Anisakis poisoning (Paediatrics)

Anisakiasis (or anisakis poisoning) is the disease caused by infection with Anisakis worms, a genus of parasitic nematodes, whose life cycle affects fish and marine mammals, in which it can cause lesions in their digestive tract.

Humans are accidental hosts of this parasite. We can acquire the larvae if we eat raw, undercooked or uncooked parasitised fish or fish that we have not previously frozen.

Gastric manisfestation presents with abdominal pain, with or without nausea, vomit and diarrhoea, which may resemble the manifestations of other diseases such as appendicitis, ileitis (inflammation of the portion of the small intestine called the ileum), gastric ulcers, intestinal obstruction and even abdominal tumours. Cases of joint involvement and involvement of other organs (lung, liver, pancreas and spleen) have also been reported.

Diagnosis is made on the basis of a detailed clinical history and physical examination. Endoscopic techniques (gastroendoscopy or colonoscopy) allow the larvae to be seen and removed.

Symptomatic treatment is sufficient to get rid of this infection, as it usually clears up on its own over time. The best treatment for intestinal anisakis infection is early removal of the parasite by upper endoscopy. Some patients require removal of the worm by emergency surgery. For the treatment of allergic symptoms, antihistamines, corticosteroids, and even adrenaline are usually recommended in case of very severe symptoms.