It's just a dust mite allergy, why did I go into shock after eating pancakes? Understanding pancake syndrome

Case:

A 15-year-old girl soon developed symptoms such as flushing, rash, pharyngeal discomfort, dyspnea, and wheezing after eating pancakes made from mixed wheat flour. The mixed wheat flour (wheat flour, potato flour, sea salt, beef flour) was stored in a plastic container and placed in a humid environment for several weeks. The pancakes were served with eggs, shrimp, and leeks. The child had no reaction to any of these foods in the past, and other family members who ate them at the same time had no discomfort. The patient had suffered from asthma and atopic dermatitis since the age of 3. The results of allergen testing showed that the total IgE level was significantly increased, and the dust mite-specific IgE was positive (household dust mite level 6, dust mite level 6, putrescent tyrophagoides mite level 3, lepidophilus mites level 3, and rough foot powder mite level 3). The specific IgE of other related foods, wheat, egg yolk, egg white, shrimp, beef, and potatoes were all level 0. Under the microscope, a large number of live mites were seen in the mixed wheat flour. Therefore, this severe allergic reaction was caused by eating wheat flour contaminated by dust mites, and the patient was diagnosed with "pancake syndrome." The case comes from the literature Seitaro Senba et al. Respiratory Medicine Case Reports 30 (2020) 101026

What is Pancake Syndrome?

Pancake syndrome is a severe, life-threatening allergic reaction in individuals who are allergic to dust mites after eating pancakes made from flour contaminated by dust mites. It is also called oral mite anaphylaxis (OMA).

What is the trigger?

The most common cause is food made from wheat flour contaminated by dust mites. Although it is called pancake syndrome, other foods such as donuts, pizza base, Japanese pancakes (such as Okonomiyaki), scones, sponge cakes, etc. can all be causes. Compared with fresh flour, flour that has been stored for a long time is more likely to induce OMA. Both dust mites and storage mites can induce OMA, including: house dust mites, dust mites, tropical clawless mites, clawless mites, oval flour mites, cotton wrinkled skin mites, lepidophilous mites, and putrescent tyrophagous mites. Since most of them are caused by heated foods, it is considered that the heat-resistant dust mite allergen components may induce OMA.

What are the common clinical manifestations?

A severe allergic reaction that occurs 10-45 minutes after eating food contaminated by dust mites. Common symptoms include urticaria, facial/laryngeal edema, coughing, wheezing, and dyspnea. It should be noted that about 75% of reactions are severe. Two cases of death due to OMA have been reported in the literature.

What are the risk factors and susceptible populations?

1. Most cases come from tropical and subtropical regions, but there are also cases from temperate regions, such as Japan, Spain, etc. High temperature (>27°C) and high relative humidity (>70%) are the best environment for the reproduction of dust mites in food.

2. People who are allergic to dust mites;

3. Combined with respiratory allergic diseases such as rhinitis, asthma, etc.;

4. Allergy to aspirin/NSAIDs;

5. Eating food contaminated with dust mites.

OMA diagnostic criteria

1. A rapid and severe allergic reaction occurs after eating food made from wheat flour;

2. History of allergic rhinitis/asthma;

3. Internal or external allergen testing indicates dust mite allergy;

4. Positive skin test of contaminated flour extract;

5. Negative skin test for wheat allergen or uncontaminated flour extract;

6. Can tolerate food made from uncontaminated flour;

7. Dust mites can be seen under a microscope in flour;

8. Detect dust mite allergen components in flour.

Precautions

1. Shorten the shelf life of flour in food stores.

2. Flour should be stored in the refrigerator for less than 6 weeks.

3. Store flour in a sealed glass container or plastic bottle.

4. Use an air purifier to improve air quality.

5. Cleaning and disinfection of furniture and floors.

6. Use miticides indoors and reduce contact with allergens.

7. Improve the cleanliness of the kitchen, pantry and cabinets.

OMA is a severe, life-threatening allergic reaction, most of which are severe cases, and there are currently reports of deaths. There is currently a lack of understanding and treatment of it in the clinic. When severe allergic reactions occur in individuals with dust mite allergy and are related to eating pasta, but all food-related allergens are negative, the diagnosis of OMA should be considered. Raising awareness and implementing preventive measures may be effective in reducing morbidity and mortality.

References:

1. Senba S, T Tsuji, R Kikuchi, et al., Oral mite anaphylaxis after ingestion of Korean pancake. Respir Med Case Rep, 2020. 30: 101026.

2. Sanchez-Borges M and E Fernandez-Caldas, Hidden allergens and oral mite anaphylaxis: the pancake syndrome revisited. Curr Opin Allergy Clin Immunol, 2015. 15: 337-343.

3. Sanchez-Borges M, R Suarez Chacon, A Capriles-Hulett, et al., Anaphylaxis from ingestion of mites: pancake anaphylaxis. J Allergy Clin Immunol, 2013. 131: 31-35.