Background: A history of atopic respiratory conditions has been linked to an increased risk of stroke. What remains unclear is whether positive allergy skin testing is associated with an increased risk of stroke. The primary goal of this study was to determine whether positive allergy skin testing is associated with an increased risk of fatal stroke. A secondary goal is to determine whether having both positive allergy skin testing and an atopic respiratory condition is associated with a particularly high risk of stroke death.
Methods: An analysis was performed of the National Health and Nutrition Examination Survey II Mortality Cohort.
Results: Controlling for age, gender, race, alcohol use, smoking status, diabetes, hypertension, and body mass index, patients with positive allergy skin testing had a hazard ratio for stroke mortality of 1.56 (95% CI, 1.01-2.40) versus those without positive allergy testing. Patients with both positive allergy testing and an atopic respiratory condition had a hazard ratio for stroke mortality of 2.31 (95% CI, 1.13-4.73).
Conclusions: Individuals with both positive allergy skin testing and an atopic respiratory condition have more than a 2-fold increased risk of fatal stroke. This novel risk factor has substantial implications for a large segment of the population not previously considered at risk.