Oral Allergy Syndrome Management

Introduction to Oral Allergy Syndrome

• Oral allergy syndrome (OAS) occurs due to cross-reactivity between pollen allergens and structurally similar proteins found in fruits and vegetables, with some allergenic proteins being only partially denatured during cooking, leaving enough intact allergen to trigger symptoms 1
• The National Institute of Allergy and Infectious Diseases (NIAID) guidelines distinguish between true food allergy (potentially life-threatening) and OAS (typically milder), with most OAS reactions being mild and limited to the oral cavity 2

Diagnosis and Symptoms

• An allergist can perform skin prick tests (SPT) to identify sensitization to specific pollens and foods, serum-specific IgE testing to measure antibodies to suspected allergens, and oral food challenges under medical supervision to confirm allergies 1
• A medically supervised oral food challenge can help determine if individuals can safely consume foods prepared in different ways, and comprehensive testing by an allergist can identify specific allergens and cross-reactivities 1

Management of OAS

• For patients with a history of more severe reactions, the American Academy of Allergy, Asthma, and Immunology recommends avoiding raw trigger foods completely and reintroducing foods under physician supervision through oral food challenges, with placement of secure peripheral intravenous access before oral food challenges may be warranted in patients with past severe reactions 3
• For patients with a history of only mild oral symptoms, home reintroduction of cooked/processed forms may be reasonable, but for patients with any history of systemic reactions, reintroduction should occur under medical supervision, as recommended by the American Academy of Allergy, Asthma, and Immunology 3
• The decision to reintroduce foods at home should be a shared decision between providers and patients, accounting for access to emergency care, caregiver comfort, nature of the trigger food, and severity of past reactions, according to the American Academy of Allergy, Asthma, and Immunology 3
• The American Academy of Allergy, Asthma, and Immunology recommends taking H1 antihistamines before consuming trigger foods, and for isolated mild symptoms, antihistamines alone are appropriate, as stated by the Journal of Allergy and Clinical Immunology 4
• Antihistamines can be taken before potential exposure to trigger foods, as recommended by the American College of Allergy, Asthma, and Immunology 5
• Cooked or processed forms of the food, including artificial flavors, are usually tolerated by patients with OAS, according to the American College of Allergy, Asthma, and Immunology 5
• The allergenic proteins in fruits, including apples, become denatured during processing methods such as heating, pasteurization, and commercial processing, which reduces their allergenic potential, as supported by the Journal of Allergy and Clinical Immunology 1
• Commercially pasteurized fruit juices, such as apple juice, are safer than freshly pressed, unpasteurized juices for individuals with OAS, as stated in a 2017 publication in Pediatrics 6

Special Considerations

• Patients with OAS should seek allergy re-testing if their symptoms have changed or worsened over time, or if they want to identify specific trigger foods to better manage their condition, as suggested by the American Academy of Allergy, Asthma, and Immunology 5
• Unnecessary dietary restrictions can lead to weight loss, poor growth, calcium deficiency, hypovitaminosis, and compromised nutritional status, particularly concerning in patients with eating disorders, according to the American Academy of Dermatology 2, 7
• Excessively restrictive diets, especially in patients with eating disorders, can lead to serious nutritional deficiencies, and multiple dietary restrictions should only be implemented with documented, clinically relevant food allergies, as recommended by the American Academy of Dermatology 2, 7
• Avoiding artificial flavors when one only reacts to fresh fruits unnecessarily restricts diet and may impact quality of life, as noted by the American College of Allergy, Asthma, and Immunology 5
• The NIAID guidelines strongly recommend nutritional counseling and regular growth monitoring for all individuals with food allergies, especially critical for patients with eating disorders 2
• Epinephrine auto-injectors are not typically required for isolated OAS reactions unless there's a history of systemic reactions, as recommended by the American Academy of Allergy, Asthma, and Immunology 8
• Confusing OAS with systemic food allergy can lead to unnecessary treatment, as OAS rarely causes systemic reactions, while true food allergies can be life-threatening, as warned by the American Academy of Allergy, Asthma, and Immunology 1
• Until a patient can see an allergist, they should avoid raw fruits and vegetables that trigger symptoms, try cooking or processing trigger foods, and consider taking antihistamines before potential exposure if recommended by their doctor 5