Background: Chronic spontaneous urticaria (CSU) is a common inflammatory dermatosis characterised by recurrent wheals, pruritus, and angioedema persisting for six weeks or longer without an identifiable trigger. A substantial proportion of patients remain symptomatic despite standard antihistamine therapy, necessitating immunomodulatory alternatives such as autologous serum therapy (AST) and azathioprine.
Objective: To compare the efficacy and safety of AST and azathioprine in patients with CSU attending a tertiary healthcare centre in Uttar Pradesh.
Methods: In this prospective, interventional study, 60 patients with CSU aged 18–60 years were randomly allocated to two groups of 30. Group A received weekly intramuscular autologous serum injections for 9 weeks; Group B received oral azathioprine 50 mg/day for 12 weeks. Disease severity was quantified using the Total Severity Score (TSS) at baseline and at 4, 8, and 12 weeks. Clinical response, autologous serum skin test (ASST) status, antihistamine requirement, and adverse events were recorded.
Results: Baseline characteristics were comparable between groups (p > 0.05). Mean TSS fell from 13.3 ± 2.1 to 5.6 ± 1.8 in the AST group (57.8% reduction) and from 14.2 ± 1.9 to 3.4 ± 1.6 in the azathioprine group (76.1% reduction) at 12 weeks (p < 0.001). Total response rate was 73.3% with AST versus 83.4% with azathioprine, with complete remission in 23.3% and 46.7% of patients respectively (p = 0.038). ASST-positive status, shorter disease duration, absence of angioedema, younger age, and female sex were associated with better outcomes. Both therapies were well tolerated; no serious adverse events or treatment discontinuations occurred.
Conclusion: Azathioprine produced faster and more complete symptom control, whereas AST offered a safe, low-cost, minimally invasive alternative with a simpler monitoring burden. Treatment selection in CSU should be individualised according to disease severity, ASST status, comorbidity, and resource availability.