With allergy testing, it is important to look at symptoms as well as the class of allergy.  Our office does not do skin prick testing, but can order blood tests to test against many food and environmental allergens.

How can I tell how severe an allergy is from the test?

Blood tests are graded by Class.  Class 0 is no allergy, Class 6 is severe, classes in between are in between.  Within each class we can look at more specific values to track sensitivities to known allergies, but for simplicity, parents can follow classes. 

Symptoms do not always correlate with class.  We use a combination of symptoms from exposures and the results of the test to determine what a person is allergic to.  We usually don’t count Class 1 as a probable allergy unless symptoms occur with that allergen.  Usually higher level classes show some symptoms in a person.  Sometimes people test positive on the blood test, but do not have any symptoms when exposed.  It is okay to continue exposures unless symptoms are noticed.  Other people have symptoms when testing is negative (ie no allergy).  If symptoms are present, it is best to avoid whatever causes the symptom, regardless of the test results.

How do I use these results?

We use allergy test results to avoid the things we are allergic to if possible (such as certain foods or animals).  If we cannot avoid altogether, we can use seasons to guide when to treat with medication, such as adding the medicine during ragweed season then stopping it if that is the only thing we are allergic to.  See below for "Food" or "Environmental" allergy specific information.

Food allergies:  Food allergies are treated by avoidance primarily, so it is important to document a true allergy, not just a positive blood test.  Most kids don’t have symptoms with Class 1 allergens, so if you don’t notice problems with that food, you can still feed that.  Some kids seem to have obvious reactions on several occasions to a food that shows no allergy on testing.  We recommend avoiding that food since the symptoms show allergy.

With all positive food allergy testing (except nuts - see below) we suggest an avoidance diet followed by trial of the food to see if the testing matches the symptoms.  Sometimes the tests show a reaction, but the child does not show a reaction.  Those foods are ok to feed.  Sometimes after a trial off the food that has shown a reaction on testing, a person has a noticeable reaction, even though a correlation was not seen in the past.  Continue to avoid this food for at least 6 months.

• Start with a 2 week period of none of the foods that show an allergy.
• Add one thing at a time each week to watch for symptoms.  Symptoms might be vomiting, diarrhea, congestion, cough, blood in stool, rashes, or irritability.
• If the symptom is mild, you can stop that food again and re-try in a couple months.  The reason for that is it is possible to be reacting to something else, and you want to be sure it is a true allergic reaction.  Also, with most foods, kids lose the allergy after avoidance of 6 months.
• If it is a noticible reaction with introducing a food, this indicates a true allergy: keep off that food entirely for 6 months.  Read package labels for hidden foods.  We usually suggest every 6 months trying the food again starting with small quantities and gradually increasing as long as there are no symptoms.  For instance, an infant with milk allergy can be on soy formula until the 1st birthday, then try milk products at 1 year.  If symptoms return, return to soy formula (not skim milk at this age!) until 18 months, then try again, etc.
• With multiple food allergies, resume only one food at a time.

With nut allergies the story changes.  Nut allergies tend to get worse with time, not better.  With those, we tell parents to avoid nuts.  After a year we can re-test to see if the nut reaction is still there (sometimes the tests over read).  If it is still there, avoid all nuts.  If it is not there, we will discuss whether or not to do a trial.

It is very important to read food labels and learn the different ways that a food might be listed.  There are wonderful websites listed below that you can learn more about food allergies.

For more information on food allergies, please visit the American Academy of Allergy and Immunology and The Food Allergy and Anaphylaxis Network.

Environmental allergies:  Some people can avoid cats, dogs, or other environmental allergens.  Some allergens, such as molds and pollens can never be entirely eliminated.

• Monitoring symptoms and using resources, such as the internet, to guide when to begin medications is a good strategy.  One site to monitor allergens:  Pollen
• Use symptoms and allergy levels to stop medication when a season is over.
• Some allergens are year round, and it is safe to continue medications year round.  Some people require a baseline medicine year round, and add a second medicine during peak seasons.  This also is okay.  Check with your doctor to see what is right for your symptoms.
• Other strategies for helping allergies:
• Shower before bed.  Sleeping with pollen or other allergens (and irritants such as cigarrette smoke) can increase symptoms because you roll around on the pillow, re-breathing all the particles.
• Nasal rinses with saline.  Flushing all the pollen and irritants out of the nasal passageways with saline, available at pharmacies, is a safe and effective way to control symptoms.  Saline is now available with xylitol, which may prevent ear and sinus infections (both are complications of chronic congestion from allergies).
• Wash sheets weekly.
• Wash eyelids.  If eye symptoms are present, washing the eyelashes after being outdoors can remove pollen.  Use a tear-free shampoo to avoid burning in the eyes!