D3.277 - Tolerance to canned fish in patients allergic to β -parvalbumins

It has been hypothesized that the canning process may reduce the allergenicity of β-parvalbumin. This study aimed to characterize tolerance to canned fish and cartilaginous fish (ray and monkfish) in patients with β-parvalbumin-mediated fish allergy.

This retrospective observational study, conducted between January 2020 and December 2024, included patients with β-parvalbumin allergy, defined by a suggestive clinical history, positive skin prick tests (SPT) to at least one fish extract and positive specific IgE to Gad c 1 (≥0.35 kUA/L by ImmunoCAP or ≥0.3 ISU-E by ISAC). Prick to prick tests (PTP) with canned fish were performed based on clinical history, SPT and specific-IgE results. We considered patients with negative PTP eligible for oral food challenge (OFC) with those fish. Demographic and clinical data, skin tests and analytical results and tolerance to canned fish, ray and monkfish were collected from patients reports.

Twenty-one patients were included (66.7% male), with a median age at first fish reaction of 3 ± 10 years. The most frequently implicated fish species were hake (66.7%), cod (50%), and sardine (27.8%). Anaphylaxis was reported in 7 patients (33%), and 4 of these experienced respiratory symptoms upon exposure to fish cooking vapors. Mean IgE to Gad c 1 was 14.1 ± 18.9 kUA/L. Prior to follow-up, 9 patients tolerated canned tuna, 1 tolerated ray and 1 monkfish based on clinical history.

Twelve patients underwent OFCs with canned fish, all of which were negative: tuna (n = 5), mackerel (n = 4), sardine (n = 2), horse mackerel (n = 1), and salmon (n = 1). OFCs with ray and monkfish were performed in 8 and 2 patients, respectively, with negative results. Of the remaining 9 patients, OFCs were pending or declined.

Overall, 14 of 21 patients (66.7%) tolerated canned tuna; among these, 5 also tolerated other canned fish, 9 tolerated ray and 3 monkfish, either from clinical history or after a negative OFC. 

In patients with β-parvalbumin–mediated fish allergy, canned tuna and ray are frequently tolerated, and in nearly one quarter of patients it was possible to introduce other canned fish, improving nutritional intake and dietary diversity. The introduction of canned fish in selected patients may improve quality of life and reduce nutritional deficiencies.