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Diagnostic Tests for Allergies

Diagnostic tests for Allergies:

Respiratory allergies can be difficult to diagnose and thus may be both over-diagnosed and under-diagnosed at different times. A full evaluation by a medical professional, primary care physician or nurse practitioner, pediatrician, in conjunction with an allergist and asthma specialist, as indicated, is necessary to properly diagnose respiratory allergies and the allergens that cause them.

The most common form of testing for respiratory allergies is skin testing, most often the "scratch test". This test includes putting a small amount of a possible allergen on the skin of the arm or back, then scratching or pricking the skin so the substance inters the body. The patient is then observed for a reaction to that substance, such as redness or swelling. Multiple possible allergens can be tested at one time.

Home Diagnostic Testing

These home medical tests may be relevant to Allergies:

Tests and diagnosis discussion for Allergies:

Something in the Air Airborne Allergens: NIAID (Excerpt)

If the patient's medical history indicates that the symptoms recur at the same time each year, the physician will work under the theory that a seasonal allergen (like pollen) is involved. Properly trained specialists recognize the patterns of potential allergens common during local seasons and the association between these patterns and symptoms. The medical history suggests which allergens are the likely culprits. The doctor also will examine the mucous membranes, which often appear swollen and pale or bluish in persons with allergic conditions.

Skin Tests

Doctors use skin tests to determine whether a patient has IgE antibodies in the skin that react to a specific allergen. The doctor will use diluted extracts from allergens such as dust mites, pollens, or molds commonly found in the local area. The extract of each kind of allergen is injected under the patient's skin or is applied to a tiny scratch or puncture made on the patient's arm or back.

Skin tests are one way of measuring the level of IgE antibody in a patient. With a positive reaction, a small, raised, reddened area (called a wheal) with a surrounding flush (called a flare) will appear at the test site. The size of the wheal can give the physician an important diagnostic clue, but a positive reaction does not prove that a particular pollen is the cause of a patient's symptoms. Although such a reaction indicates that IgE antibody to a specific allergen is present in the skin, respiratory symptoms do not necessarily result.

Blood Tests

Although skin testing is the most sensitive and least costly way to identify allergies in patients, some patients such as those with widespread skin conditions like eczema should not be tested using that method. There are other diagnostic tests that use a blood sample from the patient to detect levels of IgE antibody to a particular allergen. One such blood test is called the RAST (radioallergosorbent test), which can be performed when eczema is present or if a patient has taken medications that interfere with skin testing. (Source: excerpt from Something in the Air Airborne Allergens: NIAID)

Allergies: NWHIC (Excerpt)

Often skin tests or blood tests are used to determine specific antibody levels reacting to a certain allergen. If there are unusually high levels of an antibody known as IgE, it is a good indication of an allergic reaction. (Source: excerpt from Allergies: NWHIC)

Diagnosis of Allergies: medical news summaries:

The following medical news items are relevant to diagnosis of Allergies:


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