Fixed Drug Eruption to Cetirizine: An Unusual Villain

A 21‐year‐old male patient presented to department of dermatology with chief complaints of itchy dark‐colored lesion over his left lower leg since 2 months. On examination there was single localized, scaly, hyperpigmented, and eczematous plaque. Diagnosis of nummular eczema was made and patient was advised topical steroid with emollients and oral cetirizine 10 mg per day to control pruritus. The following day, patient came back with multiple itchy dark color lesions associated with burning sensation over trunk, upper extremities, and buttocks. Lesions were multiple, well circumscribed, round, hyperpigmented patches with surrounding erythema [Figures 1a and b]. Patient gave the history of developing these lesions immediately 1 h after taking cetirizine. Oral cavity and genitals were not involved. Patient denied any history of oral cetirizine intake and similar complaints in the past. Patient was told to stop taking cetirizine and continue with emollients. Provisional diagnosis of FDE to cetirizine and erythema multiforme was made. Use of the Naranjo Adverse Drug Reaction (ADR) Probability Scale[1] indicated a probable relationship between this cutaneous adverse effect and cetirizine therapy in this patient. Histopathological examination revealed epidermal hyperplasia, spongiosis, interface vacuolar changes, pigmentary incontinence, and lymphocytes within basal layer. The dermis showed eosinophilic and neutrophilic perivascular infiltrate and extravasated red Address for correspondence: Dr. Kenit P. Ardeshna, Department of Dermatology, Venereology and Leprosy, MGM Medical College, Navi Mumbai, Maharashtra, India. E‐mail: [email protected]