Drug Rash with Eosinophilia and Systemic Symptoms (DRESS)

Usually develops over a few weeks, not an acute drug allergy!

Rash is maculo-papular, not specific.  Apart from eosinophilia, other blood abnormalities occur eg atypical lymphocytosis or lympho/thrombocytopenia.

The systemic features are fever and lymphadenopathy, but generally 1 or more organs, typically liver, kidney and lung involvement.