Anaphylaxis to Oatmeal and Psocid Crisps

  • Delara Babaei Division of Clinical Immunology and Allergy, Department of Medicine, St. Michael’s Hospital, University of Toronto, Toronto, Canada AND Department of Allergy and Clinical Immunology, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Peter Vadas Mail Division of Clinical Immunology and Allergy, Department of Medicine, St. Michael’s Hospital, University of Toronto, Toronto, Canada
Food allergy, Oatmeal allergy, Psocid


Occasionally, a seemingly straightforward history of food-induced anaphylaxis may prove to be misleading.  Both patients and their physicians have a tendency to attribute the cause of an allergic reaction to the most conspicuous ingredient that had been ingested while overlooking less likely causes.  Here, we describe a patient whose history pointed to oatmeal allergy, but skin prick tests to oats and serologic testing for oat-specific IgE were negative. Ultimately, we found that the oatmeal had been contaminated with an allergenic insect, Psocid of the order Psocoptera.


1. Soller L, Ben-Shoshan M, Harrington DW, Fragapane J, et al. Overall prevalence of self-reported food allergy in Canada. Vol. 130, The Journal of allergy and clinical immunology. United States; 2012. p. 986–8.
2. Warren CM, Gupta RS, Smith BM, Davis MM, Jiang J, Blumenstock JA, et al. Prevalence and Severity of Food Allergies Among US Adults. JAMA Netw Open. 2019;2(1):e185630.
3. Boyce JA, Assa’ad A, Burks AW, Jones SM, Sampson HA, Wood RA, et al. Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol. 2010 Dec;126(6 Suppl):S1-58.
4. Phillips TW, Throne JE. Biorational approaches to managing stored-product insects. Annu Rev Entomol. 2010;55:375–97.
5. Athanassiou CG, Arthur FH, Opit GP, Throne JE. Insecticidal effect of diatomaceous earth against three species of stored-product psocids on maize, rice, and wheat. J Econ Entomol. 2009 Aug;102(4):1673–80.
6. Obr S. Psocoptera of food-processing plants and storages, dwellings and collections of natural objects in Czechoslovakia. Acta Entomol Bohemoslov. 1978;75:226–42.
7. Turner BD. poscelis bostrychophila (Psocoptera: Liposcelididae), a stored-product pest in the UK. Int J Pest Manag. 1994;40:179–90.
8. Schroeckenstein DC, Meier-Davis S BR. Occupational sensitivity to Tenebrio molitor Linnaeus(yellow mealworm). Allergy Clin Immunol. 1990;86(2):182–8.
9. Masaki K, Fukunaga K, Kawakami Y, Haque R. Rare presentation of anaphylaxis: pancake syndrome. BMJ Case Reports CP [Internet]. 2019;12(3). Available from:
10. Ishibashi O, Sakuragi K, Fukutomi Y, Kawakami Y, Kamata Y, Sakurai M, et al. Lip b 1 is a novel allergenic protein isolated from the booklouse, Liposcelis bostrychophila. Allergy. 2017 Jun;72(6):918–26.
11. Patil MP, Niphadkar P V, Bapat MM. Psocoptera spp. (book louse): a new major household allergen in
Mumbai. Ann Allergy Asthma Immunol. 2001 Aug;87(2):151–5.
12. Fukutomi Y, Kawakami Y, Taniguchi M, Saito A, Fukuda A, Yasueda H, et al. Allergenicity and cross-reactivity of booklice (Liposcelis bostrichophila): a common household insect pest in Japan. Int Arch Allergy Immunol. 2012;157(4):339–48.
13. Jakubas-Zawalska J, Asman M SK. Sensitization to the storage mites Lepidoglyphus destructor and Tyrophagus putrescentiae (Acari, Sarcoptiformes, Astigmatina) in a suburban population in Southern Poland. Ann Parasitol. 2017;63(3):183–8.
How to Cite
Babaei D, Vadas P. Anaphylaxis to Oatmeal and Psocid Crisps. Iran J Allergy Asthma Immunol. 19(2):200-202.
Case Report(s)