Fruits and vegetables are high in nutrients but can cause an allergic reaction in and around the mouth in some people. A citrus allergy rash and other types of fruit allergy skin rashes can result when antibodies recognize proteins that are similar to those in allergenic pollen.
Eating raw fruits and vegetables can cause an allergic reaction in people who are allergic to certain types of pollen.
Oral Allergy Syndrome
Many allergies — especially food allergies — present in young childhood, or even infancy. Most children tend to outgrow food allergies by adulthood, but some allergies do not appear until later in childhood or adulthood. Allergies to pollen and foods related to pollen generally start after age 3.
Oral allergy syndrome is triggered by pollen and raw fruits and vegetables. According to the American College of Allergy, Asthma and Immunology, people with oral allergy syndrome may be allergic to multiple raw fruits or vegetables that come from related plants due to similarities in the pollen. The allergy often includes tree pollen from trees in the same botanical family as the fruits and vegetables.
Cross-reactivity: Pollen Allergy Triggers
A November 2015 review published in Journal of Allergy states that proteins in pollen trigger an immune response in people who are allergic to those types of pollen. The immune system makes antibodies to combat the pollen proteins, which causes an allergic reaction. People who have hay fever from pollen can also experience oral allergy symptoms.
Once an individual becomes sensitized to an allergenic airborne pollen, he or she can become allergic to a cross-reactive allergen in a related type of produce. Proteins that are present in raw fruits and vegetables have similar structures to the allergenic proteins in pollen and illicit an immune response when these foods are consumed.
According to the American College of Allergy, Asthma and Immunology, apples, cherries, peaches, pears, plums, carrots and celery belong to the same allergen family as birch tree pollen. Grass pollen allergens also include oranges, melons, peaches, tomatoes and celery. In addition to causing hay fever, ragweed pollen is also associated with oral allergies for bananas, melons, cucumber and zucchini.
Symptoms of Oral Allergy Syndrome
The symptoms of oral allergy syndrome are generally confined to the areas in and around the mouth such as the tongue, lips, throat and other surfaces within the oral cavity. Eating raw fruits or vegetables that trigger an immune response can cause swelling, redness and itchiness on the skin and mucosal tissues. Scratchiness or swelling in the throat can also occur.
A fruit allergy skin rash is usually limited to the area around the mouth and face but can spread to other areas in some individuals. While the symptoms from eating raw fruits may be unpleasant, they aren't typically serious and dissipate quickly after eating. Hives that result from a fruit allergy be helped by supplementing with vitamins C and D or by eating foods rich in these nutrients.
Many fruits and vegetables that cause an allergic reaction when eaten raw can be safely and comfortably consumed when they are cooked. The ACAAI states that cooking process changes the proteins in ways them make them unrecognizable to the antibodies. Fruits and vegetables lose some of their nutrients when they are cooked, but the loss can be minimized by steaming or microwave cooking instead of boiling or baking them.
Read more: Causes of a Full Body Rash
Latex, Fruit and Vegetable Allergy
Natural latex is a product of a tropical tree and is a component in the manufacture of disposable gloves, medical tubing, sneakers, balloons, elastic waistbands, sporting equipment and baby items like pacifiers. A latex allergy can cause symptoms of nasal congestion, difficulty breathing and anaphylaxis in extreme cases.
A latex reaction may also cause itchy, red, or swollen skin and hives on contact or simply from breathing in tiny particles in the air. According to an April 2016 study published in Advances in Dermatology and Allergology, about 30 percent of people with a latex allergy also have a sensitivity to apples, which can cause an apple allergy skin rash in some patients. A latex allergy can also cause a cross-reactive allergy to other fruits and vegetables such as apples, kiwis, melons, bananas, avocados or celery.
Citrus Allergy Symptoms and Treatment
A January 2013 study published in the journal PLOS One found that among the 72 people tested, 39 percent of patients age 4 to 22 with pollen allergies were also sensitive to citrus fruits, especially those allergic to grass pollen. People with this allergy experience a reaction when exposed to fresh fruits such as pulp from oranges, clementines and lemons. Symptoms of citrus allergy are consistent with oral allergy syndrome, including skin redness.
Citrus allergy rash treatment is based on avoidance, as food allergies can't be effectively treated. People with a citrus allergy can usually avoid an allergic reaction by limiting consumption to juices, pulp and zests that have been cooked, such as marmalade or pasteurized juices.
Read More: How to Get Rid of an Allergic Reaction Rash
- American College of Allergy, Asthma and Immunology: “Oral Allergy Syndrome”
- Journal of Allergy: “Oral Allergy Syndrome- An Update for Stomatologists”
- American of Allergy, Asthma and Immunology: "Latex Allergy"
- Advances in Dermatology and Allergology: “Differentiating of cross-reactions in patients with latex allergy with the use of ISAC test”
- PLOS One: “Citrus Allergy From Pollen to Clinical Symptoms”
- Children's Hospital of Philadelphia: "Top 8 Food Allergies in Kids and What Parents Need to Know"