Intramuscular Corticosteroid Therapy in the Treatment of Alopecia Areata: A Time-to-Event Analysis.

INTRODUCTION

Intramuscular corticosteroids (IMC) have gained popularity for the treatment of severe alopecia areata (AA) in recent years; however, evidence on their efficacy and safety is still limited.

OBJECTIVE

To evaluate the efficacy, relapse rate, and tolerability of IMC in the treatment of AA, as well as factors associated with treatment outcomes.

METHODS

Time-to-event analysis was performed on patients with severe, extensive, or rapidly progressive AA receiving IMC. The IMC regimen comprised triamcinolone acetonide 20-40 mg/mL injected every 4-6 weeks. The evaluated outcomes included initial (25% regrowth), significant (75% regrowth), and complete hair regrowth (100% regrowth). Relapse and adverse events were also noted. Factors associated with treatment outcomes and relapse were analyzed using the Cox proportional hazards model.

RESULTS

A total of 101 patients were eligible for analysis. Significant hair regrowth was obtained in 80.2% of the patients (n = 81), in a median time of 3.4 months (95% confidence interval [CI] = 2.9-4.4). Complete hair regrowth was achieved in 48.5% of the subjects (n = 49), and relapse was observed in 47.5% (n = 48). Acneiform eruption was the most common adverse effect. Multivariable analysis revealed that nail involvement was a negative predictor of significant hair regrowth (adjusted hazard ratio [HR] = 0.04, 95% CI = 0.01-0.55; P = 0.015), whereas duration of AA longer than 6 months was associated with disease recurrence (adjusted HR = 4.02, 95% CI = 1.52-4.66; P = 0.005).

CONCLUSION

This study demonstrated the efficacy and safety of IMC in the treatment of severe or active AA; however, the relapse rate remained relatively high after discontinuation of the therapy. Nail involvement was a negative predictor of significant hair regrowth, while disease duration longer than 6 months predicted AA relapse.