Drug-specific clinical pattern in fixed drug eruptions.

One hundred thirteen patients with fixed drug eruption (FDE) were studied for any drug-specific clinical pattern. The causative drugs were identified and confirmed by provocation tests. A trimethoprim-sulfamethoxazole combination caused maximum incidence (36.3%), followed by tetracycline (15.9%), pyrazolones (14.2%), sulfadiazine (12.4%), dipyrine (9.3%), acetaminophen (7.9%), aspirin (1.7%), thiacetazone (0.88%), and levamizole (0.88%). Sulfas, including trimethoprim-sulfamethoxazole, induced lesions on the lips (91%) and trunk and limbs (89%), with only minimal involvement of mucosae. Tetracycline caused lesions only on the glans penis, sparing other sites. Pyrazolones affected mainly the lips and mucosae, with a few lesions of the trunk and limbs. Dipyrine, aspirin, and acetaminophen caused lesions of the trunk and limbs, sparing the lips, genitalia, and mucosae. Levamizole caused associated constitutional disturbances with extensive skin lesions, as did thiacetazone. The current study indicates that the clinical pattern and distribution of lesions in FDE are influenced by the drug in question, and the study of the pattern may provide useful information in selecting the most likely causative drug, especially when the details of the drugs are unknown.