Reactions to multiple foods due to oral allergy syndrome rather than food allergy

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

A 31-year-old Caucasian male is here for evaluation of reported allergies to multiple foods. He had allergy symptoms after eating soy and almonds as a child and he has avoided them ever since. He reports increasing reactions to multiple foods during the last 3-4 years, especially in the last 6 months. The reactions consist mostly of oral itching and "unusual sensation" inside his mouth almost immediately after consuming a wide range of foods including apple, peach, apricot, hazelnut, carrot, banana, cucumber, watermelon and zucchini. He has no issues whatsoever when he consumes the same food in a cooked form. He does not report any wheezing, shortness of breath, abdominal pain or any other systemic symptoms when he consumes those foods and no urticaria either. He has a history of allergic rhinitis with multiple sensitizations to different types of allergens and he had received immunotherapy for less than 2 years, approximately 4-5 years ago. He remembers that skin prick tests were positive for cat, dust mites and dog. He is very active, and rides a bicycle regularly without any respiratory symptoms.

Past medical history (PMH)

Allergic rhinitis, received immunotherapy for less than 2 years, approximately 4-5 years ago.

Medications

None.

Social history and family history

Unremarkable.

Physical Examination

HEENT exam showed pale boggy turbinates on both sides. The rest of the physical examination was unremarkable.

What is the most likely diagnosis?

- Oral allergy syndrome
- Food allergy

What tests would you suggest?

- Skin prick testing
- ImmunoCAP for specific IgEs

What happened?

The skin prick testing result was quite remarkable with large positive reactions to multiple aeroallergens and in fact, those reactions were larger than the histamine reaction. The positive reactions were to cat, dust mite, tree mix, birch mix, grass mix, Timothy grass, rye grass, ragweed mix, and weed mix.

This is a patient with allergic rhinitis with multiple sensitizations to different types of allergens and cross reactivity when consuming certain foods, which is typical of the diagnosis of oral allergy syndrome. There is a known cross reactivity in patients who are sensitized to birch, when they consume apple, peach, apricot, hazelnut, potato, and celery in raw form. There is a known cross reactivity in patients who are sensitized to ragweed who consume banana, cantaloupe, watermelon, zucchini and cucumber. Our patient is sensitized to both birch and ragweed. Also, he is sensitized to weed mix as well, which confers additional and different cross reactivity. It is typical for oral allergy syndrome that the patients react when they consume raw foods, but not cooked foods.

What treatment would you recommend?

The patient was advised to avoid the use of raw vegetables which trigger symptoms. There is a slight risk of systemic reaction which in the range of 1% to 10% in patients who have oral allergy syndrome when they consume the offending foods in raw form. He was advised to have an Epi-Pen at all times if a systemic reaction develops. We also recommended that he should take an oral antihistamine consisting of cetirizine 10 mg daily, and Singulair 10 mg p.o. daily. The treatment with antihistamine may alleviate some of his local reactions when he consumes the triggering foods. He has significant allergic rhinitis and we recommended a steroid nose spray to be used twice a day. We also ordered specific IgE blood testing to almonds, soy, walnut, apple and potato to check the levels of the specific IgE to foods that triggered more significant reactions in the past.

Final diagnosis

Oral allergy syndrome.

References

Profilin may be a pan-allergen among plants that crossreacts between pollen, fruits, vegetables and latex http://goo.gl/ZUPRQ

Cross Reactions Among Foods (PDF).

Related reading

Flavored Coffee May Trigger Seasonal Allergies - due to oral allergy syndrome. Fox News, 2011.
Oral symptoms from the ingestion of food in a patient with allergic rhinitis - AAAAI Ask the Expert, 2011.
In birch-apple syndrome (oral allergy syndrome), eating apple does not affect the respiratory tract. Annals of Allergy, Asthma and Immunology, 2011.

Published: 07/03/2010
Updated: 12/12/2011