Allergic contact dermatitis caused by clindamycin

Abstract

A 58-year-old white woman was admitted with a clinical diagnosis of HS/AI that manifested at the age of 40 years. Dermatological examination showed HS/AI involving both inguinal folds, with inflammatory nodules, fistulae, and sero-purulent discharge. The patient complained of severe pain. The diagnosis of HS/AI (Hurley II stage) was confirmed. Laboratory examinations showed increases in total leukocyte number, erythrocyte sedimentation rate, and C-reactive protein level. Bacteriological examinations gave positive results for Staphylococcus aureus. According to an antibiogram, the patient was treated with amoxicillin (3 g/d for 10 days) and 1% clindamycin phosphate gel (Clindamicina SAME, with 2 applications per day for 10 days). One week later, the patient returned with an acute rash, characterized by erythema and vesicles, in both inguinal folds. She complained of severe pruritus. A diagnosis of contact dermatitis was made, and clindamycin treatment was stopped. The patient was successfully treated with hydrocortisone butyrate cream, and subsequently subjected to patch testing with the Società Italiana di Dermatologia Allergologica, Professionale e Ambientale (SIDAPA) baseline series, Clindamicina SAME gel and Zindaclin gel, both tested “as is”, clindamycin hydrochloride 1% pet., clindamycin phosphate 1% aq., and carbopol, glycerol, propylene glycol, methylparahydroxybenzoate, and propylparahydroxybenzoate, that is, the components of Clindamicina SAME (all of these substances were tested at the same concentrations as present in the gel). The procedure was performed according to ESCD guidelines. Positive reactions (++) to Clindamicina SAME, Zindaclin, clindamycin hydrochloride and clindamycin phosphate were observed on day (D) 2 and D4. Eight healthy volunteers showed negative results with all of the previously mentioned substances.