Allergen sensitization patterns in those who had idiopathic anaphylaxis (IA)
65 patients were classified as having IA, as we could not identify a cause from the history or by carrying out skin prick tests. Of them 42 (64.6%) were females and 49/65 (75.38%) were adults. 8/65 (12.3%) patients had grade 1 anaphylaxis, 46 (70.8%) had grade 2 anaphylaxis and 11 (16.9%) patients had grade 3 anaphylaxis. The allergen sensitization pattern of these 65 patients measured by ISAC Immunocap is shown in Table 1. 34 (52.3%) patients were found to have specific IgE to alpha-gal, while 11 (16.9%) were sensitized to cow’s milk. All 11 patients who were sensitized to cow’s milk were also sensitized to alpha-gal. The other main allergens that these patients were sensitized to were house dust mite in 20 (30.8%) patients, and grass pollen in 16 (24.6%). 7/65 (10.8%) of patients were found to be sensitized to tropomyosin and 5/7 (71.43%) of them were also sensitized to house dust mite. Although seven were sensitized to tropomyosin, only 4/7 (57.14%) of them had developed symptoms following ingestion of shrimp. 3/7 (42.86%) of those who had specific IgE to tropomyosin also had IgE to shrimp and only one of them reported a reaction following ingestion of shrimp.