Abstract Purpura is an important physical finding, both for serious and incidental disease. The ability to rapidly sort through diagnostic possibilities depends on recognition of morphologic subsets of purpura, and…

Abstract Erythroderma is defined as erythema covering more than 90% of the body and can present with or without scale. Although many cases are idiopathic, investigation of underlying causes is…

Abstract Erythema multiforme (EM), Stevens–Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN) are immunologically mediated, mucocutaneous reactions triggered by medications and infections. Clinical presentation ranges from targetoid lesions in EM…

Abstract Pruritus affects millions of patients with skin and systemic diseases. Chronic pruritus is defined as an itch that lasts more than 6 weeks. It has a significant impact on…

Abstract The panniculitides are a group of heterogeneous inflammatory diseases involving the subcutaneous fat. The clinical findings are often insufficient for establishing diagnosis, and a biopsy is usually necessary to…

Abstract Urticaria, characterized by transient but recurrent swelling of the skin or mucosa, is a common dermatologic disorder. It can sometimes last for years and cause significant distress. Determining the…

Abstract Eosinophil-associated diseases are a spectrum of disorders in which eosinophils play a central role in the pathophysiology. Clinical manifestations result from activated eosinophils in tissues and/or from eosinophil-derived factors…

Abstract Neutrophilic dermatoses comprise a spectrum of skin diseases with various cutaneous manifestations and a predominantly neutrophilic infiltrate on histopathology. Neutrophilic dermatoses are associated with a variety of systemic diseases…

Abstract Autoinflammatory syndromes are a recently described group of disorders characterized by inflammation mediated by the innate immune system. All these syndromes have cutaneous presentations in addition to multiorgan involvement….

Abstract Cutaneous findings are commonly observed in rheumatologic conditions. These skin findings occur in association with underlying rheumatologic disease and are variably associated with disease state activity. In this chapter…