Objective: To examine the relationship of past and current intestinal helminth infections with asthma, allergic rhinoconjunctivitis, atopic dermatitis and atopy.
Methods: Cross-sectional study of 1320 children aged 4-14 years from two Cuban municipalities. Helminth infections were determined by stool examination and parental questionnaire. Asthma, rhinoconjunctivitis and atopic dermatitis were diagnosed by International Study of Asthma and Allergies in Childhood questionnaire, asthma additionally by spirometry, atopy by skin prick testing.
Results: Questionnaire-based frequencies were 21% for asthma, 14% for allergic rhinoconjunctivitis and 8% for atopic dermatitis. According to spirometry, 4% had asthma; 20% had a positive skin prick test. A history of infection for Enterobius vermicularis was associated with increased risk of atopic dermatitis (OR 1.88, P = 0.001) and allergic rhinoconjunctivitis (OR 1.34, P = 0.046), and hookworm with increased risk of allergic rhinoconjunctivitis (OR 2.77, P = 0.021). A positive stool examination for Ascaris lumbricoides infection was negatively associated with atopic dermatitis (OR 0.22, P = 0.007). Asthma and atopy were unrelated to helminth infections.
Conclusion: Current A. lumbricoides infection protects against atopic dermatitis in Cuban children, while past infection with E. vermicularis and hookworm are risk factors for allergic rhinoconjunctivitis and/or atopic dermatitis. Apparently, interactions differ depending on the type of helminth and atopic disease and on the time of helminth infestation.