Prospective study of cutaneous drug reactions.

One hundred and seventy-five patients with cutaneous drug reactions were studied with regard to age, sex, possible causative drugs and clinical course of the reactions. The age of the patients ranged from 3 to 78 years old, with the common occurrence between the age of 20 to 30 years. Females outnumbered males at a proportion of 1.8:1. The maculopapular rash was the most common reaction, which accounted for 42.9 per cent of the patients. Fixed drug eruption and Stevens-Johnson syndrome were the second and third common occurrences. The eruptions were attributed to 45 drugs, the three most common causative drugs were ampicillin, penicillin and trimethoprim-sulphamethoxazole. Ampicillin was the most common drug that caused maculopapular rash whereas tetracycline and trimethoprim-sulphamethoxazole were responsible for fixed drug eruption and Stevens-Johnson syndrome respectively. The drug eruption occurred within a few minutes to 3 weeks of beginning therapy. The eruptions lasted from 3 to 30 days depending on the type of reactions.