Predictors of Treatment Response in Localized Alopecia Areata: A Comparative Clinical Trial of Fractional CO₂ Laser versus Intralesional Corticosteroid Therapy

Open Access

Abstract

Background: Alopecia areata is an autoimmune disorder causing patchy hair loss and is commonly treated with intralesional corticosteroids, though their use is limited by pain, adverse effects, and recurrence. Fractional CO₂ laser therapy is an emerging alternative with promising outcomes, with treatment response influenced by disease severity, duration, and trichoscopic features. This study compares both modalities and evaluates predictors of therapeutic response. Methods & Materials: A prospective clinical trial at Combined Military Hospital (Jan-Dec 2024) enrolled 60 treatment-naïve patients (age 12-50) with patchy alopecia areata, divided equally into two groups (n=30 each). Group A received fractional CO₂ laser therapy (10,600 nm, 20-30 mJ, 100 MTZ/cm²; 4 sessions at 4-week intervals), while Group B received intralesional triamcinolone acetonide (5 mg/mL) at the same interval. Treatment response was evaluated after 16 weeks, with an additional 3-4 months follow-up. Data were analyzed using SPSS-23. Results: Clinical improvement occurred in 90.0% of the fractional CO₂ laser group and 83.3% of the intralesional corticosteroid group (p>0.05), with moderate response most common and greater marked improvement in the laser group. Short disease duration (<6 months) was the only independent predictor of good response (p=0.047; OR=4.21). Adverse effects were more frequent and severe with corticosteroids (pain, erythema, burning, atrophy), while the laser group had fewer and milder effects. No recurrence was observed in either group during follow-up. Conclusion: Fractional CO₂ laser therapy shows efficacy comparable to intralesional corticosteroids in Alopecia areata, with better safety and tolerability. Early disease duration is the strongest predictor of favorable response.