Patient Information of Allergies
Are Allergies Rare?
No. Approximately 20% of the U.S. population has one or more types of allergy. Allergy symptoms account for more visits to the doctor’s office than any other single disease and are a leading cause of school absenteeism in this county.
What Are Allergies?
Allergies are abnormal physical reactions you experience when you are exposed to substances (allergens) to which you have developed an allergy. These substances are usually harmless and do not produce symptoms in normal, non-allergic people.
How You Become Allergic
Your body produces antibodies to ward off infection and other diseases. When your immune system misidentifies a normally harmless substance, it begins building antibodies toward that specific substance. These antibodies in your blood trigger allergic symptoms when you are re-exposed to that substance. Measurement of these antibodies is the key to effective allergy diagnosis and treatment.
How You Get Exposed to Allergy Producing Substances
The air you breathe contains minute particles. The type of particles in the air will vary according to your location, the time of year, and moisture in your environment. Common causes of inhalant allergies are:
- Plant Pollens-Trees, Weeds, and Grasses
- House Dust Particles
- Mold Spores
- Animal Hair and Danders
- Insect Particles
Foods you eat can also cause allergic reactions but usually produce different symptoms. Substances you touch can cause allergic reactions and are usually evident in the form of a rash on parts of your body.
Are Allergies Inherited?
No. But the tendency to become allergic can be inherited. Studies show if one of your parents had allergies, you have a 50% chance of becoming allergic. If both of your parents were allergic, your chances of developing allergies are as high as 80%.
How to Find Out If You Have Allergies?
Allergies can be complex and sometimes very difficult to diagnose since the same symptoms produced by allergies can also be caused by non-allergic conditions. Your doctor will evaluate your history and physical examinations when he is considering allergy testing. If the cause of your symptoms can not be determined through information from your history and physical, more extensive investigation will be necessary.
Allergy tests can be performed by skin testing or by a sophisticated blood test called RAST (Radio-allergosorbent Test). RAST testing offers many advantages:
A single blood sample taken from your arm will be sufficient for performing all the needed tests.
Excess blood is stored for additional tests in the future (if needed). Medications you may be taking will not affect the RAST test thus need not be discontinued for allergy testing.
RAST requires only one puncture to obtain a blood sample. Skin tests require a puncture for each test performed.
RAST testing provides specific information regarding the level of allergy antibodies in your blood. Skin conditions which might make skin testing difficult do not affect the outcome of the RAST test.
Skin testing can sometimes provoke an allergic reaction, while RAST testing is performed in the laboratory and does not present this hazard.
Because of the accuracy, safety, and convenience of RAST testing, it has become an economical way to diagnose allergies.
RAST testing may even be performed to “rule out” allergies so your doctor knows to further investigate other causes of your symptoms.