Systemic anaphylaxis after the ingestion of pancake contaminated with the storage mite Blomia freemani

Background Systemic anaphylaxis after the ingestion of mite-contaminated food has rarely been reported. Objective To describe an 8-year-old boy in whom systemic anaphylaxis developed shortly after the ingestion of pancakes prepared with commercial pancake flour. Methods The patient underwent skin prick testing for house dust mites and with uncontaminated and mite-contaminated pancake flour. Specific IgE for mites and the main ingredients of the pancake flour were also evaluated, with titers for Der p 1, Der f 1, and Blo t 5 quantitated using immunochemical methods. A sample of pancake flour was examined microscopically for mites. Results The patient had positive skin prick test results to contaminated pancake flour extract (1 g/5 mL), Dermatophagoides pteronyssinus , and Dermatophagoides farinae but a negative skin test response to uncontaminated pancake flour. The patient's serum specific IgE analysis was positive for antibodies to dust and storage mite allergens. There was no response, however, to the main ingredients of the pancake mix. Microscopic examination of the pancake flour revealed the storage mite Blomia freemani . Using an immunochemical assay, we found that the contaminated flour contained 5.4 μg/g of the allergen Blo t 5 but no Der p 1 or Der f 1. Conclusions This patient's anaphylactic episode was the result of ingestion of the storage mite B freemani . To our knowledge, this is the first reported systemic hypersensitivity reaction caused by this mite anywhere in the world.