Best dilution of the best corticosteroid for intralesional injection in the treatment of localized alopecia areata in adults

PURPOSE: To evaluate and compare the clinical efficacy, dermoscopic results and safety of triamcinolone acetonide (TA) and betamethasone dipropionate (BD) injections at different concentrations in localized scalp and beard alopecia. METHODS: Intralesional injection of BD or TA in three different dilutions; 1/4, 1/8, 1/12 (BD1, BD2, BD3, TA1, TA2, TA3) and Saline (control) was randomly applied to a total of 231 alopecia patches in 83 patients every four weeks in a maximum of six sessions until a hair regrowth score of 4 was achieved. The number of required sessions, sixth-month hair regrowth scores, treatment success rates and dermoscopic data were investigated. RESULTS: The mean number of required sessions were similar and significantly lower in BD1 and TA1 being 4.21 ± 1.12 and 3.74 ± 0.99, respectively. Dermoscopic examinations revealed similar terminal hair growth rations in Saline (30.3%), BD1 (44.4%) and TA1 (42.9%). However, sixth-month hair regrowth scores, overall treatment success rates and percentage of terminal hair regrowth were similar in BD1 and TA1. However, adverse effects were more common in TA groups (24.3%) than in BD groups (10.6%) at the sixth month. CONCLUSIONS: BD ¼ dilution (1.25 mg/dL) seems best corticosteroid for intralesional injection in the treatment of localized alopecia areata in adults.