Fixed Drug Eruption: An Underrecognized Cutaneous Manifestation of a Drug Reaction in the Primary Care Setting

Fixed drug eruptions (FDEs) are dermatological manifestations of drug reactions that often occur in the same location upon re-exposure to a drug. They usually appear as erythematous-violaceous, circular patches, but several different variants have been described. They can often present without any associated symptoms, but in some cases, patients may complain of pain and pruritus. The lesions are often underdiagnosed or mistaken for insect bites, urticaria, or erythema multiforme; thus, an effort to bring awareness to this condition is warranted. We present a 33-year-old African-American female who presented to the urgent care presenting with several violaceous patches of varying sizes that started two days ago. The lesions were located on the left shoulder, abdomen, right flank region, and behind the right knee. The lesions were associated with mild pain and pruritus. She believed she was bit by insects but denied seeing any insects at home or participating in any recent outdoor activities. She stated that she had a similar rash in the exact locations five months ago. Upon survey of new medications, she stated that she recently started taking her medications again, which include: hydrochlorothiazide, semaglutide, vitamin D supplement, and ibuprofen. Examination of the skin revealed several black, non-blanching macules with a surrounding ring of erythema on the left shoulder (3 x 3cm), abdomen (4 x 3cm), right popliteal region (3 x 2cm), and right flank region (6 x 7 cm). She was prescribed a medium-dose topical steroid cream to apply to the skin twice a day to decrease the intensity of the inflammatory reaction and thus relieve her symptoms. She was also educated on FDEs and was advised to discontinue Ibuprofen, one of the most commonly implicated drugs in FDEs. Upon returning for a follow-up four weeks later, she noted that she discontinued Ibuprofen, and her cutaneous reactions had fully resolved. This case illustrates the prompt and accurate diagnosis of FDE leading to discontinuation of the offending drug and resolution of symptoms. It also represents the essential questions to ask when suspecting FDE.