Comparison of patient characteristics in a retrospective well-phenotyped population with chronic inducible urticaria (CIndU), chronic spontaneous urticaria (CSU), and CSU/CIndU overlap
M. Caraghiulea1; AF. Mitra2; DO. Ogneva1; C. Motei1; L. Voicu1; IM. Ghiordanescu3, 4
1Prof. Dr. C.C. Iliescu Emergency Institute for Cardiovascular Diseases, Bucharest, Romania; 2Grigore Alexandrescu Emergency Clinical Hospital for Children, Bucharest, Romania; 3Elias Emergency University Hospital, Bucharest, Romania; 4Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
Background

Although in terms of diagnosis the international recommendations for chronic inducible urticaria (CIndU) are very clear on what concerns management options, the recommendations are mainly extrapolated from chronic spontaneous urticaria (CSU), due to a significantly lower number of CIndU patients compared to CSU. Furthermore, data regarding possible biomarkers for disease severity, patient characteristics, and predisposing factors for CIndU are scarce. The aim of our study was to comparatively evaluate patients characteristics in a retrospective population with chronic urticaria (CU).

Method

Data from patients with well phenotyped CSU, CIndU, and CSU/CIndU overlap, presenting in our Allergy Unit from 06.2020 to 12.2021 were retrieved from the electronic registry. Urticaria diagnosis and management were performed according to EAACI guidelines. Data were analysed using IBM SPSS Statistics26.

Results

Of 33 patients included in the study, 33.3% had CIndU, 24.2% CSU/CIndU overlap, and 42.4% had CSU. Overall, the most frequent Index CIndU was dermographism (24.2%), followed by cholinergic (15.2%) and delayed-pressure (12.1%) urticaria. Interestingly, vibratory angioedema and aquagenic urticaria were identified in 6% and 3% of the patients. Three patients had more than one CIndU type. Most frequent cofactor overall was infection (30.3%), with CIndU and CSU/CIndU overlap summing 80% of the cases. Atopy was present in 73% of the CIndU patients, although no significant difference was observed compared to the other groups. Overall, basopenia was present in 18.2%, autoimmune thyroiditis in 27.3%, raised CRP levels in 21.2%, with no significant difference between the groups. Seven patients with CIndU or CSU/CIndU overlap required biologic treatment, with six achieving complete or partial control, and one remaining uncontrolled.

Conclusion

In our small population of CU patients, CIndU was present alone in 33.3% and in combination with CSU in 24.2% of the patients. The most frequent CIndUs were dermographism, followed by cholinergic urticaria, as reflected by other published data. Most frequent cofactors were infections. Atopy was present in 72% of the CIndU patients. 63.15% of the patients with CIndU and CSU/CIndU overlap didn’t receive biologic treatment, while the rest received omalizumab, which achieved complete control in 85% of the patients.