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About Allergies

Diagnosis

Your Allergist Appointment

Diagnosis

If you think you or your child had an allergic reaction, it is important to see a doctor. Your doctor can refer you to an allergist who can confirm an allergy.  For more information on preparing for your appointment, watch our webinar “Your Allergist Appointment: How to prepare for your visit”.

Here are some of the ways a diagnosis is made:

Patient History

Your doctor or allergist may ask these questions:

  • What happened when the reaction occurred (symptoms)?
  • When did the reaction first start?
  • How long did it last?
  • What treatments were used?
  • Do any other family members have allergies?

Skin Prick Test

This is the most common test used by allergists. Typically, a small drop of the allergen is placed on a person’s arm or back. The skin is then pricked with a special needle so the body can absorb the allergen. After about 15-20 minutes the skin is examined to see if there is any redness or swelling (a wheal). The result will be measured and recorded and then the allergist will determine if it is a positive reaction.

Blood Tests for Allergies

When a person is allergic to something, their immune system reacts by making antibodies called IgE (immunoglobulin E) specific to the allergen (to protect the person against the allergen). A blood sample is taken and then mixed with the allergen. Blood tests measure the level of IgE in the body.

Oral Food Challenge Test

This test should only be done in a medical facility under the supervision of an allergist. If a child seems to have outgrown their allergy, this test may be used. An allergist gives the child increasing amounts of the food in timed intervals. If it is tolerated without any reaction occurring, then the allergist will determine whether the child has outgrown the allergy.

After the Appointment

Once an allergy has been confirmed, it is important to remember to:

  • Avoid your allergen to help prevent future reactions.
  • Carry an epinephrine auto-injector (e.g., EpiPen®) at all times.
  • Wear medical identification such as a MedicAlert® bracelet.
  • Have a written Anaphylaxis Emergency Plan that describes the signs and symptoms of anaphylaxis and instructions on when and how to use the auto-injector. Share the plan with schools, employers, family, and any others who may need to use it.

Treating Reactions

When a person with a food allergy eats their allergen, they will have a reaction. To learn more about anaphylaxis, the most serious form of reaction, please see “What is Anaphylaxis?”. Anaphylaxis is treated using a safe and naturally-occurring substance called epinephrine, which is available in a small device called an auto-injector. If you or your child have been diagnosed with a food allergy, the allergist will prescribe an epinephrine auto-injector. Epinephrine saves lives and you should not hesitate to use it in an emergency.