There are many factors involved in an accurate diagnosis and an effective treatment plan.
Anywhere from 40 million to 50 million Americans have allergies or asthma. These diseases are so common that it might seem like the diagnosis and treatment are straightforward and that any doctor should be able to administer the most effective therapies.
This specialized training allows allergists to expertly:
- Perform allergy testing
- Identify the source of your suffering
- Accurately diagnose your condition
- Treat more than just your symptoms
- Develop a personalized plan that eliminates your symptoms
- Provide you with the most cost-effective care that produces the best results
Two key steps in the process of allergy diagnosis are the medical history and allergy test selection. Allergists use their skills in these areas to help more patients feel well, stay active during the day, and rest at night. And that’s nothing to sneeze at.
Why Take a Medical History?
When it comes to human allergic disease, an individual’s medical history is as important as the results of an allergy test. Medical history is the critical link between allergy test results and allergic disease itself.
Allergy skin testing is the gold standard and is used along with the medical history to establish a diagnosis. Both blood and skin allergy tests can detect a patient’s sensitivity to common inhalants like pollen and dust mites or to medicines, certain foods, latex, venom, or other substances. Generally skin testing is the most accurate and preferred method used by trained allergists. Allergy blood tests may be ordered in certain specific situations, such as severe skin rashes, or if it is impossible to stop a medication that interferes with the interpretation of the skin test.
If the results of skin and blood allergy tests are not clear or are inconsistent with the patient’s medical history, allergists rely on their training and experience along with a patient’s medical history and a physical examination—not test results—to make the final diagnosis.
Research confirms what allergists already know: Allergy tests are valuable for their ability to give accurate and reliable results that confirm information gathered in the medical history.
Why Is Allergy Test Choice Important?
An important related consideration is for health practitioners to choose the right test, the one best able to aid the diagnostic process. For many reasons, that’s not an easy job. Allergy patients are often sensitized to many allergens, but are only clinically allergic to one or more specific substances. Allergists are trained to select tests that pinpoint the relevant allergen, which enables them to develop optimal therapies for each patient.
Board-certified allergists recognize that not all allergy tests are alike. They regularly review the scientific literature to learn which testing systems work better than others and the laboratory practices that may affect test results.
Allergy tests should not be ordered randomly, either. They are chosen based on symptoms, environmental and occupational exposures, age, and even hobbies. All results are then interpreted in the context of the patient’s medical history.
Get the facts: Make an appointment with a board-certified allergist in your area.
How An Allergist Diagnoses Allergies
If you have never been diagnosed with allergies but think you might have them or aren't sure what causes your allergy symptoms, see an allergist.
When you visit an allergist, the doctor will:
- Take a medical history. You will be asked about your health, your symptoms and whether members of your family have asthma or allergies such as hay fever, hives or skin rashes like eczema.
- Ask you about your symptoms. The doctor will want to know when symptoms occur, how often they happen and what seems to bring them on. The allergist will also ask about your work, home and eating habits to see if these can provide clues to help pinpoint your allergy.
- Do a physical exam.
- Conduct allergy tests.
Tests can be done for common allergens such as plant pollens, molds, dust mites, animal dander, insect stings and various foods such as peanuts, eggs, wheat, shellfish and milk. Testing also is available for some medicines, such as penicillin. There are two types of skin tests:
- The prick test pricks the surface of the skin with a tiny amount of the allergen. The test is done on your back or the inside of your arms with several allergens tested at once. If you're allergic, redness and swelling appear at the site of the prick.
- The intradermal test injects the allergen with a very fine needle under the first few layers of the skin. This type of skin test may be used when the result of a prick test is not clear.
Allergy Blood Tests
Skin tests are more sensitive than blood tests, but an allergist might use a blood test to diagnose allergies if:
- You're taking a medicine that could interfere with allergy test results.
- You have very sensitive skin or a serious skin condition.
- You had a previous reaction to an allergen that suggested you were very sensitive and should avoid more exposure.
After drawing blood, the sample is sent to a lab to look for the antibodies of specific allergens that show if you have allergies. It takes a few days to receive blood test results.
No matter what type of allergy test is given, allergists are experts at selecting which allergens should be tested, reviewing the results, and helping you find the right treatment for relief.