exanthemen

Exanthemen, or exanthems, are widespread skin rashes that accompany systemic illnesses or reactions to medications. They are typically maculopapular or vesicular and may be pruritic. The onset usually follows exposure to an infectious agent or a new drug, and the rash commonly begins on the trunk before spreading to the limbs.

Common causes include viral infections such as measles, rubella, roseola, and chickenpox, as well as bacterial infections like scarlet fever. Drug-induced exanthems are a frequent non-infectious cause and can result from antibiotics (notably beta-lactams), anticonvulsants, and other medications. The clinical pattern can vary, with morbilliform eruptions being the most typical; vesicular or crusting lesions occur with varicella or hand-foot-and-mouth disease. The rash may be accompanied by fever, malaise, sore throat, lymphadenopathy, or mucous membrane involvement in certain conditions.

Diagnosis is usually clinical, based on history and examination, with laboratory tests guided by the suspected underlying cause or complications. The differential diagnosis includes other drug eruptions, urticaria, pityriasis rosea, eczema herpeticum, and non-accidental causes of a purpuric rash.

Management focuses on treating the underlying cause and alleviating symptoms. Many viral exanthems resolve within about a week. Drug-induced exanthems typically improve after stopping the offending medication. Supportive care can include antipyretics for fever, antihistamines for itch, and basic skin care. Seek urgent evaluation for signs such as a non-blanching rash, high fever with poor perfusion, neck stiffness, severe headache, or signs of meningitis or sepsis.