Allergy skin tests are a safe, fast, painless, accurate and relatively inexpensive method to identify the allergens that trigger a patient’s allergy symptoms. Identifying the specific allergens behind a person's symptoms is important because it helps physicians create a treatment plan aimed at managing or eliminating allergy symptoms.

A patient can be tested for up to 30 allergies at the same time. However, a physician usually will test only the suspected symptom triggers. Typically, allergy skin tests are used to uncover reactions to the following potential allergens:

• Tree, shrub, weed and grass pollens
• Molds
• Household dust and dust mites
• Animal dander and feathers
• Foods (skin testing for food allergies is not always as accurate and some foods may respond better to skin testing than others)
• Medications
• Insect venom

Allergy skin tests can be safely performed at any age. However, they may not be as sensitive in children under the age of 3 and adults over the age of 60. In addition, people with the following health conditions may yield less accurate results:

• Severe eczema
• Psoriasis
• Chronic renal (kidney) failure
• Cancer
• Spinal cord injuries
• Peripheral neuropathy (failure of the nerves that carry information to and from the brain and spinal cord)

In addition, patients on some types of medication (especially antihistamines) may also yield less accurate results.

For these individuals, a blood allergy test known as a radioallergosorbent test (RAST) may provide a better alternative for diagnosing allergies. During an allergic reaction, the body produces immunoglobulin E (IgE) antibodies to protect against what it mistakenly perceives to be a dangerous substance. The RAST test measures the amount of specific IgE produced to an individual allergen in a sample of blood.