Can urticaria severity be used as a biomarker for transition from acute to chronic urticaria?

Abstract Background Acute urticaria usually resolves spontaneously; however, in some cases, it may progress to CSU. We aimed to investigate the underlying factors of AU in children and the clinical and laboratory factors affecting the progression of AU to CSU. Methods A prospective analysis was performed in 155 patients under 18 years of age who were diagnosed with AU and treated in our hospital. Factors affecting the transition from acute urticaria to chronic urticaria were analyzed using logistic regression. Results Progression of AU to CSU was observed in 9% of patients. The urticaria activity scores of the first week (UAS7) in patients who progressed to CSU were significantly higher than those of patients who did not develop CSU (UAS7: Median 14.5, Min–Max 6–32, p < .001). Additionally, elevated eosinophil levels (Median 3.6%, Min–Max 0–11, p = .006) and the need for more intensive treatments, including parenteral steroids, antihistamines, and additional therapies (42.9% of CU patients, p = .038), were identified as significant risk factors for progression to CSU. In univariate regression analysis, the UAS7 score was found to be statistically significant (OR: 1.131, 95% CI: 1.056–1.212, p < .001). In multivariate analysis, we found that high UAS7 scores (OR: 1.169, 95% CI: 1.072–1.275, p < .001) and the need for combined treatment with additional therapies (OR: 8.240, 95% CI: 1.007–67.441, p = .049) were independent risk factors for progression from AU urticaria to CU. Conclusion We found that the severity of urticaria during the first week and the need for additional therapies are important indicators in predicting the risk of chronicity. These findings may help to develop strategies to effectively manage AU in the early stages.