Persistent, red plaques that only partially respond to steroids | Cutaneous T-cell lymphoma, connective tissue disorders |
Red plaques primarily in sun-exposed areas in patient with systemic complaints | Lupus erythematosus, dermatomyositis |
Urticaria-like lesions that last longer than 24 h | Urticarial vasculitis, prebullous pemphigoid |
Urticaria and/or angioedema in a patient with acute breathing difficulty (stridor) | Laryngeal edema, anaphylaxis |
Widespread vesicles or bullae, especially if mucosa is involved | Pemphigoid, pemphigus, Stevens–Johnson syndrome/toxic epidermal necrolysis |
Widespread areas of red painful skin | Stevens–Johnson/toxic epidermal necrolysis, staphylococcal scalded skin syndrome |
Widespread areas of peeling (desquamation) leaving areas of denuded skin | Stevens–Johnson syndrome/toxic epidermal necrolysis, staphylococcal scalded skin syndrome, toxic shock syndrome, exfoliative erythroderma |
Localized area of red, tender, warm skin | Cellulitis |
Dusky, red to blue, painful, edematous area; may have hemorrhagic bullae or crepitus | Necrotizing fasciitis |
Necrosis of the skin with ulceration and/or eschar | Occlusion or inflammation of blood vessels from arteriosclerosis, localized infection, sepsis, hematologic diseases, paraproteinemia, calciphylaxis |
Red or purple papules or macules that do not blanch | Purpura |
Purple or red papules primarily in children with fever and neurological symptoms | Rocky Mountain spotted fever, meningococcemia |
Rash and fever with multiple systemic complaints and findings | Exanthems due to certain infections |
Widespread persistent pruritus in patient with no primary skin disease | Liver, kidney, and myeloproliferative disease |