An allergy is defined as the immune system reaction to a substance that’s not typically harmful coming in contact with or entering your body. These substances are called allergens and can include foods, pollen and grass, and chemicals.

Allergic reactions to fruit are commonly associated with oral allergy syndrome (OAS). It’s also known as pollen-food allergy.

OAS occurs from cross-reactivity. The immune system recognizes the similarity between pollen (a common allergen) and the proteins in raw fruits, vegetables, and tree nuts. That recognition triggers an allergic reaction in some people.

Here are the types of pollen and their related fruits that may trigger an OAS reaction:

  • Birch pollen: apple, apricot, cherry, kiwi, peach, pear, and plum.
  • Grass pollen: melon, orange
  • Ragweed pollen: banana, melon
  • Mugwort pollen: peach

OAS and fruit allergies can trigger symptoms that range from uncomfortable to severe and even life-threatening.

Common signs and symptoms include:

In some cases, a life-threatening reaction called anaphylaxis may occur. Seek emergency medical attention if you experience any of the following:

For some people, reaction to food isn’t a true allergy but rather a food intolerance. Because food allergies and food intolerances often have similar signs and symptoms, they can be mistaken for each other.

If think you might have one of these conditions, see your doctor for a diagnosis to identify the source of your discomfort.

Many factors can cause a food intolerance, such as:

  • irritable bowel syndrome (IBS)
  • lactose intolerance
  • non-celiac gluten sensitivity
  • food additives, such as sulfites used for preserving dried fruit
  • psychological factors

In regards to fruit, a food intolerance is often a sensitivity to chemicals that naturally occur in a specific fruit. Sometimes, it’s an inability to digest the natural sugar found in fruits (fructose).

If eating or coming in contact with a specific type of fruit causes a negative physical reaction, make an appointment with your doctor. They might recommend you see an allergist.

An allergist can offer a number of methods to make and confirm a diagnosis, including:

  • reviewing your symptoms and suspected triggers
  • reviewing your family history of allergies
  • performing a physical examination
  • using a skin prick test for a variety of fruits
  • analyzing your blood for immunoglobulin E (IgE), an allergy-related antibody
  • testing and measuring your reaction when you consume various fruits

If you have a physical reaction to fruit, make an appointment with your doctor or allergist. There are a variety of diagnostic tests they can perform to identify an allergy, OAS, or food intolerance.

Once a diagnosis has been made, your doctor or allergist can suggest treatment options and the best way to handle your symptoms in the future.