Lee S, et al. - According to standardized criteria for therapeutic hair regrowth and several prognostic factors, researchers analyzed the clinical outcomes of contact immunotherapy for alopecia areata via a systematic review and meta-analysis. Results revealed that various factors were correlated with the clinical outcomes of contact immunotherapy for alopecia areata, with significant differences in hair regrowth rates according to the level of expected therapeutic regrowth. The findings suggested that quantitative summarization might improve patient education and lead to better therapeutic adherence and outcomes.

Methods

• Using the search terms areata, totalis, universalis, sensitizer, sensitization, immunotherapy, DPCP, diphenylcyclopropenone, diphencyprone, SADBE, and squaric, researchers performed a database search of MEDLINE, Embase, and Cochrane Library for articles published before November 20, 2017.
• Clinical trials or observational studies that examined contact immunotherapy for alopecia areata and subgrouped the disease into patchy alopecia or alopecia totalis/universalis and reported their hair regrowth rates were involved.
• On the other hand, studies that investigated combination therapy or nonconventional protocol and case series or reviews were excluded.
• Study year and setting, sensitizer type, study population, study population composition by disease subtype, defined criteria for therapeutic hair regrowth, and regrowth rate of contact immunotherapy were the extracted data from each of the studies included in this meta-analysis.
• For this analysis, they recorded the incidence of adverse effects and recurrence rate.
• They used a random effects model for data synthesis because of the expected high heterogeneity of the involved studies.
• Therapeutic hair regrowth rate according to the 4-grade criteria for therapeutic regrowth was the main outcome.
• Incidence of treatment-related adverse effects and recurrence rate were the included secondary outcomes.

Results

• As per data, 45 studies involving 2,227 subjects were analyzed.
• Among patients with alopecia areata (74.6% in the patchy alopecia and 54.5% in the alopecia totalis/universalis subgroups), the overall rate of any hair regrowth was 65.5%.
• It was observed that the complete regrowth rate was 32.3% (24.9% in the patchy alopecia and 32.3% in the alopecia totalis/universalis subgroups).
• Findings revealed that disease extent of 50% or greater (odds ratio [OR], 3.05; 95% CI, 2.26-4.12), atopic history (OR, 1.61; 95% CI, 1.03-2.50), and nail involvement (OR, 2.06; 95% CI. 1.26-3.36) were related to poorer therapeutic outcome.
• Among patients receiving maintenance treatment, recurrence rates were 38.3%.
• Among patients not receiving maintenance treatment, recurrence rates were 49.0%.