All you need to know about the house dust mite
For the Curious

How guilty is the mite? Research points towards inflammatory responses beyond allergy

Evidence is mounting that a form of severe oral allergic reaction associated with mites may also have a non-allergic element entwined as a trigger. The reaction is linked to an established atopic dust mite allergy; ingestion of foods made with mite-infested flour; and a known hypersensitivity to aspirin or non-steroidal anti-inflammatory drugs (NSAIDS).
For over twenty years scientists have investigated a relatively rare but severe oral allergic reaction linked to patients who have a combination of three 'events'. The first is an established atopic dust mite allergy, two they have just eaten foods made with mite-infested flour, and three, have a known hypersensitivity to aspirin or NSAIDS. These three components are associated with the oral anaphylactic reaction known as Pancake Syndrome. Now, a recently published review paper has compiled information from over 102 cases and 15 clinical studies to argue that the phenomenon may not be wholly based in allergy, but also have genetic and or innate inflammatory origins.

Thanks to the work of researchers the association of mite hypersensitivity with aspirin/NSAIDS intolerance has been clinically confirmed. However, what remains to be described is the connection between atopic allergy and non-allergic pathways. The paper names the foods implicated; the dust mite species associated with 'Pancake Syndrome'; describes the possible innate reactions involved; and identifies genetic factors that could be involved.

Foods (noted to date) Beignets, pizza dough, okonomi-yaki, polenta, flour-coated fish, scones and pancake mix. Pancakes are the most common food implicated in the reaction, hence the name.

Some of the allergic and innate immune responses mentioned are:

  1. Allergy Specific IgE leading to immediate hypersensitivity; Peptidases leading to tissue damage and increased allergen absorption; Role of Der p1, Der p2 and Der p7 in allergy.
  2. Innate immunity Activation of APCs, (cytokine production); Cyclooxygenase modulation leading to increased leukotriene production; Dectin 2-glycan interaction by Der p2 leading to increased leukotriene production.
Dust mites implicated in Pancake Syndrome are: Dermatophagoides farinae, Dermatophagoides pteronyssinus, (house dust mites) Tyrophagus spp., Suidasia spp., Blomia freemani, and Aleuroglypus ovatus (storage mites)

The author's abstract ends with: 'The association of mite hypersensitivity with aspirin NSAIDS intolerance has been confirmed and provides additional clues to various non-allergic pathways that may contribute to the acute and chronic inflammatory process observed in atopic, mite-allergic, individuals. The clinical relevance of these observations is presently under investigation'.

Perhaps under investigation is the possibility that inhibition of COX-1 isoenzyme, as seen in aspirin/NSAIDS hyper-reactivity, and the presence of COX-1 inhibitory substances in commercial house dust mite allergen extracts, may contribute to Pancake Syndrome. The possibility is discussed in this paper.


References

'Mite-induced inflammation: More than allergy', Sanchez-Borges M, Fernandez-Caldas E, Capriles-Hulett A, Caballero-Fonseca F, 'Allergy Rhinol' (Providence). 2012; 3 (1) e25-e29.

'Inhibition of human cyclooxygenase-1 by Dermatophagoides allergenic extracts'. Sanchez-Borges M, Owellet M, Percival M, et al, 'J. Allergy Clin. Immunol.', 115:S51, 2005