Alpha-gal allergy after a tick bite in Austria

Tick bites can cause the alpha-gal syndrome, which is characterized by delayed anaphylactic reactions mainly to red meat and offal due to IgE antibodies against mammalian galactose-alpha-1.3-galactose carbohydrate (alpha-gal). Ixodes ricinus bites are considered the primary cause of IgE antibody responses specific for alpha-gal in Europe. This article reports on a 51-year-old Austrian male who acquired a tick bite in Austria in spring 2017, which, within 48 h, resulted in prolonged inflammation of the skin area around the bite. The patient experienced an allergic reaction 3 months later approximately 8 h after eating a medium rare steak for dinner. The symptoms included an itchy rash on both sides of the torso and on both arms which persisted for several hours. In spring 2018, the patient suffered another tick bite. The patient’s skin reaction was similar to that of the previous year. In the following months, the patient experienced five episodes of severe allergic reactions, each during the night after having eaten beef for dinner. The symptoms included pruritic urticarial rash involving the entire body along with swollen hands, diarrhea, vomiting and in some episodes even shortness of breath. At the request of the patient, specific IgE antibodies against alpha-gal were determined, revealing a highly positive result (>100 kU/l). This brief report aims to raise awareness that recurrent delayed anaphylactic reactions to food can develop after tick bites.