Psoriasis

Overview

Epidemiology

• Relatively common in children and adults
  • 0.5%–11% of people worldwide
  • 1%–3% of people in the United States
• Can be seen at any age, but incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency peaks at the ages of 20–30 and 50–60 (median age is 28 years)
• ⅓ of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship have a first-degree relative with the disease.
• Seasonal variation: worse in winter Winter Pityriasis Rosea than summer
• Slightly more prevalent in women
• Men are more likely to have ocular disease.
• More common in Caucasians

Etiology

• Genetic predisposition
  • Major histocompatibility complex Major histocompatibility complex The genetic region which contains the loci of genes which determine the structure of the serologically defined (sd) and lymphocyte-defined (ld) transplantation antigens, genes which control the structure of the immune response-associated antigens, human; the immune response genes which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement. Innate Immunity: Phagocytes and Antigen Presentation (MHC) genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure → psoriasis-susceptibility locus Locus Specific regions that are mapped within a genome. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of chromosome 6. Many well known genetic loci are also known by common names that are associated with a genetic function or hereditary disease. Basic Terms of Genetics (PSORS1)
  • HLA-B27 → psoriatic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis
• Environmental triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency)
  • 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 → erythrodermic and plaque Plaque Primary Skin Lesions psoriasis
    • Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus → guttate psoriasis
    • 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) → erythrodermic psoriasis
  • Cold weather
  • Trauma 
  • Medications:
    • Lithium Lithium An element in the alkali metals family. It has the atomic symbol li, atomic number 3, and atomic weight [6. 938; 6. 997]. Salts of lithium are used in treating bipolar disorder. Ebstein’s Anomaly, beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers), and antimalarials are the most common. 
    • Interferon-alpha Interferon-alpha One of the type I interferons produced by peripheral blood leukocytes or lymphoblastoid cells. In addition to antiviral activity, it activates natural killer cells and B-lymphocytes, and down-regulates vascular endothelial growth factor expression through pi-3 kinase and mapk kinases signaling pathways. Interferons, tumor Tumor Inflammation necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage factor ( TNF TNF Tumor necrosis factor (TNF) is a major cytokine, released primarily by macrophages in response to stimuli. The presence of microbial products and dead cells and injury are among the stimulating factors. This protein belongs to the TNF superfamily, a group of ligands and receptors performing functions in inflammatory response, morphogenesis, and cell proliferation. Tumor Necrosis Factor (TNF))-alpha inhibitors, and nonsteroidal anti-inflammatory drugs ( NSAIDs NSAIDS Primary vs Secondary Headaches) may also contribute.
    • Corticosteroid use → pustular and erythrodermic psoriasis
  • Alcohol and tobacco use
  • Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care
  • Stress

Pathophysiology

Psoriasis is a complex disease marked by a deregulated T-cell–mediated inflammatory process, resulting in keratinocyte Keratinocyte Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Erythema Multiforme proliferation and dysfunctional differentiation.

• Not completely understood
• Initiation phase:  keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions respond to a trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation → stimulate 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 → cytokine production → T-helper cell differentiation 
• Maintenance phase: T-helper cells release Release Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane. Virology cytokines Cytokines Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner. Adaptive Immune Response → activate keratinocyte Keratinocyte Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Erythema Multiforme proliferation → activate more inflammatory cells, resulting in a self-amplifying inflammatory response
• Leads to:
  • Epidermal hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation (acanthosis)
  • Accelerated cell turnover → cell retention of nuclei in the stratum corneum Stratum corneum Skin: Structure and Functions ( parakeratosis Parakeratosis Persistence of the nuclei of the keratinocytes into the stratum corneum of the skin. This is a normal state only in the epithelium of true mucous membranes in the mouth and vagina. Actinic Keratosis)
  • Keratinocytes Keratinocytes Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. Skin: Structure and Functions fail to release Release Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane. Virology lipids Lipids Lipids are a diverse group of hydrophobic organic molecules, which include fats, oils, sterols, and waxes. Fatty Acids and Lipids needed for cell adhesions → leads to flaking, scaly plaques
  • Microabscesses
  • Vascular engorgement Engorgement Mastitis from superficial blood vessel dilation

