Association of psoriasis with allergic multimorbidity of asthma, rhinitis, and eczema among adolescents: a cross-sectional study

Background: Associations between psoriasis and allergic diseases (asthma, rhinitis, and eczema) in children have been reported in a limited number of studies, and the association between psoriasis and multimorbidity (co-occurrence) of allergic diseases remains unclear. Hence, this study aimed to assess the association between psoriasis and the co-occurrence of asthma, rhinitis, and eczema in adolescents. Methods: This school-based cross-sectional study enrolled adolescents (n = 3,864) aged 11–14 years. Parents completed a questionnaire on doctor-diagnosed psoriasis as well as symptoms and clinical history of asthma, rhinitis, and eczema. Eight nonoverlapping groups comprising single and co-occurring current (past 12 months) asthma, rhinitis, and eczema were identified. A multinomial logistic regression model was used to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI). Results: In the analytical sample (n = 3,710; 1,641 male and 2,069 female participants), 3.5% reported doctor-diagnosed psoriasis, and 15.7%, 15.0%, and 10.3% had current asthma, rhinitis, and eczema symptoms, respectively. Doctor-diagnosed psoriasis was associated with “asthma only” (aOR = 2.11, 95% CI: 1.15–3.89), “eczema only” (6.65, 4.11–10.74), “asthma + eczema” (5.25, 2.36–11.65), “rhinitis + eczema” (3.60, 1.07–12.15), and “asthma + rhinitis + eczema” (7.38, 2.93–18.58). Doctor-diagnosed psoriasis was not statistically significantly associated with “rhinitis only” (1.42, 0.71-–2.84) and “asthma + rhinitis” (1.78, 0.69–4.56). Conclusion: Our findings indicate that psoriasis is associated with the co-occurrence of allergic diseases among adolescents. However, further studies are required to investigate which biological mechanisms may be shared between psoriasis and allergic diseases.