Diagnostic Tests

Skin tests for allergic disorders have been used successfully for more than 100 years. Today, prick or scratch tests are commonly used by allergists as diagnostic aids. The skin prick test involves pricking the skin on the back or the forearm with a small amount of a diluted allergen (substance that may be causing your symptoms). The health care provider closely watches the skin for swelling and redness or other signs of a reaction. Results are usually seen within 15-20 minutes. If the results of the prick or scratch tests are negative, they may be followed by intradermal tests, which give allergists more details about what is causing the underlying symptoms.

Patch testing checks for chemicals that cause a delayed allergic reaction, such as contact dermatitis. This test is performed by placing a safe, chemical patch on the person’s back. This patch stays on the skin for two days before being removed to be examined. It is again examined three to four days later to make sure nothing new has developed. The test is considered positive if vesicles, bumps or swelling develop.

This test is typically administered for those who are unable to undergo a skin test due to antihistamine use, skin disease, chronic hives or an immune system disorder. By taking a sample of blood, this test can determine environmental allergies or food allergies, as well as immune system deficiencies.

Pulmonary function tests (PFTs) are noninvasive tests that show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This information can help us diagnose and decide the treatment of certain lung disorders. PFTs may be used to check lung function before surgery or other procedures in patients who have lung or heart problems, who are smokers, or who have other health conditions. Another use of PFTs is to assess treatment for asthma, emphysema, and other chronic lung problems.