ray X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs. Pulmonary Function Tests abnormal
• Lung biopsy Lung Biopsy Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis shows eosinophilic infiltrates, necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage, and granulomas Granulomas A relatively small nodular inflammatory lesion containing grouped mononuclear phagocytes, caused by infectious and noninfectious agents. Sarcoidosis.

Anti– glomerular basement membrane Glomerular basement membrane The layer of extracellular matrix that lies between the endothelium of the glomerular capillaries and the podocytes of the inner or visceral layer of the bowman capsule. It is the product of these two cell types. It acts as a physical barrier and an ion-selective filter. Goodpasture Syndrome

• Constitutional symptoms Constitutional Symptoms Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis for a few weeks ( malaise Malaise Tick-borne Encephalitis Virus, weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, or arthralgias)
• 90% present with clinical features of rapid GN ( hematuria Hematuria Presence of blood in the urine. Renal Cell Carcinoma, hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, proteinuria Proteinuria The presence of proteins in the urine, an indicator of kidney diseases. Nephrotic Syndrome in Children).
• 25%–60% of individuals have concomitant alveolar hemorrhage.
• MPO MPO Acute Myeloid Leukemia–ANCA-positive

Cryoglobulinemic vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus

• Presentation related to serum cryoglobulins that precipitate in cold temperatures and dissolve upon rewarming and their deposition
• Palpable purpura
• Digit infarction
• Occasional mononeuritis multiplex Mononeuritis Multiplex Chronic Diabetic Complications or hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis
• Associated with:
  • Hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus
  • Multiple myeloma Multiple myeloma Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma
  • Lymphoproliferative disorders Lymphoproliferative disorders Disorders characterized by proliferation of lymphoid tissue, general or unspecified. Lymphocytosis
  • Connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology diseases
  • Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
  • Liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease
• Positive cryoglobulins, ↓ C3, C4, and rheumatoid factor Rheumatoid factor Antibodies found in adult rheumatoid arthritis patients that are directed against gamma-chain immunoglobulins. Autoimmune Hepatitis ( RF RF Rheumatoid Arthritis)–positive
• Immune complex GN

IgA IgA Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory iga is the main immunoglobulin in secretions. Immunoglobulins: Types and Functions vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus

• Mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion age at onset: 17–26 years
• IgAV of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions not the same as Burger IgA IgA Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory iga is the main immunoglobulin in secretions. Immunoglobulins: Types and Functions nephropathy
• Rash Rash Rocky Mountain Spotted Fever with palpable purpura; self-limited or treated with steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors

Behçet’s disease

• Recurrent painful oral aphthous ulcers
• Recurrent painful genital ulcers
• Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions lesions in 80%
  • Folliculitis
  • Acne-like rash Rash Rocky Mountain Spotted Fever
  • Erythema nodosum Erythema nodosum Erythema nodosum is an immune-mediated panniculitis (inflammation of the subcutaneous fat) caused by a type IV (delayed-type) hypersensitivity reaction. It commonly manifests in young women as tender, erythematous nodules on the shins. Erythema Nodosum 
  • Rarely: purpuric vasculitic rash Rash Rocky Mountain Spotted Fever
• May also have CNS, GI, ocular, or venous thrombotic manifestations

Cogan syndrome

• Presents with ocular inflammatory lesions:
  • Interstitial keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2
  • Uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea
  • Episcleritis
• Inner ear Inner ear The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. Ear: Anatomy disease symptoms
  • Sensorineural hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss 
  • Vestibular dysfunction
•  Vasculitic manifestations may include arteritis of any size vessel.

Cutaneous leukocytoclastic angiitis

• Also known as hypersensitivity vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus
• Presumed to be due to serum or drugs
• Single-organ, skin-isolated SVV without systemic vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus or GN
• Same cutaneous presentation as systemic SVVs
• Lesions with palpable and nonpalpable urticarial purpuric rash Rash Rocky Mountain Spotted Fever
• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma with immunofluorescence testing shows leukocytoclastic vasculitis Leukocytoclastic vasculitis Disorder characterized by a vasculitic syndrome associated with exposure to an antigen such as a drug, infectious agent, or other foreign or endogenous substance. Its pathophysiology includes immune complex deposition and a wide range of skin lesions. Hypersensitivity or allergy is present in some but not all cases. Henoch-Schönlein Purpura.
• Treatment involves removing the offending agent.