Clinical Presentation

Major subtypes

• Chronic plaque Plaque Primary Skin Lesions psoriasis 
  • Most common form (approximately 80% of cases)
  • Symmetric, well-defined, salmon-colored plaques 
  • Thick, silvery scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions 
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
  • Most common locations:
    • Elbows (extensor side) 
    • Knees (extensor side) 
    • Scalp 
    • Umbilicus 
    • Gluteal cleft
  • Classification based on body surface area (BSA):
    • Mild-to-moderate disease → < 5% 
    • Moderate-to-severe disease → > 5% 
  • Nail involvement is common.
  • Auspitz sign: pinpoint bleeding with the removal of scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions
  • Koebner phenomenon Koebner Phenomenon Lichen Planus: lesions induced by trauma, such as scratching
• Guttate (“drop-like”) psoriasis 
  • Acute eruption of multiple small, salmon-colored papules
    • 1–10 mm MM 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 in size
    • Appear as “dew drops” with fine scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions
  • Found on the trunk and proximal extremities
  • Strong association with streptococcal 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
• Pustular psoriasis 
  • Painful patches Patches Vitiligo or plaques 
  • Localized: primarily involves the palms and soles
  • Generalized annular Annular Dermatologic Examination: 
    • Recurring, subacute eruption of annular Annular Dermatologic Examination erythematous plaques
    • Peripheral pustules and scale Scale Dermatologic Examination
  • Von Zumbusch variant: 
    • Widespread, painful erythematous patches Patches Vitiligo with pinhead-sized pustules
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may have 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, leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus, and hypocalcemia Hypocalcemia Hypocalcemia, a serum calcium < 8.5 mg/dL, can result from various conditions. The causes may include hypoparathyroidism, drugs, disorders leading to vitamin D deficiency, and more. Calcium levels are regulated and affected by different elements such as dietary intake, parathyroid hormone (PTH), vitamin D, pH, and albumin. Presentation can range from an asymptomatic (mild deficiency) to a life-threatening condition (acute, significant deficiency). Hypocalcemia.
    • Can have mucosal involvement
    • Life-threatening complications: sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock, neutrophilic cholangitis, pneumonitis Pneumonitis Human Herpesvirus 6 and 7, and acute respiratory distress syndrome Acute Respiratory Distress Syndrome Acute respiratory distress syndrome is characterized by the sudden onset of hypoxemia and bilateral pulmonary edema without cardiac failure. Sepsis is the most common cause of ARDS. The underlying mechanism and histologic correlate is diffuse alveolar damage (DAD). Acute Respiratory Distress Syndrome (ARDS)
  • In pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care, the condition is known as impetigo Impetigo Impetigo is a highly contagious superficial bacterial infection typically caused by Staphylococcus aureus (most common) and Streptococcus pyogenes. Impetigo most commonly presents in children aged 2 to 5 years with lesions that evolve from papules to vesicles to pustules, which eventually break down to form characteristic “honey-colored” crusts. Impetigo herpetiformis.
• Erythrodermic psoriasis 
  • Uncommon
  • Can be acute or chronic
  • Generalized erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion with varying scaling
  • Affects the entire body surface → ↑ risk of complications due to loss of 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 barrier
    • Sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock → 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 chills Chills The sudden sensation of being cold. It may be accompanied by shivering. Fever
    • Fluid loss → dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration and electrolyte imbalance

Special sites

• Inverse (intertriginous) psoriasis 
  • Found on intertriginous areas Intertriginous areas Malassezia Fungi: 
    • Inguinal
    • Perineal and genital 
    • Intergluteal 
    • Axillary 
    • Inframammary
  • Symmetric, smooth, shiny, erythematous plaques
  • Does not usually have a scale Scale Dermatologic Examination due to the moistness of the area
• Nail psoriasis
  • Tiny pits across the nail are characteristic.
  • Other findings:
    • Leukonychia (white lines or dots appearing on the nail)
    • Lunula Lunula Whitish crescent-shaped area at proximal end of the nail. Skin: Structure and Functions red spots 
    • Onycholysis (painless detachment from the nail bed Nail bed Skin: Structure and Functions)
• Palmoplantar psoriasis
  • Involves the palms or soles
  • Erythematous, hyperkeratotic plaques
  • Can have painful fissures

