Urticaria as Symptom of Parasite Migration Through the Biological Barriers

The absence of a consistent link between parasitoses and urticarial symptoms in the clinical investigations con- trasts to the fact that some parasites are the most potent inducers of immunoglobulin E that exist in nature. To shed some light into this question, this review is focused on the actual knowledge regarding parasites life cycle, interactions with host immunity, the influence on host behavior, and finally the role of all these factors on the urticaria development. The col- lected data demonstrate that parasites could manipulate the host behavior for its own benefit in different ways, inducing urticarial reactions during penetration into different biological barriers. In this context, urticaria may be associated with certain stages of the parasites' life cycle or with host tissue location, but not necessarily only with their presence in the host organism. As compared to T helper (Th) 1, the Th2 response, the eosinophilic infiltration and the complement inhibi- tion could assure a more pleasant surrounding area for the development of some parasites. Taken together, these concepts could explain the epidemiological discrepancy between low rates of urticaria occurrence, and the usual parasites-induced Th2 response. However, further studies are necessary to provide better-based conclusions.