Gastroallergic anisakiasis: findings in 22 patients

Ingestion of Anisakidae larvae in raw seafood may cause anisakiasis. However, despite the high level of consumption of seafood in Spain, only a few cases of anisakiasis have been reported until now. Anisakis simplex can cause allergic reactions in sensitized patients as a result of its parasitism in the gastrointestinal tract. The purpose of this study was to analyse the clinical findings in 22 patients with gastroallergic anisakiasis.

Patients with allergic and/or gastric symptoms after seafood ingestion were evaluated in the emergency room of the La Paz General University Hospital. Skin testing for Anisakis simplex and tests on the implicated seafood were performed and amounts of serum-specific immunoglobulin E were assessed. A gastroscopy was performed in those patients with severe allergic or/and persistent gastric symptoms after ingestion of raw or undercooked seafood.

Twenty-two patients were diagnosed with gastroallergic anisakiasis in 1 year. Most patients presented to the emergency room of our hospital with allergic symptoms. Gastric symptoms were usually moderate. Gastroscopy revealed local mucosal oedema and gastric erosion at the point of fixation. Two or more worms were detected in three patients. The mean time of latency of allergic symptoms was 5 h, while the mean time for gastric symptoms was 3 h.

Anisakis simplex parasitism was the causative agent of allergic and gastric symptoms. Gastroallergic anisakiasis appears to be a relatively common disease, that may have been underdiagnosed.