Associated disorders

• Psoriatic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis
  • Seen in up to 30% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with psoriasis
  • Can be disabling
  • Symptoms: 
    • Joint pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Back pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Morning joint stiffness
  • Exam findings:
    • Distal arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis, particularly of the distal interphalangeal (DIP) joints
    • Enthesitis Enthesitis Ankylosing Spondylitis ( 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 at site of tendon insertion) 
    • Tenosynovitis ( 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 fluid-filled sheath surrounding a tendon)
    • Dactylitis Dactylitis Ankylosing Spondylitis (“ sausage digits Sausage Digits Reactive Arthritis”)
    • Arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis mutilans (resorption of bones leading to soft tissue Soft Tissue Soft Tissue Abscess collapse)
    • Spondyloarthropathy Spondyloarthropathy Ankylosing Spondylitis
• Ocular disorders
  • Blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis ( 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 eyelid)
  • 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
  • Xerosis Xerosis Sjögren’s Syndrome (dryness)
  • Corneal lesions 
  • 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
  • Associated symptoms: 
    • Ocular discomfort 
    • Red eyes 
    • Swollen eyelids Eyelids Each of the upper and lower folds of skin which cover the eye when closed. Blepharitis 
    • Flaking or crusting in eyelashes 
    • Visual changes 
    • Psoriatic lesions on lids
• Comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus: 
  • Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity 
  • Metabolic syndrome Metabolic syndrome Metabolic syndrome is a cluster of conditions that significantly increases the risk for several secondary diseases, notably cardiovascular disease, type 2 diabetes, and nonalcoholic fatty liver. In general, it is agreed that hypertension, insulin resistance/hyperglycemia, and hyperlipidemia, along with central obesity, are components of the metabolic syndrome. Metabolic Syndrome 
  • 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 
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus 
  • Atherosclerotic disease
  • Inflammatory bowel disease 
  • Malignancy Malignancy Hemothorax 
  • Serious 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 
  • Autoimmune disorders

Diagnosis

Diagnosis is established by the clinical history and physical examination findings.

• 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 biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma
  • May be used for confirmation, but is rarely necessary 
  • Findings:
    • Acanthosis with elongated rete ridges Rete Ridges Lentigo Maligna
    • Parakeratosis Parakeratosis Persistence of the nuclei of the keratinocytes into the stratum corneum of the skin. This is a normal state only in the epithelium of true mucous membranes in the mouth and vagina. Actinic Keratosis 
    • Neutrophilic microabscesses (Munro’s microabscess)
    • Thinned, or absent, granular cell layer 
    • Dilated dermal papillary capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries: Histology
  • Periodic acid-Schiff-diastase (PAS-D) → rule out superficial fungal infection
• Screening Screening Preoperative Care and diagnosis of psoriatic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis
  • Physical exam findings
  • Negative rheumatoid factor Rheumatoid factor Antibodies found in adult rheumatoid arthritis patients that are directed against gamma-chain immunoglobulins. Autoimmune Hepatitis
  • ↑ erythrocyte sedimentation rate Erythrocyte Sedimentation Rate Soft Tissue Abscess ( ESR ESR Soft Tissue Abscess) and C-reactive protein (CRP)
  • HLA-B27 testing (helpful if 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 are absent)
  • Radiographs of affected joints and spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy 
    • Periarticular erosions Erosions Corneal Abrasions, Erosion, and Ulcers and bone resorption Bone resorption Bone loss due to osteoclastic activity. Bones: Remodeling and Healing → “pencil-in-cup” appearance
    • Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types proliferation → “fuzzy” appearance to the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types around the joint
    • Osteolysis Osteolysis Dissolution of bone that particularly involves the removal or loss of calcium. Paget’s Disease of Bone and articular collapse → arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis mutilans
    • Sacroiliitis Sacroiliitis Inflammation of the sacroiliac joint. It is characterized by lower back pain, especially upon walking, fever, uveitis; psoriasis; and decreased range of motion. Many factors are associated with and cause sacroiliitis including infection; injury to spine, lower back, and pelvis; degenerative arthritis; and pregnancy. Ankylosing Spondylitis

Management

Treatment is based on severity, lesion distribution, type, comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus, and response.

