Cultivated wheat
Summary
Triticum aestivum is a member of the Poaceae family that produces wheat aeroallergens responsible for pollen allergy and occupational respiratory allergy to cereal flour, known as ‘Baker’s asthma’. Sensitization to cultivated wheat causes rhinitis and asthma and is prevalent among patients with respiratory allergies who are multi-sensitized to aeroallergens.
Epidemiology
Worldwide distribution
Sensitization to cultivated wheat is common in people with respiratory allergies who are multi-sensitized to aeroallergens. Sensitization is thought to affect males more than females and a wide range of sensitization frequency (17.7–60.8%) has been reported in studies; cross-reactivity with timothy grass may account for the high percentage of sensitization levels seen.
Baker's asthma, an occupational respiratory allergy to cereal flour, affects up to 9% of bakers; it is the leading cause of occupational asthma in France, and the second highest in the UK. Among bakers with occupational asthma, 47% are sensitized to the T. aestivum allergen 25 (Tri a 25).
Patients with baker's asthma usually ingest wheat products without issue, although in a study of children with grass pollen allergy, up to 65% had false positive results for wheat extract.
Risk factors
Living or working close to T. aestivum cultivation.
Occupations that involve working with cereal flours, such as bakers, farmers, confectioners, flour millers, and food processors.
Route Of Exposure
Main
Inhalation.
Secondary
Contact.
Clinical Relevance
Symptoms of cultivated wheat sensitization include rhinitis, conjunctivitis, urticaria, asthma and, rarely, systemic anaphylaxis.
Cross-Reactivity
Cross-reactivity has been reported between wild grass and cereal pollen; cultivated maize, rice, wheat, rye, barley and oats, can induce symptoms in individuals sensitized to grass pollen. Cross-reactivity with common grass species (Anthoxanthum odoratum, Dactylis glomerata, Lolium perenne, Poapratensis and Phleum pratense) has been shown.
The Zea mays allergen 25 (Zea m 25) exhibits high IgE cross-reactivity with the T. aestivum allergen 25 (Tri a 25) while rice pollen shows weak cross-reactivity with wheat.
Profilin is recognized as a cross-reactive allergen in patients with baker’s asthma, food and pollen allergy.
References
- Damialis A, Konstantinou GN. Cereal pollen sensitisation in pollen allergic patients: to treat or not to treat? Eur Ann Allergy Clin Immunol. 2011;43(2):36-44.
- Lukow OM, McVetty PBE. GRAIN PRODUCTION AND CONSUMPTION | Cereal Grains in North America. In: Wrigley C, editor. Encyclopedia of Grain Science. Oxford: Elsevier; 2004. p. 94-106.
- CABI. Triticum aestivum (wheat) Wallingford, UK2021 [cited 2022 18.01.22]. Available from: https://www.cabi.org/isc/datasheet/55204.
- Ramirez DA, Jr., Bahna SL. Food hypersensitivity by inhalation. Clin Mol Allergy. 2009;7:4.
- Weichel M, Glaser AG, Ballmer-Weber BK, Schmid-Grendelmeier P, Crameri R. Wheat and maize thioredoxins: a novel cross-reactive cereal allergen family related to baker's asthma. J Allergy Clin Immunol. 2006;117(3):676-81.
- Czaja-Bulsa G, Bulsa M. What Do We Know Now about IgE-Mediated Wheat Allergy in Children? Nutrients. 2017;9(1).
- Constantin C, Quirce S, Poorafshar M, Touraev A, Niggemann B, Mari A, et al. Micro-arrayed wheat seed and grass pollen allergens for component-resolved diagnosis. Allergy. 2009;64(7):1030-7.
- Allergome.org. Triticum aestivum pollen 2021 [cited 2022 18.01.22]. Available from: http://www.allergome.org/script/search_step2.php.
- Hrabina M, Jain K, Gouyon B, editors. Cros“ reactivity between pollen allergens from common Pooideae grasses and cultivated cereals2008.