Allergic reactions to fruit and vegetables are usually mild and often just affect the mouth, causing itching, a rash, or blisters where the food touches the lips and mouth. This is called oral allergy syndrome. A number of people who react in this way to fruit or vegetables will also react to pollen from some trees and weeds. So, for example, people who are allergic to birch pollen are also likely to be allergic to apples. Another symptom may include slight swelling in the throat, making it feel like it is closing. The ability to breathe is still present though, so it is not fatal.
Other symptoms due to hypersensitivity
The symptoms may vary upon the person and the severity of the allergy and also the type of fruit, for example mango allergy was shown that they may go from symptoms such as hoarseness, dyspnoea and bronchitic rales (asthma) (Sareen and Shah). The length of the appearance of the symptoms tested by Saree and Shah were variable and ranged from 4 h  to 7 days . The appearance of symptoms may appear within a few minutes.
Different allergic fruits
There are many different types of fruits that people have been shown to react allergically such as mangoes and bananas. Some foods are clearly more allergenic than others. In adults, peanuts, tree nuts, finned fish, crustaceans, fruit, and vegetables account for 85% of the food-allergic reactions(O'Neil, Zanovec and Nickla). People suffering from allergies may suffer from a hypersensitivity to the allergic food, which is what causes the allergic reaction. Most fruit allergies are oral syndrome allergies because they are consumed but may also be an external allergy if the fruit touches the skin.
Skin prick testing is a common way of testing for an allergy. Other ways to test for allergies can be challenge testing, which consists in feeding a very small and measured amount of the allergen to the patient and monitor the reaction (O'Neil, Zanovec and Nickla). This should only be done by a doctor under surveillance.
Allergy or intolerance
An allergy is different from an intolerance. Food allergies and food intolerances should not be confused because they do not contain the same risks and are not diagnosed the same way. Allergies can be fatal after only a small consumption, while intolerance, although uncomfortable, are not as deadly. An intolerance may lead to a nutrient deficiency which could cause death if untreated but the intolerance itself is not enough to cause rapid death. Allergies, with their varying symptoms, could cause instantaneous death if there is inflammation in the throat and causes suffocation.
For those allergic to fruits, cooking may help reduce or eliminate the reaction to some fruits.
- Sareen and Shah. (2011). Hypersensitivity manifestations to the fruit mango. Asia Pacific Allergy. (44-49). Retrieved from http://www-ncbi-nlm-nih-gov.login.ezproxy.library.ualberta.ca/pmc/articles/PMC3206236/pdf/apa-1-43.pdf
- O'Neil, Zanovec and Nicklas. (2010). A Review of Food Allergy and Nutritional Considerations in the Food-Allergic Adult. American Journal of Lifestyle Medicine. (49-62). Retrieved from http://ajl.sagepub.com.login.ezproxy.library.ualberta.ca/content/5/1/49.full.pdf+html