Treatment based on severity

• Mild-to-moderate disease:
  • Topical corticosteroids Corticosteroids Chorioretinitis ( hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants, triamcinolone Triamcinolone A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. Glucocorticoids, fluocinonide Fluocinonide Glucocorticoids)
  • Vitamin D Vitamin D A vitamin that includes both cholecalciferols and ergocalciferols, which have the common effect of preventing or curing rickets in animals. It can also be viewed as a hormone since it can be formed in skin by action of ultraviolet rays upon the precursors, 7-dehydrocholesterol and ergosterol, and acts on vitamin D receptors to regulate calcium in opposition to parathyroid hormone. Fat-soluble Vitamins and their Deficiencies analogs ( calcitriol Calcitriol The physiologically active form of vitamin d. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (calcifediol). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption. Parathyroid Glands: Anatomy, calcipotriene) 
  • Topical retinoids Topical retinoids A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic acne; psoriasis; and other disorders of keratinization. Acne Vulgaris (tazarotene)
  • Coal tar 
  • Phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn 
  • Calcineurin Calcineurin A calcium and calmodulin-dependent serine/threonine protein phosphatase that is composed of the calcineurin a catalytic subunit and the calcineurin B regulatory subunit. Calcineurin has been shown to dephosphorylate a number of phosphoproteins including histones; myosin light chain; and the regulatory subunits of camp-dependent protein kinases. It is involved in the regulation of signal transduction and is the target of an important class of immunophilin-immunosuppressive drug complexes. Vitiligo inhibitors ( tacrolimus Tacrolimus A macrolide isolated from the culture broth of a strain of streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. Immunosuppressants, pimecrolimus Pimecrolimus Immunosuppressants)
• Moderate-to-severe disease:
  • Retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies 
  • 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
  • Cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants
  • Apremilast Apremilast Phosphodiesterase Inhibitors (phosphodiesterase inhibitor)
  • Biologic agents Biologic Agents Immunosuppressants (note: TNF-alpha inhibitors can also exacerbate psoriasis)
  • Phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn

Adjuvant Adjuvant Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (freund’s adjuvant, bcg, corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity. Vaccination therapy

• Emollients Emollients Oleaginous substances used topically to soothe, soften or protect skin or mucous membranes. They are used also as vehicles for other dermatologic agents. Pityriasis Rosea
• Lifestyle modifications 
  • Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery 
  • Stress reduction
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases cessation

Additional considerations

• Inverse psoriasis:
  • Low-potency corticosteroids Corticosteroids Chorioretinitis 
  • Affected areas have an increased risk for corticosteroid-induced cutaneous atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation.
• Guttate psoriasis may resolve spontaneously without intervention.
• Pustular and erythrodermic psoriasis: hospitalization Hospitalization The confinement of a patient in a hospital. Delirium for severe disease and complications
• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may have refractory disease or suffer multiple relapses. 
• Goal of treatment is an approximately 75% reduction of psoriasis, or a reduction to < 3% of BSA.

