RESUMEN
INTRODUCTION: Alopecia areata (AA) is a challenging disease with variable treatment outcomes. Hair follicles express vitamin D receptors. Therefore, vitamin D3 may be promising for AA treatment through immunomodulatory mechanisms. The efficacy of bimatoprost in scalp AA treatment was reported by few studies. OBJECTIVE: To evaluate the efficacy and safety of microneedling (MN) with topical vitamin D3 versus MN with bimatoprost in comparison with MN alone in the treatment of localized AA. PATIENTS AND METHODS: Seventy-five patients with localized AA were divided into three groups. The first group: 25 patients were treated with MN alone. The second group: 25 patients treated with MN combined with topical vitamin D3. The third group: 25 patients treated with MN combined with bimatoprost solution. The response was evaluated clinically and dermoscopically. RESULTS: At the end of the study, all groups showed a statistically significant decrease in the SALT score compared to the baseline. The clinical response (regrowth scale): vitamin D and bimatoprost groups showed a statistically significant higher regrowth scale compared to MN alone group (p-value = 0.000). After treatment, hair regrowth was significantly higher in MN combined with bimatoprost than in MN combined with topical vitamin D3. However, after 3 months of follow-up, there was no statistically significant difference between both groups. Side effects were mild and transient in all groups. CONCLUSION: Topical vitamin D3 and bimatoprost combined with MN are safe and effective therapeutic options for localized AA.