Alpha-gal syndrome (AGS) is an IgE-mediated allergy, triggered by a carbohydrate—galactose-α-1,3-galactose (α-Gal). AGS is marked by a delayed onset of symptoms, typically occurring 3–8 h after the ingestion of red meat or other mammalian-derived products. The primary risk factor is believed to be tick bites, which sensitize individuals through the introduction of α-Gal via tick saliva. Diagnosis of AGS is based on a combination of anamnesis and detection of α-Gal-specific IgE antibodies. We evaluated 28 patients with a history of unexplained anaphylaxis, angioedema, and/or urticaria, in whom the diagnostic work-up included the assessment of serum IgE specific to alpha-gal. Elevated alpha-gal-specific IgE levels were detected in five patients. Among them, four reported anaphylactic episodes following meat consumption. In three cases, symptoms developed during the evening or nighttime, typically 3 to 6 h after the last meal. One patient experienced anaphylaxis within one hour after a meal. Another patient presented angioedema up to 24 h after meat consumption and was also tested positive for specific IgE against beef and pork allergens. The AGS case series showed variability in clinical picture and time to reaction. In patients presenting idiopathic anaphylaxis and nonspecific symptoms after red meat consumption, AGS should be considered as a differential diagnosis.
Branicka et al. (2025) studied this question.