"allergic" reaction but negative allergy tests?

[bectoria]

My dd is 18 months old and has had issues with several different foods. Bananas caused a classic bullseye rash on her bum, as did avocado, kiwi, and mango (all in the latex family). Milk caused runny poo and eczema - cutting dairy out of her diet cleared the eczemea within days. She gets itchy mouth and lime green foamy poo after eating potatoes and chicken nuggets . We had her tested for all of these food allergies via scratch test and RAST - she was negative to EVERYTHING. Here's the thing that really confuses me - the allergist gave us some Zyrtec to use if dd had a reaction and it cleared the reactions up within a half hour each time.

So what could it be if it's not an allergy? THe allergist mentioned something about it possibly being an IGG instead of an IGE reaction...I can find almost NOTHING on IGG reactions, though. Obviously, we'll avoid the foods that cause her problems, but I'm more confused than I was before the testing, honestly.

Becky

[dakotamidnight]

i'm interested in this as well - I am allergic to peach fuzz and peanuts, but never react with a skin test.

My Dr said it was fairly common, but didn't explain it - just gave meds.

[JenniferKSwan]

I have been told and read that the only way to truly know if you are allergic to an item is exposure. Frustrating, I know!

[daniusa]

false negatives

Someone told me recently that allergy test often bring up false negatives (but never false positives).

[daniusa]

false negatives

Someone told me recently that allergy test often bring up false negatives (but never false positives).

[sweetangelbrynlie]

She could still be allergic to the foods. Before the age of 3 my daughter never tested allergic to peanuts, but still broke out into hives, swollen lips, ect from them. The test kept saying there was no peanut allergy. The she had another test at around 5 years old which showed her allergic to peanuts at a level 5 I think?

[wendy1221]

Reaction ALWAYS trumps test.

[mtm]

food intolerance instead of actual allergy maybe? My ds was diagnosed with an allergy when he had eye swelling after dairy. Six months later he tested negative on the scratch test although I know its still an intolerance (gastro issues when I screw up and eat something with hidden dairy).

[talia rose]

Yes, an intolerance is different than an allergy. as a child i had multiple allergies that came up on that test but they never got to my real problem which was gluten intolerance. any chance you can find a kinisiologist (muscle testing) that tests for food intolerances?

[Cate]

My son has a lot of food allergies, and my doctor told us that there's no point in even bothering with testing until he's at least 2, before that false negatives are very common, so we wouldn't really learn anything from it.