Key Points Immunobullous diseases are a complicated multisystem management challenge requiring advanced immunosuppressive regimens. Pathogenesis has been linked to disease-specific autoantibodies to structural antigens within the epidermis and basement membrane zone. The location of blistering, risk of subsequent scarring, and…
Key Points Purpura has an extended and complex differential diagnosis, but can be sorted into three main pathophysiologies: simple hemorrhage, inflammatory (vessel-directed) hemorrhage, and microvascular occlusion. Recognition of patterns of morphology, number and distribution can rapidly narrow the diagnostic possibilities…
Key Points Erythroderma is erythema, with or without scaling, involving more than 90% of the cutaneous surface. Many cases of erythroderma are idiopathic, but the most common causes are exacerbation of an underlying skin disease, a drug hypersensitivity reaction, and…
Key Points Chronic itch can occur without primary skin rash associated with underlying systemic diseases. Itch can be the presenting symptom of lymphoma and hepatic diseases. Chronic systemic itch is associated with imbalance of μ versus κ opioids. Topical antipruritic…
Key Points The panniculitides comprise a heterogeneous group of inflammatory diseases that involve the subcutaneous fat. Various panniculitides may show the same clinical appearance, consisting of erythematous nodules, which frequently makes histopathologic study necessary in order to obtain the specific…
Key Points Herpes simplex virus infection is a frequent cause of erythema multiforme, while drugs most often cause Stevens–Johnson syndrome and toxic epidermal necrolysis. Erythema multiforme is often self-limited, skin lesions often target-appearing, and mucosal lesions can occur in the…
Key Points Urticaria is characterized by development of wheals and/or angioedema of the skin or mucosa. Individual lesions have a transient nature lasting less than 24 hours. Infection, drugs, chemicals, foods, inhalants, contactants, and physical stimuli are several recognizable triggers…
Key Points Peripheral blood eosinophilia provides clues to diagnosis, but it is not a diagnostic marker except when levels of peripheral blood eosinophils are in the “hypereosinophilic” range as found in the hypereosinophilic syndromes. Many diseases with increased peripheral blood…
Key Points Autoinflammatory syndromes are characterized by excessive multisystem inflammation from activation of innate pathways rather than the acquired immune system. Autoinflammatory syndromes are mostly rare monogenic disorders that generally first present in childhood. Most of these diseases are, at…
Key Points Rheumatoid arthritis (RA) is a multisystem disorder with many extra-articular manifestations that may affect the skin, including rheumatoid nodules and rheumatoid vasculitis. Rheumatoid nodules are the most characteristic cutaneous manifestation of RA. They, along with other extra-articular manifestations,…