Mites in the mix: Dust mite contamination of a flour product

• Published in: Journal of allergy and clinical immunology 2004-02, Vol.113 (2), p.S235-S235
• Main Authors: DeMerell, D.G., Olmos, C.E., El-Dahr, J.M.
• Format: Article
• Language: English
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2004.01.303

There have been at least three reported cases of anaphylaxis after ingestion of a commercial beignet (flour based fried donut) mixture containing dust mites (DM) or DM antigen. All of the patients were skin test positive to DM and negative to foods. Our objective was to determine the frequency of DM contamination in packages from local stores before and after opening. Twenty unopened packages of beignet mix with different expiration dates were collected. A sample from each package was examined by light microscopy and by rapid DM antigen kits using monoclonal antibodies against group II DM antigens. In six of the 8 unexpired boxes, DM were seen and the mixtures tested positive to DM antigen. Two of the 12 unexpired boxes contained DM and were antigen positive despite being well sealed. The DM positive packages contained visible brown areas within the mixture that represented contamination with DM. Packages were then closed with twist ties, stored at room temperature and re-examined at 2 weeks. DM were seen in 2 additional boxes and there was a marked increase in the number of DM seen in the previously contaminated boxes. Most (75%) of the expired boxes and 17% of the unexpired boxes contained DM prior to being opened. Exposure to air caused rapid mite proliferation once the packages were unsealed. In temperate climates, storage of this mix at room temerature may increase the risk of allergic reactions, including anaphylaxis, in those who are sensitized to DM.