U.S. doctors online nowAsk doctors free
A 36-year-old member asked:

What is a class 3 allergy?

3 doctor answers3 doctors weighed in
Dr. Stevan Cordas
Internal Medicine 58 years experience
Class 3 allergy: This is confusing. First, in doing prick tests for allergies on the skin we grade it from one to four. Secondly some use such a term for anaphylaxis wich is not neccessarily ige mediated http://www.Ajronline.Org/content/190/3/666.Full then there are gell-combs reactions which are type i to iv is that what you mean?
Created for people with ongoing healthcare needs but benefits everyone.
Dr. David Shulan
Allergy and Immunology 42 years experience
Type 3: I assume you mean a type 3 immune reaction which is caused by immunoglobulins (antibodies) binding specific materials (antigens) forming a complex that can activate materials in the blood to cause inflammation. This can occur in serum sickness, lupus, hepatitis and many other conditions.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Steven Machtinger
Allergy and Immunology 45 years experience
Moderate RAST result: Dr. Shulan is correct: type 3 immune reactions involve igg & antigen. "class 3 allergy" may also refer to rast, a blood test for detecting ige against antigen. For convenience labs define from 5 to 7 levels. Class 2 is often borderline & class 3 low positive. But positive is positive. There is little significant difference between class 3 & class 6. Photo: dr & dr ishizaka, discoverers of ige.
Created for people with ongoing healthcare needs but benefits everyone.

Related questions

A 18-year-old female asked:
I want to know three causes of food allergies?
2 doctor answers2 doctors weighed in
A 25-year-old member asked:
What does a class 3 allergy to eggs mean?
2 doctor answers5 doctors weighed in
A 34-year-old member asked:
Will my three year old grow out of his food allergies?
4 doctor answers7 doctors weighed in
A 47-year-old member asked:
Anaphylaxis, allergy and hypersensitivity, what's the difference between these three?
1 doctor answer10 doctors weighed in
Last updated Oct 18, 2016
Connect with a U.S. board-certified doctor by text or video anytime, anywhere.
24/7 visits - just $39!
50% off with $15/month membership


Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.