Diagnosis

History

• Symptoms that may characterize or exclude a suspected diagnosis
• Drug and medications that can cause vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus:
  • Hydralazine Hydralazine A direct-acting vasodilator that is used as an antihypertensive agent. Heart Failure and Angina Medication is the most common cause of drug-induced AAV AAV Antinuclear cytoplasmic antibody (ANCA)-associated vasculitis (aav) includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (mpa), and eosinophilic granulomatosis with polyangiitis (egpa). All 3 diseases cause life-threatening small-vessel vasculitis with a wide range of systemic manifestations, which can involve the lungs, kidneys, skin, and heart. Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis.
  • Propylthiouracil Propylthiouracil A thiourea antithyroid agent. Propylthiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of thyroxine to triiodothyronine. It is used in the treatment of hyperthyroidism. Antithyroid Drugs ( PTU PTU A thiourea antithyroid agent. Propylthiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of throxine to triiodothyronine. It is used in the treatment of hyperthyroidism. Antithyroid Drugs) and methimazole Methimazole A thioureylene antithyroid agent that inhibits the formation of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin. This is done by interfering with the oxidation of iodide ion and iodotyrosyl groups through inhibition of the peroxidase enzyme. Antithyroid Drugs are used to treat hyperthyroidism Hyperthyroidism Hypersecretion of thyroid hormones from the thyroid gland. Elevated levels of thyroid hormones increase basal metabolic rate. Thyrotoxicosis and Hyperthyroidism.
  • Minocycline Minocycline A tetracycline analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant staphylococcus infections. Tetracyclines
  • Cocaine Cocaine An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Local Anesthetics
• Infectious disease exposure:
  • Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus is associated with PAN.
  • Hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus is associated with CV.

Physical examination

• Identify potential sites of involvement of vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus and determine the extent of vascular lesions.
• Palpable purpuric rash Rash Rocky Mountain Spotted Fever
• Sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology or motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology neuropathy Neuropathy Leprosy
• Absent, unequal, or tender pulses

Laboratory tests

• Initial lab evaluation in suspected vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus includes:
  • Erythrocyte sedimentation rate Erythrocyte Sedimentation Rate Soft Tissue Abscess ( ESR ESR Soft Tissue Abscess)
  • CRP
  • CBC
  • Renal and hepatic function tests
  • Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus and C serologies
  • Serum cryoglobulins
  • Urinalysis Urinalysis Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically. Urinary Tract Infections (UTIs) in Children 
  • Blood cultures to exclude infection
• Additional testing may include:
  • ANA
  • Complement levels: ↓ C4 in cryoglobulinemia Cryoglobulinemia A condition characterized by the presence of abnormal quantities of cryoglobulins in the blood. Upon cold exposure, these abnormal proteins precipitate into the microvasculature leading to restricted blood flow in the exposed areas. Rapidly Progressive Glomerulonephritis
  • ANCA ANCA Group of systemic vasculitis with a strong association with anca. The disorders are characterized by necrotizing inflammation of small and medium size vessels, with little or no immune-complex deposits in vessel walls. Rapidly Progressive Glomerulonephritis antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions
  • Perinuclear ANCA ANCA Group of systemic vasculitis with a strong association with anca. The disorders are characterized by necrotizing inflammation of small and medium size vessels, with little or no immune-complex deposits in vessel walls. Rapidly Progressive Glomerulonephritis (pANCA)
  • Cytoplasmic ANCA ANCA Group of systemic vasculitis with a strong association with anca. The disorders are characterized by necrotizing inflammation of small and medium size vessels, with little or no immune-complex deposits in vessel walls. Rapidly Progressive Glomerulonephritis (cANCA)

Imaging

• Chest x-ray Chest X-ray X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs. Pulmonary Function Tests if pulmonary symptoms or hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis
• Vascular imaging with CT and MRI/ MRA MRA Imaging of the Heart and Great Vessels for suspected large-vessel vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus
  • MRA MRA Imaging of the Heart and Great Vessels of the affected area to look for stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) or poststenotic dilatation
  • Vascular ultrasonography
• Catheter-directed arteriography if no tissue available for biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma

Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma

• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma of the affected artery is the gold standard.
• May see on a temporal artery biopsy Temporal Artery Biopsy Giant Cell Arteritis in GCA GCA Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis:
  • Granulomatous thickening
  • Plasma cells Plasma cells Specialized forms of antibody-producing B-lymphocytes. They synthesize and secrete immunoglobulin. They are found only in lymphoid organs and at sites of immune responses and normally do not circulate in the blood or lymph. Humoral Adaptive Immunity and lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology in media and adventitia
  • Fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans

Management

• Immunosuppressive medications
  • Corticosteroids Corticosteroids Chorioretinitis
  • Nonbiologics: methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy, azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants, mycophenolate Mycophenolate Immunosuppressants, leflunomide Leflunomide An isoxazole derivative that inhibits dihydroorotate dehydrogenase, the fourth enzyme in the pyrimidine biosynthetic pathway. It is used an immunosuppressive agent in the treatment of rheumatoid arthritis. Disease-Modifying Antirheumatic Drugs (DMARDs), cyclophosphamide Cyclophosphamide Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the liver to form the active aldophosphamide. It has been used in the treatment of lymphoma and leukemia. Its side effect, alopecia, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer. Immunosuppressants
  • Biologics: tocilizumab Tocilizumab Immunosuppressants, rituximab Rituximab A murine-derived monoclonal antibody and antineoplastic agent that binds specifically to the cd20 antigen and is used in the treatment of leukemia; lymphoma and rheumatoid arthritis. Immunosuppressants 
• Antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs, if indicated
• Antivirals, if indicated, for hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus or C
• Intravenous immunoglobulin ( IVIG IVIG Dermatomyositis) for Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease
• For GCA GCA Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis:
  • Start steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors even before biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma, if clinically suspected.
  • If left untreated, potential complication of blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity
• Discontinue offending drug in MPA and EGPA.

