A Retrospective Review of Anthralin in Petrolatum in the Treatment of Alopecia Areata in the Pediatric Population.

Background/objectives: Alopecia areata (AA) is a T-cell driven autoimmune disease, which results in hair loss. This study aims to determine the efficacy, tolerability and safety of different concentrations of anthralin in the treatment of pediatric AA.

Methods: A retrospective cohort study of patients < 18 yo diagnosed with AA treated with anthralin at SickKids Hospital, Toronto dermatology outpatient clinic in 2016 - 2018. Anthralin used at 0.1%, 0.2%, 0.5% and 1% in petrolatum at short contact, at increments of 15 minutes every week until a 1 hr maximum contact achieved. No other treatment was used in conjunction. Severity of Alopecia Tool (SALT) scores (SS) were determined using photographs and descriptions to assess severity of alopecia at baseline and post anthralin treatment.

Results: A total of 11 charts were reviewed in this retrospective cohort. Hair loss pattern; 3 patients with patchy, 6 had mixed (patchy and ophiasis), and 2 were totalis. All except for 1 patient had failed traditional treatments. One patient had complete hair regrowth, 3 showed more than 85% hair re-growth and 7 patients showed more than 75% hair regrowth, the average time for this to occur was 6.5 months. None of the patients experience serious side effects.

Conclusions: Our study demonstrated the efficacy and tolerability of topical anthralin 0.1% to 1% in pediatric alopecia areata. In our study, anthralin 0.2% appears to offer the best performance and tolerability profile among the different concentrations used, with treatment course of at least 6 months in order to achieve more than 75% hair regrowth.