Anagen Effluvium due to Azathioprine in a Patient With Normal Thiopurine S-Methyltransferase Levels: A Case Report Using Videodermoscopic Analysis

Abstract

Introduction: Anagen effluvium (AE) is caused by impaired mitotic activity of matrix cells in the hair follicles. It presents with sudden loss of hair and myelosuppression. The diagnosis is based on the clinical history, trichoscopy, and trichogram. We herein report a case in which videodermoscopy revealed new trichoscopic features of AE caused by azathioprine in a patient with normal thiopurine S-methyltransferase (TPMT) levels. Case presentation: A 20-year-old woman presented with sudden loss of hair following treatment with oral azathioprine. Evaluation of the TPMT were within normal limits both in genotype and phenotype levels. Hair pull test was positive. Trichoscopy revealed yellow dots and multiple black dots, empty yellow dots, dark lines, upright regrowing hairs, and circle hairs. Azathioprine was stopped, and minoxidil 5% and oral multivitamin were started. Posttreatment trichoscopic analysis revealed terminal hairs and upright regrowing hairs. Discussion: AE is characterized by abrupt loss of anagen hairs due to impaired metabolic activity. Trichoscopy in AE shows coudability hairs, black dots, exclamation mark hairs, multiple broken shafts, and regrowing hairs. Empty yellow dots, yellow dots with black dots, pigtail hairs, and dark lines were additional features in this study. Conclusion: Trichoscopy assists in the accurate diagnosis of AE. Adverse effects of azathioprine can be observed even with normal TPMT levels. Weekly monitoring is therefore of prime importance.