Ankylosing Spondylitis (Clinical)
Overview Definition[1,9–11,19] Ankylosing spondylitis (AS) is a seronegative spondyloarthropathy characterized by chronic and indolent inflammation of the axial skeleton. Concept of spondyloarthropathy[5,19,20] Mnemonic To remember the seronegative spondyloarthropathies, use the mnemonic “PAIR.” Epidemiology[3,5–9] Etiology[3,5–9] Pathophysiology Proposed mechanism of inflammation[5–7,10] Axioskeletal changes[5,7,10] Clinical Presentation Articular manifestations[3,5–9] Extra-articular manifestations[3,5–9, 20] Physical examination[5,7,8,11] Diagnosis Suspected spondyloarthropathy[13,16,17] Refer patients […]
Osteomyelitis (Clinical)
Epidemiology and Etiology Epidemiology[1,7,8] Etiology and classification[1,3,7,8] Osteomyelitis is classified based on the route of infection. Non-hematogenous osteomyelitis (80% of cases): Hematogenous osteomyelitis (20% of cases): Risk factors[2,7,12,19] Table: Common causes of osteomyelitis based on patients’ underlying risk factors Risk factors Infectious agents No specific risk factor S. aureus Prosthetic joint replacement S. aureus S. […]
Angioedema (Clinical)
Overview Definition[2,6–8] Epidemiology[2,8,10] Etiology and Pathophysiology Classification[2,10,11] Angioedema may result from 3 primary mechanisms: General pathophysiology[8] Mast cell–mediated etiologies[2,11] Mast cell–mediated angioedema is typically associated with urticaria. Bradykinin-mediated etiologies[2,4,8] These etiologies are not associated with histamine release or urticaria. Other etiologies[2] Clinical Presentation Angioedema presents in various ways, depending on the site(s) and mechanism involved.[3,6,11] […]
Guillain-Barré Syndrome (Clinical)
Overview Definition[1–3] Epidemiology[1,3] Pathophysiology[1,3,4] Clinical Presentation Clinical symptoms vary based on the subtype of GBS. Individuals may have a history of respiratory or GI symptoms 1–4 weeks prior to the appearance of GBS. Acute inflammatory demyelinating polyneuropathy (AIDP)[1,3,6] Acute motor axonal neuropathy (AMAN)[3,6] Acute motor and sensory axonal neuropathy (AMSAN)[3,6] Miller Fisher variant[1,3,6] Bickerstaff encephalitis[1,2] […]
Tetanus (Clinical)
Overview Definition[1,2,5,6] Tetanus is a nervous system disorder caused by the bacterium Clostridium tetani. Etiology[1,2,5,6] Epidemiology[1,2,5,6] Mode of infection[2,3,5,6] Pathophysiology Types[2] Pathophysiology[1,2,6] Inoculation: Pathogenesis: Clinical Presentation and Diagnosis Clinical presentation[1,2,6] Generalized tetanus: Generalized tetanus is the most common and severe clinical form of tetanus. Neonatal tetanus: Local tetanus: Cephalic tetanus: Complications[2,10] Diagnosis[9,10] Management Management may […]
Subdural Hemorrhage (Clinical)
Overview Definition Subdural hematoma (SDH) is bleeding, usually caused by head trauma, into the space between the dural and arachnoid meningeal layers surrounding the brain, creating a space called the subdural space.[1] Epidemiology[1,11] Etiology[1,11] SDH is caused by rupture of vasculature (typically bridging veins) between the arachnoid and dural meningeal layers. The primary etiology is […]
Polycythemia vera (Clinical)
Overview Definition[12] Polycythemia vera (PV) is a chronic myeloproliferative neoplasm characterized by the overproduction of RBCs (erythrocytosis), WBCs, and platelets. This triad differentiates PV from erythrocytosis seen with chronic hypoxia and other conditions. Classification[10] Epidemiology[1] Etiology and Pathophysiology Etiology[6] Pathophysiology[7,9,12] Clinical Presentation Polycythemia vera is often diagnosed incidentally when a CBC obtained for other reasons […]
Donovanosis (Clinical)
Overview Definition Donovanosis, or granuloma inguinale, is an STD characterized by chronic progressive ulcers affecting the genital region. Epidemiology[1,2,5,6] Etiology[1,2,5] Pathophysiology[1,2] Clinical Presentation Signs and symptoms Complications[3–6] Diagnosis and Management The following information is based on US, UK, and European guidelines. Please see your local guidelines for additional guidance. Diagnosis Antibiotic therapy Management involves a […]
Fat Necrosis of the Breast (Clinical)
Overview Definition Fat necrosis is a benign breast lesion that results from injury to the breast tissue. Epidemiology[6] Etiology[6,7] Risk factors[6] Pathophysiology and Clinical Presentation Pathophysiology[5,6] Mechanisms of injury: Tissue response: Clinical presentation[5,6] Diagnosis History[6] Physical exam[6] Imaging[6] Image categorization system: BI-RADs Findings on breast imaging studies are classified according to the Breast Imaging Reporting […]
Iron Deficiency Anemia (Clinical)
Overview Definition Anemia is defined as a hemoglobin level that is 2 standard deviations below the mean for age, sex, and ethnicity. Because iron is a fundamental building block of hemoglobin, a deficiency in this mineral can result in decreased hemoglobin production and anemia. Epidemiology[1,2,5,9] Etiology[1,3–5,7] Pathophysiology Iron metabolism is a closely regulated complex balance […]