Fixed drug eruptions caused by medications: a report from India.

Fifty-five patients with fixed drug eruption were investigated to determine the drug(s) causing the reaction. History, classic clinical features of well circumscribed erythema, edema and violaceous pigmentation, and the recurrence of the eruptions on the same sites on readministering drug were used as diagnostic criteria. This was confirmed by a provocative test. Sulfonamides and analgesics either alone or in combination were the most common causes of reaction.