Researchers describe case of funnel cake anaphylaxis linked to dust mites

PHOENIX — Researchers traced a case of anaphylaxis following ingestion of funnel cake to dust mites stored in flour in a case review presented as a poster at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

“Dust mites are one of the most prevalent environmental allergens associated with many atopic diseases such as asthma, allergic rhinitis and atopic dermatitis,” Jenny J. Lee, MD, of the division of allergy and clinical immunology at University of Michigan, said during her presentation.

Lee noted that the habitats of dust mites are not limited to beddings and furniture, as they can also grow in foods such as grain flour, cured meat or cheese.

“One way hypersensitivity to mites can manifest is oral mite anaphylaxis, also called ‘pancake syndrome,’ which is an anaphylactic reaction that develops after ingesting foods contaminated with mites that is mediated by mite-specific IgEs,” Lee said.

Lee presented a case that involved a female aged 14 years who had mild persistent asthma, allergic rhinitis and atopic dermatitis. Five minutes after eating funnel cake, she developed stridor and lip swelling, for which she was taken to the ED and given intramuscular epinephrine, IV diphenhydramine, IV ranitidine and IV methylprednisolone, leading to significant improvement in her respiratory symptoms.

“Her symptoms resolved in the emergency room and she was discharged home with epinephrine autoinjectors,” Lee said. “When she was seen in the allergy clinic, she denied history of anaphylaxis to any foods or medications in the past. She reported tolerating major ingredients of funnel cake, including wheat flour, eggs, dairy and caramel, and she denied having any other new exposures at the time of the reaction.”

Lee added that the patient mentioned having had itchy mouth after eating shrimp in the past.

Based on this history, researchers conducted skin prick testing for common environmental allergens and shellfish. The patient tested positive to multiple inhalant allergens, including dust mites and cockroach, but did not show any sensitivity to the shellfish tested.

“This skin test result is consistent with sensitivity to dust mites,” Lee said. “She had an anaphylactic reaction to funnel cake and given her history of tolerating common ingredients found in funnel cake, her reaction was thought to be secondary to ingestion of the dust mites stored in grain flour.”

Flour stored in a humid and warm environment presents favorable conditions for dust mites to grow and reproduce, Lee said, adding that most cases of dust mite anaphylaxis originate from areas with tropical weather.

Also, researchers surmised that the patient’s oral itching symptoms following eating shrimp was due to cross-reactivity of allergens between shellfish, dust mites and cockroaches.

“Crustacean shellfish, dust mites and cockroaches are all part of the arthropod family and share a similar amino acid sequence structure called tropomyosin,” Lee said. “Studies show up to 5% to 15% of mite-allergic cases can be sensitized to cockroaches and shellfish.”

Lee added that this oral itching after eating shrimp can be considered a type of oral allergy syndrome.

“Unlike pollen-food allergy syndrome, where cooked fruits and vegetables are well-tolerated, mite allergen-containing foods can still induce allergy symptoms even after it is fully cooked, as it is thermoresistant,” Lee said, adding that the funnel cake would be an example of this.