Cap Rast and skin prick


Which is a better indictator of peanut allergy the skin prick or the Cap rast? My son just had his allergy testing - his skin prick wheal was huge like the size of a nickel but his cap rast showed a 1.2 which the allergist said was low but still class 2 which can still be severe. My question is which is right? When she saw the wheal she said that is huge!!! But after the cap rast results she said it was low that he would probably outgrow the allergy. Just confused about this stuff. Can someone shed any light on this?

On Jul 8, 2006

Not to diminish your positive test result... I mean, allergic is still allergic... [img][/img]

A nickel-sized wheal on a skin test isn't "huge." Not in our experience, anyway.

Silver dollar sized is [i]getting there...[/i] Psuedopods? more ominous yet...

SPT for peanut can and do result in systemic rxns in many highly sensitive people (things like a runny nose and lightheadedness).

To answer your question, most FA specialists feel that neither test alone is an indicator of [i]much[/i], including whether or not a child is allergic or not. But the larger the wheal/higher the IgE value, the more likely a true allergy is. In the total absence of a clinical hx, that is.