EARLY BIRD CATCHES THE SPOT: ACUTE FIXED DRUG ERUPTION

Abstract

Introduction Fixed drug eruption (FDE) is a recurring cutaneous reaction that characteristically occurs in the same location(s) upon re-exposure to the same drug. Lesions normally appear 8 hours and up to 2 weeks after drug administration. Case Description A 48-year-old female with a history of primary ciliary dyskinesia and bronchiectasis, lung transplant candidate, came into the Allergy Clinic after developing a hyperchromic macule on her left 4th finger two weeks after being put on trimethoprim-sulfamethoxazole (160 mg/800 mg) for a MDR Achromobacter infection. The lesion resolved within a month after suspending treatment with TMP-SMX. She denies similar episodes while off this antibiotic and with other drugs. An oral drug provocation test was performed with trimethoprim-sulfamethoxazole (160 mg/800 mg). Thirty minutes after receiving the antibiotic, the patient developed a flat, non-pruritic, erythematous macule on her 4th left finger. A biopsy of the lesion demonstrated changes consistent with early fixed drug eruption:focal interface dermatitis, papillary dermal eosinophils, and dermal pigment incontinence. Given the patient's history, she was not a candidate for desensitization. Therefore, she was recommended to avoid TMP-SMX and to use equally efficacious alternatives. Discussion FDE is a delayed hypersensitivity reaction mainly associated with CD8+ T cells. The lesions are typically round to oval, dusky, red to brown/black macules, plaques, or bullae that can appear anywhere on the body; however, hands, feet, lips, and genitalia are sites of predilection. While FDE is a delayed hypersensitivity reaction, there are some cases reported that occur as acutely as within 30 minutes. This is a documented case of such time-variation in presentation.