Is nausea a symptom of Oral Allergy Syndrome (OAS)?

From the Guidelines

Nausea can be a symptom of food allergy, which includes Oral Allergy Syndrome (OAS), although it is not typically the primary symptom. According to a study published in the Mayo Clinic Proceedings in 2013 1, food allergy diagnosis requires documentation of a clinical history of a food allergic reaction, and symptoms can range from mild to severe. Mild symptoms may include a few hives, mild nausea/discomfort, while severe symptoms can be life-threatening.

Key Points to Consider

• The study defines food allergy as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a specific food 1.
• Symptoms of food allergy, including OAS, typically present within minutes to hours after ingestion 1.
• Nausea is mentioned as a possible mild symptom that may occur after ingestion of a specific food, alongside other symptoms like hives or discomfort 1.
• It's essential to differentiate between food allergy and food intolerance, as the latter is not immune-mediated and occurs due to pharmacologic, toxic, or metabolic properties of the food or the host 1.

Clinical Implications

Given the information from the study 1, if someone experiences nausea after eating certain foods, it could be related to a food allergy, including OAS, or another condition. It is crucial for individuals experiencing persistent or severe symptoms to consult a healthcare provider for proper evaluation and diagnosis. The provider may recommend tests such as food-specific IgE tests and/or skin prick tests to diagnose a food allergy 1. Management strategies include avoiding trigger foods, nutritional monitoring, and in some cases, prescribing antihistamines for mild reactions or an epinephrine autoinjector for severe reactions 1.

From the Research

Symptoms of Oral Allergy Syndrome

• The symptoms of Oral Allergy Syndrome (OAS) include itching and swelling of the lips, palate, and tongue, usually after consuming fresh fruits and vegetables 2, 3, 4, 5.
• Pruritus of the oral mucosa and, in particular, the posterior tongue, is also a common symptom of OAS 4.
• While the majority of those with OAS will experience mild symptoms, some individuals may be at risk of anaphylaxis, especially with the consumption of concentrated or unusual forms of plant food allergens 6.

Gastrointestinal Symptoms

• Nausea is not explicitly mentioned as a symptom of OAS in the provided studies 2, 3, 6, 4, 5.
• The symptoms of OAS are typically limited to the oral cavity, with itching, swelling, and pruritus being the most common complaints 2, 3, 4, 5.

Diagnosis and Management

• Diagnosis of OAS is primarily based on the patient's history, and confirmed by skin tests, in vitro tests, and oral provocation tests 2.
• Management of OAS includes avoiding or thermal processing of fruit and vegetables known to trigger a reaction, and antihistamine medications 2, 3, 4, 5.