Assessment of atopic dermatitis as a risk factor for chronic spontaneous urticaria in a pediatric population

Background: Atopic dermatitis (AD) and chronic spontaneous urticaria (CSU) represent two of the most common chronic inflammatory pruritic skin diseases. Any relationship between atopic skin disorders and CSU is controversial, mostly due to the paucity of relevant epidemiologic and pathogenetic data. Objective: To evaluate whether a history of AD in early childhood represents a risk factor for the subsequent occurrence of CSU in a pediatric population. Methods: Retrospective data of new cases of patients who visited the outpatient allergy unit of a tertiary pediatric hospital in Athens, Greece, between June 2014 and August 2016, were analyzed. Diagnoses of CSU and AD were based on diagnostic criteria proposed by the European Academy of Allergy and Clinical Immunology and the Hanifin and Rajka criteria, respectively. The data analyzed included CSU and AD diagnoses and the association with gender and season of birth as well as a personal and family history of allergy-related diseases (e.g., asthma, allergic rhinitis, AD, and food and drug allergies). Results: Records from 2261 children were included in the analysis (1365 boys; mean ± standard deviation [SD] age, 8.7 ± 5.8 years). Fifty-one children (31 boys; mean ± SD age, 9.1 ± 4.6 years) were diagnosed with CSU, whereas AD was reported in 761 children (466 boys; mean ± SD age, 5.2 ± 3.8 years). Multivariate data analysis showed that the children with a history of an early diagnosis of AD were at increased risk for later CSU occurrence (odds ratio 2.923 [95% confidence interval, 1.647-5.189], p < 0.001). No significant associations were observed with respect to other demographic and atopy-associated characteristics of the patients. Conclusion: Results of our study indicated that AD may constitute an important risk factor to the subsequent occurrence of CSU. This notion warrants further study with well-designed prospective cohorts.