Anaphylaxis After Eating Dust Mites

A Look at Pancake Syndrome

Baker preparing ceramic bowls for baking bread
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Dust mites are a common cause of allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis. They're found in most places in the world, particularly in humid environments. Specifically, dust mites are most commonly found in bedding material, carpeting, and upholstered furniture, but may also contaminate foods made from wheat flour—although other cereal grains may also be contaminated with dust mites.

People allergic to dust mites have experienced anaphylaxis as a result of eating foods contaminated with dust mite particles. This syndrome has been given the name oral mite anaphylaxis (OMA), or pancake syndrome.

How Common is Pancake Syndrome?

It's unknown how common OMA is—as it probably goes unrecognized as a cause of a person’s anaphylaxis—although there are 135 case reports on the condition in medical literature as of May 31, 2012. OMA was first reported after people in Detroit and Philadelphia experienced anaphylaxis after eating beignets prepared from a beignet mix obtained in New Orleans. Since then, a number of cases have been reported in other parts of the world, including South America, Asia, Europe and Australia. Many other cases are not likely reported or are blamed on another condition, including allergic reactions to other components of a meal, most commonly wheat allergy.

OMA is most often reported in younger people who suffer from other allergic conditions, although it may occur in people of all ages, including children.


Symptoms of OMA typically occur within a few minutes to hours after eating a food contaminated with dust mites and include asthma symptoms, angioedema, and severe anaphylaxis.

Exercise-induced anaphylaxis as a result of eating pancakes contaminated with dust mites, followed by playing soccer, has also been reported.


People who are allergic to dust mites are at risk for OMA, although it's not clear why more people are not experiencing this condition, given how common dust mite allergy is—and how often flour is likely contaminated with the mites. In people reported to have experienced the pancake syndrome, nearly half (44%) had a history of allergy to non-steroidal anti-inflammatory drugs (NSAIDs). It has been proposed that the association between OMA and NSAID allergy could be explained by mite particles having an effect on the COX-1 enzyme, affecting leukotriene production, or another unknown cause.

Diagnosis and Treatment

The diagnosis of OMA is made on a clinical basis in a person experiencing anaphylaxis after eating a food found to be contaminated with dust mites. Of course, that person would have to be allergic to dust mites and not be allergic to any of the food allergens in the culprit food. A history of NSAID allergy would make the case for OMA more likely.

The treatment of anaphylaxis from the pancake syndrome would be the same as with other causes of anaphylaxis, although prevention of future episodes would be the goal for people with OMA.

Storing flour in the refrigerator in sealed plastic or glass containers would likely prevent the contamination of flour by dust mites, and therefore prevent OMA.


Sanchez-Borges M, Suarez Chacon R, Capriles-Hulett A, Caballo-Fonseca F, Fernandez-Caldas E. Anaphylaxis From Ingestion of Mites: Pancake Anaphylaxis. J Allergy Clin Immunol. 2013;131:31-5.