Uncomplicated drug-induced disseminated exanthemas.

Exanthematous reactions with various morphological and localization patterns are the most frequently encountered adverse drug reactions involving the skin. The time course of benign exanthemas typically encompasses a few days to some weeks. They are not complicated by severe systemic symptoms or internal organ involvement. They manifest themselves in a polymorphous manner with primary efflorescences including macules, papules, and more rarely limited pustules, vesicles or bullae, followed by secondary lesions such as scales, and more rarely erosions and hemorrhage. Due to the limited inflammatory reaction pattern of the skin, these exanthemas may mimic other discrete skin disorders and infectious exanthemas. Rarely, typical skin disorders such as lichen planus or psoriasis are imitated or inflammatory reaction patterns such as Sweet's syndrome and erythema nodosum are observed. The most common groups of eliciting drugs include antibiotics, antiinfectious drugs, tuberculostatic drugs, anticonvulsant and antihypertensive agents. On the other hand, there are some drugs that have been very rarely associated with an adverse cutaneous reaction. Immunological effector mechanisms often include T cells and various chemokines and cytokines. Diagnosis is based on a detailed history, an exact morphological diagnosis and an accurate evaluation of the chronology. Histology may support the clinical diagnosis. After complete healing and within an interval of 6 weeks to 6 months, diagnostic skin and some in vitro tests are recommended. The treatment includes early withdrawal of the suspected culprit drugs, application of topical corticosteroids, systemic antihistamines and, if necessary, systemic corticosteroids.