Case Report: Toxocariasis as a rare trigger of vasculitis: a case-based review

Parasitic infections are increasingly recognized as potential triggers of autoimmunity and vasculitis, though evidence remains limited. Toxocara canis (T.canis), one of the most prevalent helminthic infections worldwide, has been sporadically linked to autoimmune phenomena through mechanisms such as molecular mimicry, immune complex formation, and chronic inflammation.

We describe a 45-year-old woman who developed histologically confirmed small-vessel vasculitis of the intestine with perforation, accompanied by cutaneous vasculitis, arthralgia, pruritus, eosinophilia, and elevated IgE and seropositivity for T. canis. Surgical resection with ileostomy led to spontaneous clinical remission without the need for immunosuppressive therapy. Immunologic evaluation revealed two coexisting organ-specific autoimmune diseases not typically associated with vasculitis: autoimmune thyroiditis (Hashimoto's) and autoimmune cholangitis. We reviewed the available literature on T. canis-associated autoimmunity and vasculitis, summarizing clinical presentations and patient outcomes.

Our report of histopathologically confirmed cases of small-vessel intestinal vasculitis associated with T. canis, leading to bowel perforation and remission without immunosuppression suggests that T. canis infection may represent an underrecognized trigger of autoimmunity and vasculitis. This case, together with a comprehensive review of the literature, indicates that T. canis infection should be considered in patients presenting with eosinophilia and elevated IgE, especially when accompanied by systemic or vasculitic manifestations.