Yes, I agree with both the docs above - this is most likely to be - Steven Johnson's syndrome ( although the classical 'bulls-eye' lesion is not seen - but that is usually seen in the earlier phase and once you have a full-fledged severe case, adjoining lesions merge into one another and the rash looks more morbilliform, like in this case. ) The most likely etiology is drugs, with the sulfonamides being particularly notorious. If the rash involves more than 30% body surface area, then I will call it 'toxic epidermal necrolysis'. Since the rash is morbilliform, I would like to keep - Measles as my second differential ( always imp. to keep this in mind as the patient population falling prey to measles is gradually shifting to higher age groups and there may be a need to consider re-vaccination of adults in the future ). Third differential would be the viral hemorrhagic fevers.
