LAUSR

Granuloma annulare (GA) is a benign and typically selflimiting granulomatous disease of unknown etiology; it tends to resolve spontaneously over a period of months or years. It usually presents with annular lesions on the hands, upper limbs, trunk, or lower limbs; facial involvement is rare. It is associated with diabetes mellitus, paraneoplastic disorders, thyroid disturbances, and some drugs. A woman aged 38 years, with a personal history of an eating disorder for which she had been on treatment with topiramate for several months, was seen in dermatology outpatients for slightly pruritic lesions that had arisen on the dorsum of both her hands some months earlier. On physical examination, confluent papules with an annular morphology were observed on the dorsum of the fingers of both hands and over the metacarpophalangeal joints of the left hand (Figs. 1 and 2). Histology revealed focal degeneration of collagen and elastic fibers, mucin deposits, and a perivascular and interstitial lymphohistiocytic infiltrate in the upper and mid dermis, confirming the diagnosis of GA (Fig. 3). There were no significant findings in the blood tests requested. The patient was initially treated with topical tacrolimus and corticosteroids, and subsequently with oral corticosteroid therapy, with no improvement. On reviewing her medical history, we observed a chronological relationship between the introduction of topiramate and the appearance of the GA lesions. With a suspicion of GA secondary to topiramate, we decided, with the consent of the psychiatry department, to withdraw the drug, and this led to complete resolution of the lesions within a month. Four types of drug-induced granulomatous dermatitis have been identified: interstitial granulomatous dermatitis, exacerbation of rheumatoid nodules secondary to