Background: Eosinophilic cellulitis (Wells' syndrome) is a polyetiologic clinical entity with still obscure pathogenesis. Clinically overt toxocariasis is uncommon in adults, yet helminthozoonoses, including toxocariasis have been occasionally implicated in the pathogenesis of eosinophilic cellulitis.

Case representation: A 55-year-old female patient presented with a skin biopsy verified recurring febrile eosinophilic cellulitis, blood eosinophilia (42%), slight anaemia (Hct 35%), hepatosplenomegaly and positive specific anti-Toxocara canis antibodies. Toxocariasis-associated eosinophilic cellulitis was diagnosed. Already two weeks after treatment with thiabendazole the skin lesions resolved, T. canis antibody titre normalized eight months after treatment and no recurrences of eosinophilic cellulitis have been observed (for meanwhile three years).

Conclusion: The clinical characteristics (relapsing skin lesions, fever, hepatosplenomegaly), the laboratory features (blood eosinophilia, modest anemia, positive T. canis serology) and the clinical course after treatment, all support a causal relationship between Toxocara infection and the disease of this patient. We propose that in this context eosinophilic cellulitis must be interpreted as the leading symptom of a "skin-predominant" form of overt adult toxocariasis out of a spectrum of toxocariasis-associated febrile, "migrating-relapsing", organotropic eosinophilic inflammatory syndromes.