Psoriatic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis

• Pharmacologic therapy: 
  • NSAIDs NSAIDS Primary vs Secondary Headaches for mild disease 
  • Biologics ( infliximab Infliximab A chimeric monoclonal antibody to tnf-alpha that is used in the treatment of rheumatoid arthritis; ankylosing spondylitis; psoriatic arthritis and Crohn’s disease. Disease-Modifying Antirheumatic Drugs (DMARDs), etanercept Etanercept A recombinant version of soluble human tnf receptor fused to an IgG Fc fragment that binds specifically to tumor necrosis factor and inhibits its binding with endogenous tnf receptors. It prevents the inflammatory effect of tnf and is used to treat rheumatoid arthritis; psoriatic arthritis and ankylosing spondylitis. Immunosuppressants, adalimumab Adalimumab A humanized monoclonal antibody that binds specifically to tnf-alpha and blocks its interaction with endogenous tnf receptors to modulate inflammation. It is used in the treatment of rheumatoid arthritis; psoriatic arthritis; Crohn’s disease and ulcerative colitis. Disease-Modifying Antirheumatic Drugs (DMARDs)) 
  • Disease-modifying antirheumatic drugs Disease-modifying antirheumatic drugs Disease-modifying antirheumatic drugs are antiinflammatory medications used to manage rheumatoid arthritis. The medications slow, but do not cure, the progression of the disease. The medications are classified as either synthetic or biologic agents and each has unique mechanisms of action and side effects. Disease-Modifying Antirheumatic Drugs (DMARDs) ( 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, 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)) 
• Nonpharmacologic therapy: 
  • Physical and occupational therapy Occupational Therapy Skilled treatment that helps individuals achieve independence in all facets of their lives. It assists in the development of skills needed for independent living. Fetal Alcohol Spectrum Disorder 
  • Exercise 
  • Orthotics 
  • Joint protection
  • Weight reduction

