Anaphylaxis caused by helminths: review of the literature

Abstract

BACKGROUND: Anaphylaxis is a severe, life-threatening, generalized or systemic hypersensitivity reaction. In many individuals with anaphylaxis a pivotal role is played by IgE and the high-affinity IgE receptor on mast cells or basophils. Less commonly, it is triggered through other immunologic mechanisms, or through nonimmunologic mechanisms. The human immune response to helminth infections is associated with elevated levels of IgE, tissue eosinophilia and mastocytosis, and the presence of CD4+ T cells that preferentially produce IL-4, IL-5, and IL-13. Individuals exposed to helminth infections may have allergic inflammatory responses to parasites and parasite antigens. AIM: To summarize the evidences about the role of helmiths in triggering anaphylaxis. MATERIALS AND METHODS: PubMed search was performed by combining the terms (anaphylaxis, anaphylactic, anaphylactoid) with each one of the etiological agents of human helminthiasis for the period January 1950 to September 2012. RESULTS: The PubMed search identified 609 papers. Only four genera of helminths were associated with anaphylaxis. (Echinococcus spp, 302 papers; Anisakis spp, 73 papers; Taenia solium cysticercosis, 7 papers; and Ascaris spp., 243 papers). CONCLUSIONS: The risk of anaphylaxis in patients with helminthiasis can vary according to the pathogens, occurring more frequently during echinococcosis of after anisakis infestation and being extremely rare after other helminth infestations. However, physicians, allergist and parasitologist in particular, should be aware of a potential anaphylaxis caused by helminths.