This is why some foods make your mouth itchy
For some people, these seasonal favorite fruits can cause irritation and swelling in the mouth and throat. If you have ever experienced an itchy or swollen mouth after consuming seasonal fruits and vegetables, you might have a pollen-related food allergy.
Oral allergy syndrome (OAS), also known as pollen-related food allergy (PRFA) and pollen fruit syndrome (PFS), is a common food allergy found in individuals who are also allergic to pollen.
About 90% of individuals who are allergic to pollens like birch experience allergic reactions to pollen-related foods. Why is this? It turns out the proteins in produce such as apples, cherries, carrots and celery biologically resemble the pollen in birch. Dr. Javeed Akhter, a pediatric pulmonologist at Advocate Christ Medical Center in Oak Lawn, Ill., says “the symptoms of oral allergy syndrome can get worse during the season when the pollen levels are higher.”
When consumed, foods that trigger OAS can cause itchiness and swelling in the mouth and throat. Symptoms are rarely life-threatening and typically persist for 30 minutes or less. Unfortunately, regular allergy medication does not typically work for pollen-related food allergies.
Dr. Akhter says this is because pollen-related food allergies cause “a ‘mast cell’ mediated reaction. Unlike lungs, nose, eyes and gut,” he says, “there are no good strategies to stabilize mast cells in the oropharynx,” which lies at the back of the throat.
About 2% of individuals who experience OAS have reactions that affect more than the oral cavity. These patients may carry an epipen with them, Dr. Akhter says.
Avoiding trigger foods or suffering through allergic reactions may not be the only options, however. A study shows that OAS could be effectively treated by oral immunotherapy or sublingual immunotherapy. Yet, “immunotherapy as a treatment for pollen-related food allergies is still in the experimental stage,” Dr. Akhter says. Recently, the Food and Drug Administration approved oral immunotherapy for peanut allergies.
In a study comprising 92 individuals, regular exposure to trigger food proteins over an eight- to 11-month period through oral and under-the-tongue immunotherapy resulted in up to 81% of allergic individuals becoming tolerant to pollen-related trigger foods. When repeatedly exposed to triggering proteins, the immune system slowly learns that those foods are not a threat to the body and allergic reactions become less frequent. Continued immunotherapy may be necessary to maintain tolerance, however, as many individuals experienced a returned sensitivity after ceasing oral immunotherapy.
Another effective treatment of oral allergy syndrome could be heat processing. Most proteins in trigger foods are heat liable, meaning they can be broken down by heat. Simply heating or fully cooking trigger foods could remove symptoms.
If you have avoided pollen-related foods because they cause itchiness or swelling in the mouth, you may want to speak with an allergist about other treatment options.