Food ingestion anaphylaxis caused by mites is a newly described syndrome, as detailed by the World Allergy Organization in this month’s Journal of Allergy and Clinical Immunology. Until recently mite allergy was best recognized as a major cause for allergic rhinitis and asthma via the inhalation of the microscopic mites. Millions of allergy sufferers actually receive allergy shots for this mite allergy. Over the years occasional case reports would appear in the medical literature about airway anaphylaxis; that is, sudden and severe closure of the airways due to an inordinate inhalational dose of mite, such as from spilling a vacuum cleaner bag. But until recently, there had never been reports of anaphylaxis from the ingestion of mites.
The new syndrome has been dubbed oral mite anaphylaxis (OMA), or also “pancake syndrome,” because the primary source of ingested mites is from wheat flour contaminated with mites — and for some reason, this occurs most often in pancake mix. The syndrome occurs primarily in warm, tropical or sub-tropical locations where temperature and humidity favor the proliferation of mites in certain foods. In some cases the wheat itself was mistakenly assumed to cause the reaction because the presence of mites was not initially suspected. Also, the patient may live in a northern clime, but have a reaction from wheat or flour mix produced in a tropical area.
Unfortunately, cooking does not inactivate the mites in terms of allergenicity. Other common foods that have been implicated are pizza dough, beignets, polenta, grits and scones.