Why did I test positive for IgE RAST?

Question

Hello doctor,

My test report was negative in the IgE test a year ago. Now I got a positive IgE RAST for gluten, eggs, peanut butter, and milk.

What might be the cause?

I have struggled with sinus issues all my life, and currently, I am taking Singular when needed and Benadryl. I was referred to an ENT specialist or allergist because of recurring sinus infections.

Kindly help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

Specific immunoglobulin E (IgE) testing for allergens is not as accurate as skin prick allergy testing. It is possible to have a negative result in one and a positive in another. The factors affecting the result could be the test itself or the reagents and the lab.

I suggest skin prick allergy testing. This is the gold standard for allergy diagnosis. The allergens you have tested positive for are all foods that are slightly less important in your condition as they are more likely to be caused by inhalant aeroallergens.

Have you checked sensitivities for aeroallergens for your allergy or sinus symptoms?
Did they check sensitivities to dust mites, cockroaches, insects, funguses, pollens, and animal dander?

Please reply for further management.

Thank you.

Answer 2

Hello,

Welcome back to icliniq.com.

Although you had all these foods till now and they did not cause any harm, it is not very sound that suddenly you turned allergic to these, and consuming them now would result in life-threatening anaphylaxis.

Till we get a final diagnosis, avoid consuming these. Get tested for these substances again using the skin prick method and not via specific IgE. I suggest a skin prick allergy test for these food allergens as well as the aeroallergens.

I hope this helps.

Thank you.