Skin Prick test today

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Hi Can anyone tell me if the size of the skin prick wheel has anything to do with the severity of the peanut allergy? My son's wheel for peanut was huge about the size of a nickel and the dr said he is majorly allergic to peanut so she ordered a cap rast test. I am just confused!!!! I had a sad hope that maybe he would have outgrown it! So sad! At least he tested negative for everything else, but a small positive to egg white. I don't know why I feel so sad!

On Jun 23, 2006

I have the exact same question. My DS's wheal for PN was about the size of a nickel as well The allergist did NOT do any sort of RAST b/c he said he believed that size is enough for the allergy to be ON. He said when we go back in a year (when DS is 3) and if the wheal is smaller, he'll do a RAST. I'm assuming this means the size of wheal is associated with the severity of the PA, but I know you can have a severe reaction just "out of the blue" even if you have a small RAST (right?). I thought my DS's wheal was small b/c my DH had a skin prick allergy test for ragweed about a year ago and his entire forearm (I'm talking a spread of about 10-12 INCHES!) blew up in a reaction...and stayed that way for DAYS! So, I thought a nickel-size wheal was SMALL! Now I'm reading more that this isn't so small. Thoughts out there??? A million thanks! Jen

On Jun 23, 2006

This is interesting. My RAST from last year was about .52, a low class 1. But my wheal was huge.

What I'm really wondering is this: my peanut wheal, although huge, went away within the hour. My pollen, ragweed, dust, dog, etc. wheals didn't go away for THREE DAYS. Is this because the other things are in the air so I was still being exposed to them after the test?

On Jun 23, 2006

Don't know... but FWIW, DD's skin tests have always resulted in wheals which were in many case far larger than a nickel... AND were recurrent (popped for days afterwards). Not the environmentals... but pistachio, almond and egg. Of course, allergist doesn't ever want to skin test again for pistachio... he didn't think she could have been sensitized. We only thought it was [i]theoretically possible[/i]... she had a welt the size of a silver dollar and it had pseudopods. That came back for about a week anytime her arm warmed up or Benadryl wore off.

So to make a long story short, I don't think that size matters. Much. There's negative, there's positive, and there's ooooo... we shouldn't do that [i]ever[/i]again.

(We've never skin tested for pn... too dangerous in our case.)

On Jun 23, 2006

The peanut wheal went away within the hour, but it was a little red there tonight. No hive just red. The egg white wheal was 3mm and it went away immediately. I was very happy that he did not develop new allergies. I am scared to see the cap rast scores. I just hate this allergy!!!!!!!!!

On Jun 23, 2006

I don't know if the size of the wheal matters. When my dd first had a spt, she had a wheal for egg that was a little larger than her peanut wheal. She had a reaction to egg at 9 months (gave it to her upon ped. advice) but I didn't realize that's what was going on. Instinctively I withheld eggs for about 9 months and she had been eating them for about 6 months when this test was done.

Anyway, the allergist decided to do a CAP RAST for the egg only, since we'd be avoiding peanut for a couple of years regardless of any blood test results. It was 1.61 and we did a challenge, which she passed and has eaten eggs ever since with no problem.

Having said all that, she apparently had already outgrown the egg allergy at the time of the spt but still developed a wheal. Since that can happen, I'm not sure the size of the wheal can mean a lot. If you can still develop a wheal when you're no longer allergic, it doesn't make sense that it would be a good indicator of potential reaction. I hope all of that made sense [img][/img]