From the Guidelines
Fresh grapes are unlikely to cause an anaphylactic reaction in individuals with moderate persistent asthma, but having asthma increases the risk of more severe allergic reactions if they do occur. Anaphylaxis from grapes is relatively rare and typically occurs in people with specific grape allergies rather than as a direct result of having asthma 1. According to the 2020 practice parameter update on anaphylaxis, risk factors for severe anaphylaxis include cardiovascular disease, asthma, older age, and additional coexisting, comorbid conditions 1.
The mechanism of anaphylaxis involves IgE binding and cross-linking of the high affinity IgE receptor (FcεRI) on the surface of mast cells and basophils, leading to the release of histamine and other chemicals that cause allergic symptoms 1. If you have moderate persistent asthma and suspect a grape allergy, you should consult with an allergist for proper testing. Signs of an anaphylactic reaction include difficulty breathing, swelling of the throat or tongue, hives, rapid heartbeat, dizziness, and a drop in blood pressure.
If you experience these symptoms after eating grapes, use your epinephrine auto-injector (such as EpiPen) if prescribed, and seek emergency medical attention immediately 1. The 2024 American Heart Association and American Red Cross guidelines for first aid recommend intramuscular epinephrine as the mainstay of immediate treatment for anaphylaxis 1. It's essential to note that having asthma and food allergies are separate conditions, though they can coexist and potentially exacerbate each other.
Key points to consider:
- Fresh grapes can trigger an anaphylactic reaction in individuals with specific grape allergies
- Having asthma increases the risk of more severe allergic reactions
- Anaphylaxis is a life-threatening, systemic allergic reaction that requires immediate treatment with epinephrine
- Consult an allergist for proper testing if you suspect a grape allergy
- Use an epinephrine auto-injector and seek emergency medical attention if you experience symptoms of anaphylaxis after eating grapes 1.
From the Research
Anaphylactic Reaction to Fresh Grapes in Moderate Persistent Asthma
- Fresh grapes can cause anaphylactic reactions in some individuals, as reported in several studies 2, 3, 4.
- These reactions can be severe and life-threatening, with symptoms including generalized urticaria, facial/oropharyngeal angioedema, and dizziness 2, 3.
- The allergens responsible for these reactions have been identified as grape lipid transfer protein (LTP; Vit v 1), an endochitinase, and a thaumatin-like protein (TLP) 5.
- However, LTP is considered the major grape allergen, and its cross-reactivity with other LTP-containing plant foods may contribute to clinical sensitivities 5.
Association with Moderate Persistent Asthma
- While there is no direct evidence linking fresh grape consumption to anaphylactic reactions specifically in individuals with moderate persistent asthma, the studies suggest that grape allergy can cause severe reactions in sensitized individuals, regardless of their asthma status 2, 6, 3, 4.
- It is essential to note that patients with grape allergy often have a history of atopy and may be sensitized to other foods and pollen, which can increase the risk of anaphylactic reactions 6, 4, 5.
Cosensitization to Other Foods
- Studies have shown that individuals with grape allergy often have cosensitization to other foods, such as apples, peaches, cherries, and nuts 6, 4.
- This cosensitization may be due to the presence of similar allergens, such as LTP, in these foods, and can increase the risk of anaphylactic reactions in sensitized individuals 5.