A prospective comparative study of two regimens of diphenylcyclopropenone (DPCP) in the treatment of alopecia areata

•Topical immunotherapy is among the best documented treatment modalities for alopecia areata.•Finding the best protocol for this type of immunotherapy remains a challenge.•We evaluated a novel method: multi-concentration patch test.•We revealed the effectiveness and safety of this novel method.•It was superior to conventional method regarding shortened duration of treatment and patient satisfaction. Alopecia areata (AA) is a chronic disorder and the best treatment regimen for it is unknown. Currently, one of the best documented treatment modalities for AA is topical immunotherapy. To evaluate the safety and efficacy of a novel method (multi-concentration patch test) versus standard protocol for topical immunotherapy. A prospective randomized clinical trial was conducted on 30 patients with Alopecia areata, half of them received DPCP with a novel method using multi-concentration patch test to determine the optimal initiating concentration of DPCP (case group) and the other half experienced immunotherapy according to the standard protocol (control group). Percentage of hair regrowth after 6 months of treatment and the incidence of drug-related adverse effects were evaluated and compared between the two groups. (IRCT registration code: IRCT20141209020250N5). Absolute and relative hair regrowth percentages were reported 25% and 41.49% in case group and 8.2% and 14.21% in control group respectively. Considerable response (more than 75% hair regrowth) was observed in 4 (26.6%) patients in case and 1 (6.6%) patient in control group. The clinical response was initiated about 7 weeks sooner in case compared to the control group (14 versus 7.38 weeks, P: 0.001). Overall, clinical response was higher in patients received new protocol, compared to control group. Moreover, patients who experienced new protocol had a higher level of treatment satisfaction in comparison with patients having standard protocol (P: 0.012). This study revealed the effectiveness and safety of the novel multi-concentration patch test DPCP therapy for AA and its priority to conventional method, at least in terms of shortened duration of DPCP immunotherapy.