common drugs = NSAID's, tetracyclines, sulfa drugs, phenopthalein
Clinical:
• | glans penis is most common site |
• | usually develops within 30 minutes to 8 hours of drug administration |
• | sometimes blister (subepidermal) |
• | dusky in center because of necrosis |
• | at the fixed drug site – will reproduce the lesion |
• | another site – no reaction |
distinctive variant:
"Non-pigmenting Fixed Drug Eruption":
• | large, tender, often symmetrical erythematous plaques |
• | "baboon syndrome" = where buttocks, groin, and axillae are preferentially involved |
histology:
• | dyskeratotic keratinocytes |
• | ddx: EM (histology = superficial), GVHD |
• | confident distinction among fixed drug, EM, and TEN based on biopsy alone, is not always possible |
|