Correlation of Tourette Syndrome and Allergic Disease: Nationwide Population-Based Case-Control Study

Objective: Linkage between allergy and increased immune response activation in Tourette syndrome (TS) has been reported. We performed a matched case-control study to evaluate correlation between allergic diseases and TS. Methods: Data in this case-control study were from the Taiwan National Health Insurance Research Database. The sample comprised 845 2- to 18-year-old patients with newly diagnosed TS in 2003-2007 and 3378 controls frequency matched with cases on age, sex, and urbanization level. Unconditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) of the association between allergic disease (e.g., allergic rhinitis, atopic dermatitis, asthma, and allergic conjunctivitis), the number of allergic comorbidities, and TS. Results: The majority (76.0%) of incident TS cases were boys; the 4 allergic diseases strongly correlated with higher risk of TS. In a model simultaneously considering all 4 allergic diseases, subjects with allergic rhinitis showed double the risk of TS (adjusted OR = 2.18, 95% CI 1.83-2.59; p < 0.0001); adjusted ORs were 1.82, 1.61, and 1.33, respectively, for asthma (95% CI 1.47-2.24; p < 0.0001), dermatitis (95% CI 1.32-1.95; p < 0.0001), and allergic conjunctivitis (95% CI 1.13-1.57; p < 0.001). Risk increased with number of comorbidities (p < 0.0001); this association was positively modified by age (p < 0.0001). Conclusions: Our data showed significant correlation between allergic diseases and TS. Risk also increased with number of allergic comorbidities and with age. Further studies on the mechanism of neuroimmunology of TS are required.