Drug reaction rash with eosinophilia
If there is erythema then it will blanch, and if vasculitis then it will not blanch. The most obvious differential diagnosis is a viral exanthema. Patients with a viral infection usually have a fever, are systemically ill and have lymphadenopathy.
Patients with drug reactions generally do not show these features but of course there is overlap in conditions such as the Stevens-Johnson syndrome. This patient had a reaction to carbamazepine, started only three weeks before. She also developed liver and