# Efficacy and Safety of Long‐Term Azathioprine Therapy for Severe Alopecia Areata: A 10‐Year Cohort Study

## TL;DR

A 10-year study shows azathioprine is safe and effective for treating severe alopecia areata.

## Contribution

Long-term safety and efficacy of azathioprine for severe alopecia areata is demonstrated over a decade.

## Key findings

- Azathioprine led to 92.69% average hair regrowth over 10 years.
- Hair loss scores improved significantly from baseline to post-treatment.
- Treatment was well-tolerated with no major safety concerns reported.

## Abstract

Alopecia areata is an autoimmune disease in which T cells may play a key role in its pathogenesis. Various immunosuppressive drugs have been employed with varying degrees of success.

This study aimed to evaluate the long‐term efficacy and safety of azathioprine as a systemic monotherapy for moderate to severe alopecia areata.

A total of 63 patients (27 females [42.9%] and 36 males [57.1%]) with a minimum 6‐month history of alopecia areata were included. The extent of scalp hair regrowth was assessed during the treatment and annually for up to 10 years using the Severity of Alopecia Tool (SALT score). The primary endpoint was the percent change in SALT score during treatment. The daily dosage of azathioprine was calculated at 2 mg/kg of body weight.

The mean duration of the current episode of scalp hair loss was 34.10 months (±39.16). The mean percentage of hair regrowth was 92.69% (±9.08). The mean percentage of hair loss decreased from 74.2% (±27.8) before treatment to 5.2% (±8.6) after 10 years of azathioprine treatment, indicating a highly significant statistical improvement (Paired t‐test, 95% CI = 55.9–75.3). The mean hair loss score (S0–S5) improved from 5.56 (±1.3) before treatment to 0.67 (±0.53) after 10 years of treatment, showing a significant difference from the baseline score (Wilcoxon signed‐rank test, p < 0.0001).

This study demonstrates that azathioprine is a safe and effective systemic therapy for the treatment of recalcitrant and severe alopecia areata.