Differential Diagnosis

• Systemic lupus erythematosus Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus ( SLE SLE Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus): chronic, autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Presentation includes malar rash Malar Rash Systemic Lupus Erythematosus, nondestructive arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis, lupus nephritis Lupus nephritis Glomerulonephritis associated with autoimmune disease systemic lupus erythematosus. Lupus nephritis is histologically classified into 6 classes: class I – normal glomeruli, class II – pure mesangial alterations, class III – focal segmental glomerulonephritis, class IV – diffuse glomerulonephritis, class V – diffuse membranous glomerulonephritis, and class VI – advanced sclerosing glomerulonephritis (the world health organization classification 1982). Diffuse Proliferative Glomerulonephritis, serositis Serositis Inflammation of a serous membrane. Systemic Lupus Erythematosus, cytopenias Cytopenias IPEX Syndrome, thromboembolic disease, seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures, and/or psychosis. Diagnosis is by finding antinuclear antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions, SLE-specific antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions, and specific clinical findings. Management is with corticosteroids Corticosteroids Chorioretinitis, hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants, and immunosuppressants Immunosuppressants Immunosuppressants are a class of drugs widely used in the management of autoimmune conditions and organ transplant rejection. The general effect is dampening of the immune response. Immunosuppressants. 
• Human immunodeficiency Immunodeficiency Chédiak-Higashi Syndrome virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology ( HIV HIV Anti-HIV Drugs): single-stranded RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology belonging to the Retroviridae Retroviridae The human immunodeficiency virus (HIV) is a species of Lentivirus, a genus of the family Retroviridae, which causes HIV infections and acquired immunodeficiency syndrome (AIDS). The virus has high genetic variability and is divided into 2 major types, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). The human immunodeficiency virus is a single-stranded, positive-sense, enveloped RNA virus, which targets and destroys WBCs, leading to frequent opportunistic infections and, eventually, death. Human Immunodeficiency Virus (HIV) family. HIV HIV Anti-HIV Drugs is the etiologic agent of AIDS AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS. The virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology attacks CD4+ T-lymphocyte cells, macrophages Macrophages The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood monocytes. Main types are peritoneal macrophages; alveolar macrophages; histiocytes; kupffer cells of the liver; and osteoclasts. They may further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or langhans giant cells. Innate Immunity: Phagocytes and Antigen Presentation, and dendritic cells Dendritic cells Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as skin and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process antigens, and present them to T-cells, thereby stimulating cell-mediated immunity. They are different from the non-hematopoietic follicular dendritic cells, which have a similar morphology and immune system function, but with respect to humoral immunity (antibody production). Skin: Structure and Functions. Presentation is with constitutional symptoms Constitutional Symptoms Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis, opportunistic infections Opportunistic infections An infection caused by an organism which becomes pathogenic under certain conditions, e.g., during immunosuppression. Autosomal Dominant Hyperimmunoglobulin E Syndrome and malignancies. Diagnosis is by enzyme immunoassay Enzyme immunoassay HIV Infection and AIDS for HIV-1 HIV-1 The type species of lentivirus and the etiologic agent of aids. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte. HIV Infection and AIDS and 2. Management is with combination antiretrovirals.
• Atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis: common form of arterial disease in which lipid deposition forms a plaque Plaque Primary Skin Lesions in the blood vessel walls. Atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis is an incurable disease, for which there are risk factors that often can be reduced through a change in the individual’s lifestyle and behavior. The manifestations of atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis depend on the specific vessels affected and include, most notably, coronary artery disease Coronary artery disease Pathological processes of coronary arteries that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause. Stable and Unstable Angina, carotid disease, and peripheral vascular disease.
• Ehlers-Danlos syndrome Ehlers-Danlos syndrome Ehlers-Danlos syndrome (EDS) is a heterogeneous group of inherited connective tissue disorders that are characterized by hyperextensible skin, hypermobile joints, and fragility of the skin and connective tissue. Ehlers-Danlos Syndrome: heterogeneous group of inherited connective tissue disorders Inherited Connective Tissue Disorders Ehlers-Danlos Syndrome that are characterized by hyperextensible skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions, hypermobile joints, and fragility of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions and connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology. The syndrome is due to genetic defects that affect collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology processing and synthesis Synthesis Polymerase Chain Reaction (PCR). Diagnosis is mainly clinical but is confirmed via genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies. There is no curative treatment. 
• Fibromuscular dysplasia Fibromuscular dysplasia Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory, medium-sized angiopathy due to fibroplasia of the vessel wall. The condition leads to complications related to arterial stenosis, aneurysm, or dissection. Fibromuscular Dysplasia: nonatherosclerotic, noninflammatory, medium-sized angiopathy due to fibroplasia Fibroplasia Fibromuscular Dysplasia of the vessel wall. This fibroplasia Fibroplasia Fibromuscular Dysplasia leads to complications related to arterial stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS), aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms, or dissection. Diagnosis is confirmed with imaging, and management includes lifestyle modifications, antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs, and potentially revascularization Revascularization Thromboangiitis Obliterans (Buerger’s Disease). 
• Thrombotic thrombocytopenic purpura Thrombotic thrombocytopenic purpura Thrombotic thrombocytopenic purpura (TTP) is a life-threatening condition due to either a congenital or an acquired deficiency of ADAMTS-13, a metalloproteinase that cleaves multimers of von Willebrand factor (VWF). The large multimers then aggregate excessive platelets resulting in microvascular thrombosis and an increase in consumption of platelets. Thrombotic Thrombocytopenic Purpura: life-threatening condition due to a deficiency of ADAMTS13. Clinical presentation can consist of thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, hemolytic anemia Hemolytic Anemia Hemolytic anemia (HA) is the term given to a large group of anemias that are caused by the premature destruction/hemolysis of circulating red blood cells (RBCs). Hemolysis can occur within (intravascular hemolysis) or outside the blood vessels (extravascular hemolysis). Hemolytic Anemia, hematuria Hematuria Presence of blood in the urine. Renal Cell Carcinoma, GI symptoms, neurologic symptoms, and renal involvement. Diagnosis is based on clinical symptoms and laboratory tests. Management includes plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products exchange and immunosuppressive therapies.
• Acute myeloid leukemia Acute Myeloid Leukemia Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the uncontrolled proliferation of myeloid precursor cells. Seen predominantly in older adults, AML includes an accumulation of myeloblasts and a replacement of normal marrow by malignant cells, which leads to impaired hematopoiesis. Acute Myeloid Leukemia: hematologic malignancy Malignancy Hemothorax characterized by uncontrolled proliferation of myeloid precursor cells. Clinical presentation consists of fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia, bleeding, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and infection related to the anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, and lack of functional WBCs. Diagnosis is via peripheral blood smear Blood smear Myeloperoxidase Deficiency and bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma examination showing myeloblasts. Management is mainly with chemotherapy Chemotherapy Osteosarcoma.