Differential Diagnosis

• Atopic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): a chronic inflammatory disease 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, usually due to a combination of genetics Genetics Genetics is the study of genes and their functions and behaviors. Basic Terms of Genetics, immunologic dysfunction, and environmental factors. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will have pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) and erythematous lesions on flexural surfaces, often with an exudative or weeping appearance. Silver scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions are not present. Diagnosis is based on history and exam, and will differentiate the condition from psoriasis. Treatment includes trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation avoidance, moisturizers, and topical 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. 
• Tinea corporis Tinea corporis Dermatophytes/Tinea Infections: a superficial cutaneous fungal infection. 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 examination will reveal a pink annular Annular Dermatologic Examination patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes with a scaling border and central clearing. Nail lesions may also be seen. These signs are not typically found in the characteristic locations of psoriasis. Diagnosis is mostly clinical. 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 scrapings can be taken for potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia hydroxide (KOH) preparation, which will show segmented hyphae Hyphae Microscopic threadlike filaments in fungi that are filled with a layer of protoplasm. Collectively, the hyphae make up the mycelium. Mycology. Treatment includes topical or systemic antifungal Antifungal Azoles medications.
• Nummular dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): 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 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, often seen in older patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship, and associated with dry 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. Exam will show pruritic, round, erythematous plaques on extensor surfaces that resemble psoriasis; however, these plaques are not typically scaly. Diagnosis is clinical, and treatment includes topical corticosteroids Corticosteroids Chorioretinitis, phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn, and supportive care.
• Seborrheic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): 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 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 in regions with a high sebaceous gland Sebaceous Gland Small, sacculated organs found within the dermis. Each gland has a single duct that emerges from a cluster of oval alveoli. Each alveolus consists of a transparent basement membrane enclosing epithelial cells. The ducts from most sebaceous glands open into a hair follicle, but some open on the general surface of the skin. Sebaceous glands secrete sebum. Hordeolum (Stye) density. The cause is unknown. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may present with scaling on the scalp and pruritis. Red papules with yellow scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions may also be seen. Seborrheic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema) can coexist with psoriasis, and the diagnosis is clinical. Topical antifungals, corticosteroids Corticosteroids Chorioretinitis, and calcineurin Calcineurin A calcium and calmodulin-dependent serine/threonine protein phosphatase that is composed of the calcineurin a catalytic subunit and the calcineurin B regulatory subunit. Calcineurin has been shown to dephosphorylate a number of phosphoproteins including histones; myosin light chain; and the regulatory subunits of camp-dependent protein kinases. It is involved in the regulation of signal transduction and is the target of an important class of immunophilin-immunosuppressive drug complexes. Vitiligo inhibitors may be used for treatment.
• Pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea: a self-limited inflammatory disease due to a viral infection (usually herpes 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). Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will present with pruritic, salmon-colored, oval plaques with scaling on the periphery. Pityriasis rosea Pityriasis rosea Pityriasis rosea is an acute, self-limited skin disease. The etiology is not known, and it commonly occurs in young adults. Patients initially present with a single, ovoid “herald patch.” This is followed by diffuse, pruritic, scaly, oval lesions over the trunk (often in a “Christmas tree” distribution on the back) and extremities. Pityriasis Rosea is characterized by a single herald patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes, followed by a “Christmas tree” pattern on the back. Diagnosis is clinical and will differentiate the condition from psoriasis. There is no specific treatment, so the focus is on symptom management with topical corticosteroids Corticosteroids Chorioretinitis and antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines.
• Lichen planus Lichen planus Lichen planus (LP) is an idiopathic, cell-mediated inflammatory skin disease. It is characterized by pruritic, flat-topped, papular, purple skin lesions commonly found on the flexural surfaces of the extremities. Other areas affected include genitalia, nails, scalp, and mucous membranes. Lichen Planus: a recurrent, idiopathic Idiopathic Dermatomyositis inflammatory condition that presents with pruritic, polygonal, purple papules and scaly plaques, which may be located on the wrists, lower legs, genitalia, and oral mucosa Oral mucosa Lining of the oral cavity, including mucosa on the gums; the palate; the lip; the cheek; floor of the mouth; and other structures. The mucosa is generally a nonkeratinized stratified squamous epithelium covering muscle, bone, or glands but can show varying degree of keratinization at specific locations. Stomatitis. Diagnosis is made based on clinical findings and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma, which will also show hyperkeratosis Hyperkeratosis Ichthyosis Vulgaris, but the condition does not have parakeratosis Parakeratosis Persistence of the nuclei of the keratinocytes into the stratum corneum of the skin. This is a normal state only in the epithelium of true mucous membranes in the mouth and vagina. Actinic Keratosis like psoriasis. Treatment includes 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, retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies, 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, and phototherapy Phototherapy Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths. Hyperbilirubinemia of the Newborn.
• Secondary syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis: a sexually acquired infection due to Treponema pallidum Treponema pallidum The causative agent of venereal and non-venereal syphilis as well as yaws. Treponema that can lead to a systemic illness. Findings include a diffuse, symmetric, scaly macular, papular, or pustular rash Rash Rocky Mountain Spotted Fever that is copper-colored, and can include the palms and soles. These plaques are generally smaller than in psoriasis. Diagnosis is made with a positive rapid plasmin Plasmin A product of the lysis of plasminogen (profibrinolysin) by plasminogen activators. It is composed of two polypeptide chains, light (b) and heavy (a), with a molecular weight of 75, 000. It is the major proteolytic enzyme involved in blood clot retraction or the lysis of fibrin and quickly inactivated by antiplasmins. Hemostasis reagin ( RPR RPR Treponema), and spirochetes Spirochetes An order of slender, flexuous, helically coiled bacteria, with one or more complete turns in the helix. Treponema may be seen on biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Penicillin Penicillin Rheumatic Fever G is the standard treatment.
• Lichen simplex chronicus Lichen Simplex Chronicus A benign vulvar skin disorder characterized by hyperkeratosis (thickening of the skin) that occurs secondary to chronic vulvar irritation Benign Vulvar Conditions: 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 changes that occur from excessive scratching. An underlying cause of pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) is usually present. Plaques of thickened 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 can develop with overlying scale Scale Dermatologic Examination and hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi, causing confusion with psoriasis. Areas that the patient cannot reach will appear normal, which helps distinguish the 2 conditions. Diagnosis is clinical and treatment focuses on relieving pruritis with corticosteroids Corticosteroids Chorioretinitis and antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines.
• Reactive arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis: an acute spondyloarthropathy Spondyloarthropathy Ankylosing Spondylitis that develops due to a gastrointestinal or genitourinary infection. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may have psoriasiform 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, asymmetric oligoarthritis Oligoarthritis Ankylosing Spondylitis of large joints, and constitutional symptoms Constitutional Symptoms Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis. The joints affected differ from psoriatic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis. Diagnosis is based on symptoms, exam findings, and the presence of an antecedent infection. Management includes treating the infection, NSAIDs NSAIDS Primary vs Secondary Headaches, 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, 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.