100186 - Something Fishy: Recurrent Angioedema Triggered by Environmental Exposure to Fish Allergens

A five-year-old girl with a history of atopic dermatitis was admitted to the Department of Pediatric Allergology for evaluation of recurrent episodes of facial angioedema. The first episode, involving swelling of the lips  and eyelids with accompanying pruritus, occurred one year earlier while the child was visiting her grandparents in a rural area and playing with a corn cob in a field. The symptoms resolved after treatment with antihistamines and intramuscular corticosteroids.

Subsequently, another episode of facial angioedema with urticaria occurred in a supermarket, followed by a similar reaction at home. The patient also experienced several episodes of mild eyelid edema, sometimes accompanied by urticaria, which responded to antihistamines. No clear association with food intake was initially identified.

During hospitalization, an extensive diagnostic workup was performed. The only abnormality was elevated specific IgE to multiple fish species (including herring, carp, cod, salmon, mackerel, tuna, swordfish, hake, and trout). The mother reported that the child avoided fish and disliked its taste. However, she recalled an earlier episode of lip erythema and swelling after contact with the breading of a fish stick. At the time, this reaction was attributed to a thermal injury.

Skin prick testing (with cod extract and prick-by-prick with cooked fish) yielded positive results and provoked localized urticaria at the test site followed by mild eyelid edema. Symptoms resolved after cetirizine administration; an exacerbation of atopic dermatitis was observed the following day.

Based on the clinical presentation and diagnostic findings, fish allergy was considered the underlying cause of the recurrent episodes of facial angioedema.

Environmental exposure was considered relevant: the field where the first reaction occurred had been fertilized with fish meal, a common agricultural protein source. After strict elimination of fish and fish-containing products, only one mild episode of facial swelling occurred, likely due to indirect contact with fish residues.

Written informed consent for publication of the clinical details and images was obtained from the patient’s parents.