Different freezing time of superficial liquid nitrogen cryotherapy in treatment of recalcitrant alopecia areata: Randomized clinical trial.

Recalcitrant alopecia areata is not uncommon in clinical practice and some patients experienced either treatment failure or recurrence with most of the conventional therapies. Several studies have evaluated the efficacy of cryotherapy in the treatment of alopecia areata with controversial results. This study aimed to optimize the ideal timing of liquid nitrogen cryospraying to achieve the most favorable results. A total of 75 patients with recalcitrant alopecia areata were treated with superficial cryotherapy, two freeze-thaw cycles, each consisted of 3 to 5, 8 to 10, and 13 to 15 seconds in group A, B, and C, respectively. Good to moderate improvement was achieved in 65.2%, 76%, and 76.2% in groups A, B, and C, respectively, with no statistically significant difference. However, the mean percentage of improvement was significantly higher in group B and C compared to group A (P-value < .05 for each). Superficial liquid nitrogen cryotherapy is an effective therapeutic modality for recalcitrant alopecia areata. Moreover, using 8 to 10 seconds dual freeze-thaw cycles is the optimum timing.