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Food allergy

A food allergy is an immune response. It is mostly triggered by milk, wheat, eggs, soy, nuts, seafood, but other foods can be allergens also. Your immune response overreacts when you have a food allergy. Your immune system launches a response when it recognizes a food allergen. Chemicals such as histamines are released. These chemicals can lead to allergy symptoms.

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Causes

The most common food allergies are:

  • Milk
  • Wheat
  • Eggs
  • Soy
  • Nuts
  • Seafood

Oral allergy syndrome (OAS)

This is an allergy type syndrome that affects the mouth and tongue after patients eat certain fresh fruits and vegetables, spices, and nuts.

  • These foods have substances that are like some pollens. It is thought to be a cross-reaction.
  • The reaction usually happens when you eat the raw form of the foods.
  • This is a mild reaction that needs an epipen prescription.

Pollen food allergy syndrome (PFAS)

This is a more severe form. It can cause whole-body reactions to these foods.

Symptoms can be:

  • Hives
  • Itching
  • Swelling especially of the eyes, face, lips, and tongue
  • Wheezing
  • Lightheadedness or fainting
  • Nasal congestion, runny nose
  • Stomach cramps, diarrhea, nausea, or vomiting
  • They start within minutes up to 2 hours after eating.

OAS symptoms are:

  • Itchy lips, tongue, and throat
  • Swollen lips (sometimes)

Exams and tests

  • Blood or skin tests can be used to confirm that you have an allergy.
  • A food challenge is the best way to diagnose food allergies. Challenge testing should only be done with your health care team.

Treatment

  • Do not have the food. This is the most effective treatment.
  • Desensitization. You will eat a small amount of the food each day.
    • This must be done with an allergist.
  • Antihistamines can be used to treat minor symptoms.
  • You should be prescribed injectable epinephrine if you have been diagnosed with a food allergy.
    • You should be taught how to use it.
    • Always keep it with you.

If you get any type of serious or whole-body reaction after eating the food:

  • Inject the epinephrine.
  • Call 911.
  • or
  • Go to the nearest hospital or emergency facility right away.

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