Galactose-α-1,3-galactose (α-Gal) syndrome considered to be in remission due to decreased α-Gal-specific IgE levels after tick avoidance instruction

Abstract

Galactose-α-1,3-galactose (α-Gal) syndrome is a syndrome in which delayed allergic symptoms are induced by veterinary meat containing the sugar chain α-Gal as a consequence of percutaneous sensitization to α-Gal via tick bites. It is expected that avoidance of ticks, which are the source of sensitization, may cause remission of this syndrome. We report here a case in which α-Gal-specific IgE levels decreased after instruction in tick avoidance, and the syndrome was considered to be in remission. A 15-year-old girl presented with anaphylaxis thought to be caused by beef, and was diagnosed with the syndrome because of a positive α-Gal-specific IgE level. The patient had a history of tick bites and kept many cats indoors and outdoors, and was instructed to keep cats outdoors for tick avoidance. α-Gal-specific IgE levels decreased from 3.61 before instruction to 0.40 17 months later. A 100 g heated beef challenge test conducted 25 months later was negative, indicating that the patient was in remission. Cats played an important role in α-Gal sensitization in the patient, and it was thought that the syndrome may have gone into remission because the patient was less likely to be bitten by ticks.