Relapse rates and associated risk factors following omalizumab treatment in adolescents with chronic spontaneous urticaria.

Abstract

Background: Omalizumab is an effective treatment option for antihistamine-resistant chronic spontaneous urticaria (CSU) patients. This study aimed to evaluate relapse in patients after completing omalizumab treatment and identify associated risk factors.

Methods: Patients aged 12-18 years diagnosed with CSU who received omalizumab therapy between 2015 and 2023, whose treatment ceased with complete remission by December 2024.

Results: This study consisted of 59 patients with a median (interquartile) age of 14.0 (12.0-16.0) years, of whom 49.2% were female. Post-treatment relapse was observed in 47.4% (n = 28) of the patients, with a median time to relapse of 6.0 (4.0-7.5) months. Relapsed patients had an earlier onset of CSU than non-relapsed [11.9 (8.0-13.9) and 14.1 (11.5-15.9) years, p = .028]. The pre-treatment symptom duration was significantly longer in relapsed patients than in non-relapsed patients [21.0 (8.0-36.0) and 8.0 (6.0-21.0) months, p = .010]. Patients with symptoms longer than 7.5 months prior to starting omalizumab had a higher risk of relapse (AUC: 0.695, 95% CI: 0.561-0.830; p = .010; sensitivity: 82.1%, specificity: 45.2%). Pretreatment symptom duration was identified as a significant risk factor, increasing the likelihood of relapse (OR: 1.134, 95% CI: 1.011-1.272, p = .032). No significant differences were found between relapsed and non-relapsed patients in terms of other clinical and laboratory factors. Late relapse was more common in ANA-positive patients than early relapse [14 (87.5%) vs. 2 (12.5%), p = .021].

Conclusion: Delayed initiation of omalizumab treatment following the onset of urticaria symptoms is associated with an increased risk of relapse. Therefore, omalizumab treatment should be initiated promptly in eligible patients.