Please help understand RAST Class designation

I dont focus on the testing place.

I focus on the scores, right or wrong.

For us, the numbers all just numbers... If there was a negative in the testing, that'd be one thing...

3 yrs of testing (at LEAST) and no negatives... Im growing impatient. [img]http://uumor.pair.com/nutalle2/peanutallergy/smile.gif[/img]

Jason

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[b]* Obsessed * [/b]

I know Jason...really I do. But I guess everyone has to have a little bit of positive to hang onto? My last allergist told us to expect the numbers to go up until he hit 12-14 yrs old, regardless of complete avoidance, so when the numbers went down she said we should be 'happy'. Our new allergist feels the same.

Well...I'm just hoping the numbers are still trending down because at least I feel like I must be doing my job...avoidance. But what's the point if I can't even compare the numbers? What do they even mean if the class designations vary by lab?

Luvmyboys

My allergist says to forget the numbers....DS is allergic and the numbers don't necessarily mean severity.
We had one ANA reaction when DS was 4. We re tested when he was 6 with RAST. The rast was zero for egg whites, and two types of shellfish, it was very low for peanuts.
At this point, doctor said, okay we have some good negative tests and a very low peanut result. We did SPT to confirm tests. The tests all came out negative except the peanut which had a 16mm wheal and he was extremely itchy.
So, based on the two tests, we have to continue treating DS as if he is highly allergic.
Quite honestly, I would concern myself more with avoiding ana reactions and exposures, continuing to educate your child and others to deal with the allergies instead of trying to predict whether your child will outgrow the allergy. I don't think the test numbers can predict this.
Good luck

Never mind the future (THAT FAR).

Weekend is coming soon!! [img]http://uumor.pair.com/nutalle2/peanutallergy/smile.gif[/img]

Hugs!

Jason

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[b]* Obsessed * [/b]

i'm not sure about comparing year to year rast numbers (because we have only had one rast done and it was done last month). all other testing ever done has been spt.

i just got the report in the mail today for both girls.

chase, age 7, is class 3 and 15.10 (?)

bryce, age 10, is class 5 and 70.30 (?)

interestingly, (or maybe not, because i have no idea what any of this means), even though their numbers seem quite different to me the allergist enclosed a letter saying:

"enclosed are the copies of the RAST results obtained on bryce and chase for peanut. they were both significantly reactive to the penaut protein and should continue avoidance of all peanut products indefinitely. an epipen and benadryl should always be available."

so...i guess the lower number is considered as "significant" as the higher number. ????

As our allergist explained it, (and I verified this by researching myself), with most other foods/allergens except for peanuts, the magnitude of the RAST result roughly correlates with the severity of the reaction you might expect if exposed to that allergen.

With peanuts though, all they can say for sure is that with an IgE above 15, you are 95% likely to have some kind of reaction if exposed to peanuts. The severity does not correlate to the IgE, and it is possible that the severity of subsequent exposures would vary in the same patient.

Basically, that the PA is much more unpredictable than other allergies.

Hope this helps.