Therapeutic Effect of Superficial Cryotherapy on Alopecia Areata: A Prospective, Split-scalp Study in Patients with Multiple Alopecia Patches

BACKGROUND: Alopecia areata (AA) affects anagen hair follicles resulting in non-scarring hair loss. Since its introduction, superficial cryotherapy has been used as one of the meaningful treatment modalities for AA. OBJECTIVE: The purpose of this study is to clarify the therapeutic efficacy and safety of superficial cryotherapy for treatment of AA. METHODS: In 19 patients with multiple bilateral AA patches on their scalp, superficial cryotherapy was performed on the right side, every 2 weeks. Prednicarbate 0.25% solution was applied twice a day to both the treated and the control sides. Clinical improvement was estimated using the Severity of Alopecia Tool (SALT) score by 3 different dermatologists, along with the changes in terminal and vellus hair count and hair thickness analyzed by phototrichogram. RESULTS: After 4 months of treatment, mean terminal hair count on the right scalp was 1.6-fold increased (p=0.005), while mean terminal hair count on the left scalp showed no significant change (110.1% increase, p=0.285). Mean SALT score decrease on the right was 4-fold greater than that on the left (40.7% and 9.6%), without statistical significance (p=0.282). Mean vellus hair count and mean hair thickness did not show significant changes after superficial cryotherapy. No remarkable adverse event was observed. CONCLUSION: Superficial cryotherapy is an efficacious treatment modality with advantages of simplicity and noninvasiveness. It can be considered as a meaningful therapeutic modality for AA, especially when the disease status is limited to minimal to mild, or the conventional AA treatment is not applicable.