Urticaria | Evanescent, pruritic wheals lasting <24 hours; angioedema of hands, feet, face | Penicillin-based antibiotics | Discontinue drug; start antihistamines (consider combination of H1-antihistamine and H2-antihistamine) |
Morbilliform eruptions | Symmetrical “measles-like” exanthem with erythematous macules and papules; may be pruritic | Antibiotics (e.g., penicillins and sulfonamides) | Discontinuation of drug advised although in some patients, reaction may resolve even if drug continued; antihistamines for pruritus; topical corticosteroids |
Erythema multiforme | Target lesions (dusky center, pale edematous rim with erythematous border) lasting >24 hours; mild mucositis (one mucous membrane, usually oral); may be mildly pruritic | Usually occurs with infections (e.g., herpes simplex) rather than drugs | Self-limited; supportive care |
Stevens–Johnson syndrome | Atypical target lesions; mucositis (2 or more mucous membranes) | Antibiotics (e.g., penicillins, sulfonamides); anticonvulsants (e.g., phenobarbital, phenytoin, carbamazepine); M. pneumoniae (may present with marked mucosal involvement with limited to no cutaneous involvement) | Prompt discontinuation of drug. Early initiation of systemic corticosteroids may be of benefit but use is controversial; severe cases may respond to IVIG; supportive care |
Toxic epidermal necrolysis | Extensive areas of tender, erythematous skin associated with skin sloughing and denudation; mucositis often present; patients typically ill-appearing | Antibiotics (e.g., penicillins, sulfonamides); anticonvulsants (e.g., phenobarbital, phenytoin, carbamazepine, lamotrigine) | Prompt discontinuation of drug. Early initiation of systemic steroids may be of benefit but use is controversial; severe cases may be successfully treated with IVIG; supportive care; monitor for systemic complications |
DRESS (drug reaction with eosinophilia and systemic signs), also known as drug-induced hypersensitivity syndrome | Exanthematous eruption associated with liver toxicity, fever, lymphadenopathy, eosinophilia, atypical lymphocytosis, although not all features may be present early in course | Aromatic anticonvulsants (e.g., phenytoin, phenobarbital, carbamazepine); sulfonamide antibiotics; minocycline | Discontinuation of drug; systemic corticosteroids; supportive care; monitor for systemic complications |