Direct immunofluorescence for the study of cutaneous drug eruptions

Forty-one patients with drug eruptions were retrospectively evaluated to correlate clinical, direct immunofluorescence, and dermatopathologic findings. Forty-six biopsy specimens were obtained for immunofluorescence in addition to specimens for dermatopathologic study. Eighteen patients had blood vessel fluorescence. Fourteen patients had basement membrane zone fluorescence. Eleven patients had dermatopathologic evidence of lichenoid changes; 8 of these had basement membrane zone fluorescence. Triamterene-hydrochlorothiazide caused the most eruptions (six patients). Positive direct immunofluorescence findings may aid the diagnosis of drug eruptions, especially in the presence of a nonspecific clinical picture or histopathologic findings.