During allergy skin tests, your skin is exposed to suspected allergy-causing substances (allergens) and is then observed for signs of an allergic reaction.
Along with your medical history, allergy tests may be able to confirm whether or not a particular substance you touch, breathe or eat is causing symptoms.
Allergies occur when your immune system, which isyour body’s natural defense, overreacts to something in your environment. For example, pollen, which is normally harmless, can cause your body to overreact. This overreaction can lead to:
- a runny nose
- blocked sinuses
- itchy, watery eyes
Information from allergy tests may help your doctor develop an allergy treatment plan that includes allergen avoidance, medications or allergy shots (immunotherapy).
Allergy skin tests are widely used to help diagnose allergic conditions, including:
- Hay fever (allergic rhinitis)
- Allergic asthma
- Dermatitis (eczema)
- Food allergies
- Penicillin allergy
- Bee venom allergy
- Latex allergy
Allergens are substances that can cause an allergic reaction. There are three primary types of allergens:
- Inhaled allergens affect the body when they come in contact with the lungs or membranes of the nostrils or throat. Pollen is the most common inhaled allergen.
- Ingested allergens are present in certain foods, such as peanuts, soy, and seafood.
- Contact allergens must come in contact with your skin to produce a reaction. An example of a reaction from a contact allergen is the rash and itching caused by poison ivy.
How to Identify?
Before your allergy test, your doctor will ask you about your lifestyle, family history, and more.
They’ll most likely tell you to stop taking the following medications before your allergy test because they can affect the test results:
- prescription and over-the-counter antihistamines
- certain heartburn treatment medications, such as famotidine (Pepcid)
- anti-IgE monoclonal antibody asthma treatment, omalizumab (Xolair)
- benzodiazepines, such as diazepam (Valium) or lorazepam (Ativan)
- tricyclic antidepressants, such as amitriptyline (Elavil)
Allergy tests may result in mild itching, redness, and swelling of the skin. Sometimes, small bumps called wheals appear on the skin. These symptoms often clear up within hours but may last for a few days. Mild topical steroid creams can alleviate these symptoms.
What to Do?
An allergy test may involve either a skin test or a blood test. You may have to go on an elimination diet if your doctor thinks you might have a food allergy.