Blastocystis sp. and Toxocara spp. Coinfection in Patients with Clinically Manifested Skin Allergy

In recent years, more and more publications reflect the relationship between clinically apparent allergy and infection with Blastocystis spp. or Toxocara spp. Our main goal is to examine allergy patients infected with Blastocystis sp. for the presence of anti-Toxocara IgG antibodies, intending to detect co-infection and its influence on the allergic condition of patients. For a period of 3 years (2020 – 2022), 1011 patients hos¬pitalized in the Allergology Clinic at the University Hospital, Pleven, were examined for intestinal protozoa and helminths. Fresh stool samples for microscopic parasitological examination were used. From persons infected with Blastocystis sp. venous blood was obtained for the determination of specific anti-Toxocara antibodies. Of the patients with allergic symptoms examined for intestinal helminths and protozoa, 40 were infected with Blastocystis sp. Out of them, seven (17.5%) were positive for anti-Toxocara IgG antibodies on the ELISA test, and Western blot confirms the diagnosis. All individuals with Blastocystis / Toxocara co-infection were established against the background of chronic urticaria, but no difference was found in the severity of clinical manifestations in comparison with those with only blastocystosis and those without evidence of parasitic infection. The data of our study, give us reason to consider that the establishment of parasitic infections in persons with skin allergic manifestations is not unusual, but in general, it is very difficult to determine whether they are the cause of the allergic condition or are a finding in the course of diagnostic clarification.