Peanut allergy scale?


My son had a reaction to peanut butter when he was 1yr. Allergist drew blood and tested which he as at a 9. He is now almost 4 and we just had him retested (blood test) and he is now at 14. We always carry epi pens for him. How severe is a 14? The allergist did not take the time to talk with us. I searched online to try to find a general scale but did not come up with anything. Thanks for any input you share.

By jeremy54235 on Nov 23, 2012

Thank you.

By cathlina on Nov 22, 2012

Here is the scale. I am an almost "3" on the RAST scale and still have had reactions. It sounds like he had a CAP RAST test which is very sensitive allergy test.

Class 0 (<.35) Class I (.35-.7) Class II (.7-3.5) Class III (3.5-17.5) Class IV (17.5-50) Class V (50-100)

By jeremy54235 on Dec 5, 2012

Thanks for sharing all the great information. I was not aware of any of this! My son does also have bad seasonal/environmental allergies as well. His allergist now has us giving him claritin and flonase daily and that seems to really be helping for those allergies. Before he would go through about a half a box of tissues a night. We are supposed to follow up with his allergist in a couple months to see how things are going so i will ask about peanut component panel. We also have a younger daughter and were going to get her tested for the peanut allergy when my son has his follow up appt. Would you recommend get her tested for peanuts because of her brothers allergy to it? Thanks again for all the info.

By DiagnoseTreatPeanut on Dec 5, 2012

The peanut IgE level is concerning at 14 kU/l. Based on selected data from peanut allergy clinics, this has a 95% likelihood of peanut allergy, but the risk of reaction really depends on which specific peanut proteins he is sensitive to. Some proteins such as Ara h 2, are associated with a high risk of reacting to trace peanut, other peanut proteins are as risky as green beans and apples.

Because there are many allergen proteins in peanut you can't really tell from the IgE level alone. As well, children in grade school develop pollen allergies (tree, grass, ragweed) which cross-react with the peanut ImmunoCAP but carry only the risk of a runny nose or itching eyes. You really can't use the peanut IgE level to follow risk after about age 4; kids acquire other cross-reactive sensitivities and often the IgE to peanut increases but the risk of reacting may not. This is a cause of consternation for parents who strictly avoid any exposure to peanut but see the IgE levels increase.

If you would like to know the actual risk of reaction you could ask your doctor to order a peanut component panel so that you and your doctor have a much clearer idea of risk and progress. Be cautious if there is IgE to Ara h 2, anything over 0.35 kU/l; this would make a peanut challenge unnecessary.

I hope this helps. Keep in mind the history of reacting or not reacting to peanut trumps the lab value no matter how high or low.

By DiagnoseTreatPeanut on Dec 5, 2012

Most parents feel better knowing if a sibling is also peanut allergic. You could start with a the ImmunoCAP to peanut alone, and if this is more than about 1 kU/l order the peanut panel.

You might consider having the labs drawn ahead of time so that you and your doctor will be able to discuss the results and come up with a treatment plan during the visit.

By eastcoastmom on Mar 12, 2014

I just got our peanut component test back. It said my dc has a 1.2 to the ara2. I am confused. The doctor said he would still want to do a office challenge to this. He added that component testing is more helpful at this point in bringing in a child who had a rast over say a 15 which would not be a number to challenge but if their component was all to ara8 it would be worth it. Wondering why another doc wouldn't challenge at all if there was ara2 that had any IGE. Also wondering if anyone has known children who have outgrown even with serious allergy. My son started at a 2 and is now a 1.2 so I am hoping to hear someone with a positive story:)