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Dermatologists define several broad categories of skin disease based on clinical features and pathophysiology. The categories that are of primary interest from an infectious disease perspective include bacterial and mycobacterial infections, fungal infections, protozoal infections, viral infections, reactive erythemas, drug- and viral-induced hypersensitivity syndromes, and vasculitic diseases and purpura (Table 13–1).
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Establishing the differential diagnosis of a rash relies both on an appropriately focused history and on correctly describing the morphology and distribution of the rash. A brief overview of common terms used in dermatology is presented in Table 13–2. Common patterns of distribution are presented in Table 13–3.
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