Clinical features of drug hypersensitivity reactions (1), (7), (8), (10), (13)
| Reaction | Clinical manifestations |
|---|---|
| Delayed drug exanthem | Fine macules and papules that occur days after drug initiation and resolve a few days after discontinuing the medication; lack of other systemic symptoms |
| IgE-mediated | Combination of urticaria, angioedema, vomiting, diarrhea, cough, wheeze, hypotension and/or syncope one to six hours after starting a medication; usually requires prior sensitization |
| Serum sickness-like reaction | Rash (usually urticarial), fever, arthralgias, lymphadenopathy one to three weeks after starting a medication; could be earlier with sensitization |
| SJS/TEN | Mucosal involvement, fever, cutaneous target and bullous lesions (SJS: < 10% epidermal detachment; SJS/TEN overlap: 10%–30% epidermal detachment; TEN: > 30% epidermal detachment); possible involvement of liver, kidney, lungs |
| DRESS | Fever, eosinophilia, lymphadenopathy, liver dysfunction, possible renal dysfunction, multiple different cutaneous eruptions possible; starts up to 12 weeks after starting a medication and may persist for weeks or months after stopping the medication (Figure 1) |
| Allergic contact dermatitis | Dermatitis in area of cutaneous contact that evolves over days; requires prior sensitization (Figure 2) |
| Drug-induced lupus erythematosus | Cutaneous: photodistributed erythematous plaques |
| Systemic: sudden onset myalgias, fever, arthralgias, malaise several weeks after drug initiation | |
| Fixed drug eruption | Hyperpigmented plaques that recur at the same site (Figure 3) |
| Other | Hematologic (cytopenia), hepatic (hepatitis, cholestatic jaundice), renal (interstitial nephritis), pulmonary (pneumonitis, fibrosis), vasculitis |
Note: DRESS = drug reaction with eosinophilia and systemic symptoms, IgE = immunoglobulin E, SJS = Stevens–Johnson syndrome, TEN= toxic epidermal necrolysis.