New Study Reveals Risk Factors for Persistent Urticaria

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Urticaria is categorized into acute and chronic forms based on symptom duration. Acute urticaria (AU) is defined as the occurrence of wheals and/or angioedema for 6 weeks or less, while chronic urticaria (CU) refers to symptoms persisting for more than 6 weeks.¹ Acute urticaria typically resolves spontaneously; however, in some cases, it may progress to CU. Approximately 8% of patients with AU are reported to develop chronic spontaneous urticaria (CSU).² Currently, there is no definitive data on which types of patients are more likely to transition from AU to CSU. Although existing studies suggest that individual patient characteristics and underlying conditions may play a role in this progression, a clear model or guideline to predict this transition has not yet been established.1 The uncertainty regarding which patient groups are predisposed to chronicity in AU poses challenges in patient management and treatment strategies. Moreover, CSU is often difficult to manage and can significantly impair patients' quality of life.³

Due to these uncertainties, identifying the risk of chronicity in AU and developing effective treatment and management strategies are of great importance. However, specific risk factors associated with the progression of AU to chronicity have not been fully identified. Further research is needed to highlight potential risk factors and individual characteristics that may influence the chronicity of AU.⁴ In a recent prospective study, researchers aimed to investigate the underlying factors of AU in children and the clinical and laboratory factors influencing its progression to CSU.⁵

Study Methods

The study was a prospective analysis of pediatric patients treated at Prof. Dr. Cemil Taşcıoğlu State Hospital between July and October 2017. It included patients under 18 diagnosed with AU who presented to the pediatric allergy clinic. Diagnosis was made based on clinical presentation by a pediatric allergy specialist. Patients who progressed to CSU were included, while those with isolated chronic inducible urticaria were excluded.

For each patient, an “Acute Urticaria Form” recorded demographics, rash type, anaphylaxis symptoms, fever, infections, recent medication use, comorbidities, and family history of atopy. Serum total IgE levels and eosinophil counts were documented.

Disease severity was assessed using the Urticaria Activity Score (UAS7), which evaluates weekly symptoms based on wheal count and itch severity. Scores categorized disease as well controlled (0–6), mild (7–15), moderate (16–27), or severe (28–42). Follow-ups at 6 weeks assessed disease progression and chronicity.

Treatment was based on severity: second-generation antihistamines were first-line, with corticosteroids (0.5–1 mg/kg) added for severe or persistent cases. Additional therapies, such as antibiotics or leukotriene receptor antagonists, were used as needed.

Results

The study included 155 pediatric patients diagnosed with acute urticaria (AU), with a men to women ratio of 55% to 45%. The median age of the participants was 5 years. Among the observed urticaria phenotypes, isolated urticaria was the most common, accounting for 87.1% of cases, followed by urticaria with angioedema (10.3%) and isolated angioedema (2.6%). The presence of comorbid conditions, such as asthma, was identified in 14.8% of the study population.

The transition from AU to chronic spontaneous urticaria (CSU) was observed in 9% of the patients. Statistical analyses revealed that patients who progressed to CSU exhibited significantly higher Urticaria Activity Scores (UAS7) in the first week compared to those who did not (Median UAS7: 14.5, Min–Max 6–32, p < .001). Additionally, patients who developed CSU demonstrated higher eosinophil levels (Median 3.6%, Min–Max 0–11, p = .006), indicating a possible inflammatory component in disease chronicity.

A logistic regression analysis showed that each unit increase in the first-week UAS7 score was associated with a 1.131-fold increased risk of progression to CSU, and this association was statistically significant (p < .001). Multivariate regression analysis further confirmed that an increase in UAS7 score was a strong predictor of chronicity (OR: 1.169, 95% CI: 1.072–1.275, p < .001). Moreover, patients requiring additional therapies, including parenteral steroids, antihistamines, and adjunctive treatments, were at a significantly higher risk of developing CSU (OR: 8.240, 95% CI: 1.007–67.441, p = .049).

Conclusion

This study provides valuable insights into the progression of AU to CSU in a pediatric population. The findings highlight that the severity of urticaria within the first week of presentation, as measured by UAS7, is a significant predictor of chronicity. Additionally, elevated eosinophil levels may serve as an inflammatory marker associated with disease progression, though further research is needed to establish its independent role.

Patients requiring additional therapies beyond antihistamines were found to be more likely to experience chronicity, suggesting that refractory cases of AU may require closer monitoring and individualized treatment strategies. The study emphasizes the importance of early and systematic assessment of disease severity to identify high-risk patients and implement proactive management approaches.

References

1. Zuberbier T, Abdul Latiff AH, Abuzakouk M, et al. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022;77(3):734-766. doi:10.1111/all.15090
2. Ryan D, Tanno LK, Angier E, et al. Clinical review: The suggested management pathway for urticaria in primary care. Clin Transl Allergy. 2022;12(10):e12195. Published 2022 Oct 5. doi:10.1002/clt2.12195
3. Maurer M, Abuzakouk M, Bérard F, et al. The burden of chronic spontaneous urticaria is substantial: Real-world evidence from ASSURE-CSU. Allergy. 2017;72(12):2005-2016. doi:10.1111/all.13209
4. Kolkhir P, Giménez-Arnau AM, Kulthanan K, Peter J, Metz M, Maurer M. Urticaria. Nat Rev Dis Primers. 2022;8(1):61. Published 2022 Sep 15. doi:10.1038/s41572-022-00389-z
5. Yıldırım G, Ozceker D, Kaçar A, Yücel EÖ, Altınel ZÜ. Can urticaria severity be used as a biomarker for transition from acute to chronic urticaria?.Pediatr Allergy Immunol. 2025;36(3):e70053. doi:10.1111/pai.70053