Beyond red meat: fish roe-associated reactions in patients with alpha-gal syndrome—a case series from Sri Lanka

Abstract Background Alpha-gal syndrome (AGS) is an IgE-mediated allergy to galactose-α-1,3-galactose (α-Gal), classically presenting with delayed allergic reactions after ingestion of mammalian-derived foods. Fish roe has recently emerged as a potential but under-recognized trigger in α-Gal-sensitized individuals. We describe the first South Asian case series of three patients with AGS who developed anaphylaxis following fish roe ingestion, highlighting this atypical trigger as a possible emerging cause of anaphylaxis associated with AGS in the region. Case presentation We retrospectively reviewed patients evaluated at a tertiary allergy clinic in Sri Lanka between January 2025 and May 2026 who developed allergic reactions following fish roe ingestion and fulfilled the diagnostic criteria for AGS based on a compatible clinical history, positive skin prick testing, elevated serum α-Gal-specific IgE, and symptom resolution following dietary avoidance. Three women aged 19, 45, and 53 years presented with anaphylaxis 5minutes to 1 hour after fish roe ingestion. All had clinical features suggestive of AGS, including delayed reactions to mammalian meat, gastrointestinal symptoms following dairy consumption, recurrent unexplained allergic episodes, and a history of tick exposure. Skin prick testing demonstrated sensitization to fish roe and mammalian-derived allergens, while serum α-Gal-specific IgE concentrations ranged from 1.55 to 12.7 kUA/L. Oral food challenges were not performed because of the risk of severe reactions. Following avoidance of mammalian meat, dairy products, gelatin and fish roe all patients remained free of further allergic reactions during follow-up. Conclusions Fish roe may represent an important and under-recognized trigger of immediate anaphylaxis in patients with AGS. Recognition of this atypical presentation is essential for timely diagnosis, appropriate dietary counselling, and prevention of recurrent life-threatening reactions. Larger mechanistic and epidemiological studies are needed to determine the prevalence and elucidate the underlying pathophysiological mechanisms of fish roe-associated reactions in AGS.