Abstract
BackgroundSubstantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent. Unlike to asthma, the association between helminthes infection and allergic rhinitis (AR) has been poorly studied. Therefore, we sought to evaluate the association between exposure to Ascaris and Toxocara infections and AR.MethodsWe did an age- and gender-matched case–control study of 81 children with physician-confirmed AR and 101 control subjects in a referral hospital for pediatric diseases in northern Iran. Exposure to Ascaris and Toxocara infections was evaluated by anti-A. lumbricoides- and anti-Toxocara- IgG antibodies using a commercial enzyme-linked immunosorbent assay. Associations were determined using multivariate logistic regression.ResultsAscaris seropositivity was higher in children with rhinitis than in controls (12.34 vs. 3.96%). Ascaris seropositivity was positively associated with AR in univariate analysis (OR, 3.42; 95% CI 1.03–11.3; P value = 0.035), but this association was not significant after adjustment for potential confounders (OR, 1.85; 95% CI 0.42–8.18). Also Toxocara seropositivity was higher in children with AR than in healthy subjects (3.7% vs. 0.99), indicating non-significant association with AR in both univariate (OR, 3.84; 95% CI 0.39–37.7) and multivariate analyses (OR, 0.8; 95% CI 0.04–15.44).ConclusionOur results revealed that AR is not associated with seropositivity to Ascaris and Toxocara infections in general; however, a higher seropositivity rate was found for both parasites in children with AR. More studies with longitudinal design and larger sample size are needed to elucidate this association.
Highlights
Substantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent
Some epidemiologic studies have shown that environmental exposure to products of infectious agents such as Mycobacterium spp, hepatitis A, and Toxoplasma gondii, have a protective effect against development of allergic rhinitis (AR), but infection with soil transmitted helminthes have yielded different results and most of epidemiologic studies and meta-analyses indicated that these infections are risk factors for development of allergic disorders
Two comprehensive meta-analyses have showed that Toxocara spp. and A. lumbricoides infections have a positive association to development of asthma [14, 18], but studies evaluating the association between these infection and allergic rhinitis are very rare
Summary
Substantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent. Some epidemiologic studies have shown that environmental exposure to products (e.g., endotoxins and lipopolysaccharides) of infectious agents such as Mycobacterium spp, hepatitis A, and Toxoplasma gondii, have a protective effect against development of AR, but infection with soil transmitted helminthes (such as Enterobius vermicularis, Toxocara spp. and Ascaris lumbricoides) have yielded different results and most of epidemiologic studies and meta-analyses indicated that these infections are risk factors for development of allergic disorders. Both Toxocara spp. and A. lumbricoides are ascarid nematodes with worldwide distribution [8, 9]. To our knowledge there are four studies evaluating association between Toxocara infection and AR [17, 19,20,21], showing conflict results, we have found only two relevant studies with respect to A. lumbricoides infection [21, 22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
