Do intestinal parasites enhance food allergy and atopic dermatitis?: A study in Warao Amerindian children

Abstract

Background: We evaluated the influence of intestinal parasitic infection on food sensitization associated to the severity of Atopic Dermatitis (AD) in a group of Warao Amerindian pre- school children. Methods: Feces examinations were performed in fresh stool specimens. Diagnosis of AD was done according to Hannifin and Rajka criteria and SCORAD index. Skin prick tests (SPT) were performed using extracts of cow’s milk (CM), hen’s egg (HE), Dermatophagoides pteronyssinus and Dermatophagoides farinae . Serum CM and HE-IgE levels (ELISA) were measured. Quantikine (R&D systems) assays were used for the determination of IL-13, TNF-a IL-6, and sCD23 in supernatants of CM- and HE- whole blood stimulated samples. Results: Atopic Dermatitis was reported in 23% of the children. It was significantly (p < 0.0001) associated toward both CM and HE- SPT positivity (p < 0.001). Giardia duodenalis infection (37%) was associated to the presence of AD (p = 0.005) and to a significant increase in the levels of CM stimulated TNF-a (p ¼ 0:006), IL-13 (p = 0.01), sCD23 (p = 0.001), CM-IgE (p = 0.012) and CM-SPT (p < 0.0001). Similarly, G. duodenalis infection was particularly associated with the increase on the levels of HE-stimulated TNF-a (p = 0.001), sCD23 (p = 0.001), HE-IgE levels (p = 0.002) and HE-SPT (p = 0.001). Conclusion: Gut inflammation caused by G. duodenalis may enhance food allergic reactivity contributing to the manifestation of AD in these children. However, other environmental factors (not considered in this work) as well as an atopic background among the Warao population would also contribute to the presence of AD.