Progression From Acute to Chronic Urticaria

Importance: Progression from acute urticaria (AU) to chronic urticaria (CU) occurs in a subset of patients, but consistent factors associated with progression remain unclear. Identifying patients at risk could inform follow-up strategies and therapeutic decisions; however, evidence on prognostic factors is heterogeneous and uncertain. Objective: To systematically review clinical, laboratory, and treatment-related factors associated with progression from AU to CU. Evidence Review: A systematic search of MEDLINE, Embase, and Web of Science was conducted for English-language studies from database inception to December 31, 2025. Observational studies evaluating factors associated with chronicity in patients with AU were included. Paired reviewers independently screened studies, extracted data, and assessed risk of bias using an adapted Newcastle-Ottawa Scale and certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Due to heterogeneity, findings were synthesized qualitatively. Findings: Sixteen studies (52 564 total patients; sample size range, 57 to 49 129 patients) were included. Reported progression rates ranged from 5.8% to 36.0%, influenced by follow-up duration and outcome definitions, with higher rates potentially reflecting selection bias in tertiary centers. Clinical factors, such as disease severity, angioedema, allergic sensitization, and atopic status, showed inconsistent associations with chronicity. Laboratory markers, such as total immunoglobulin E, eosinophil counts, systemic inflammatory indices (including the neutrophil-to-lymphocyte ratio and systemic immune-inflammation index), and autoantibody profile, were not reproducibly associated with progression. Treatment-related factors, including the use of systemic corticosteroids during the acute phase, were not associated with reduced risk of progression. Overall, evidence quality was limited by methodologic heterogeneity, short follow-up, and moderate to high risk of bias. Conclusions and Relevance: This systematic review found that no single clinical or laboratory marker was consistently associated with progression from AU to CU, and current evidence does not support the use of aggressive treatment strategies during the acute phase solely to prevent chronicity. Careful clinical evaluation and structured follow-up remain essential, and emerging data on inflammatory and immunologic parameters may help identify subgroups at higher risk. These findings underscore the need for well-designed multicenter prospective studies with standardized outcome definitions and longer follow-up.