Clinical and trichoscopic evaluation of trichloroacetic acid 35% vs phenol 88% peels in treatment of alopecia areata.

BACKGROUND

Among alopecia areata (AA) treatments, contact irritants (anthralin) and topical immunotherapies (diphenylcyclopropenone) have been successfully used. Chemoexfoliation can potentially be utilized, acting as irritants and consecutively immunomodulators. Peels via therapeutic wounding provoke growth factors and cytokines that may induce hair regrowth.

AIM: To evaluate and compare trichloroacetic acid (TCA) 35% and phenol 88% peels effectiveness and tolerability in patchy AA.

PATIENTS/

METHODS

This comparative, randomized, double-blind study included 20 patients with multifocal patchy AA. In each patient, 2 patches were selected and randomized into group I (20 patches: TCA 35%) and group II (20 patches: phenol 88%). A session was performed every 3 weeks for 9 weeks. Response was assessed by two blinded observers as regards percentage of clinical improvement, severity of alopecia tool (SALT), and trichoscopic scaled scores for dystrophic and terminal hairs, respectively. Patients were scheduled for follow-up visits over 6 months past treatment cessation.

RESULTS

A total of 19 patients completed the study and showed significant reduction in SALT score. TCA- and phenol-treated patches demonstrated significant improvement in the percentage of clinical improvement, trichoscopic scale of dystrophic and terminal hairs. However, TCA was superior to phenol as it showed significant more reduction in trichoscopic score of dystrophic hairs and significant higher increase in terminal hairs. Phenol yielded significant higher discomfort than TCA. No relapse was detected.

CONCLUSIONS

Trichloroacetic acid 35% and phenol 88% peels can be considered effective therapeutic modalities for patchy AA. TCA 35% represents a treatment of choice in terms of the efficacy and tolerability.