Study on the association of Toxocariasis with allergic rhinitis in individuals referred to Rasoul Akram Hospital, Tehran

Toxocariasis is a common worldwide zoonotic parasite infection caused by the larvae of Toxocara catti and Toxocara canis. Allergic rhinitis is the most common chronic diseases in the upper respiratory tract. The main symptoms are sneezing، watery rhinorrhea، itching in the nose، eyes and palate. The purpose of this study was to investigate the association between toxocara seropositivity and allergic rhinitis compared with the control population. This cross-sectional study was carried out from September 2009 to February 2011 on 93 patients with allergic rhinitis and 87 control subjects. Confirmation of the diagnosis of allergic rhinitis was defined by history and positive epicutaneous prick test. Control subjects were healthy based on history and no signs of allergic rhinitis and other allergic diseases were seen. Blood and fecal samples were taken from both groups. Sera were separated، labeled and stored at -20°C until used. Stool samples were examined by a wet mount and formalin-ethyl acetate concentration technique. The diagnosis of toxocariasis was established by IgG anti Toxocara and IgE total by ELISA method. In case group (allergic rhinitis) from 93 patients، 50 patients (53. 8%) were males and 43 (46. 2%) were female. In the control group of 87 individuals studied، 56 (64. 4%) were males and 31 (35. 6%) were female. In cases and controls، 5 (5. 4%) and 3 (3. 4%) of sera were positive for IgG Toxocara، respectively. There was no statistical difference in Toxocara seropositivity in both groups (p =0. 39). It seems to be in contrast to worms and allergies several factors، including phase worm infections (acute and chronic)، parasite load، parasite species and resistance genes are involved and this require further studies in different ages and populations.