negative blood test questions

[ashleyhaugh]

ds reacts to all dairy products, we noticed it at about 3-4 months old. gastric issues if its just a little (like too much soy cheese, he started to be able to handle a little bit of it 6 months or so ago, he just turned 2) that plus rashes if its more (a friend shared her cheese with him and his entire chest and belly broke out while he was still chewing).he also gets a runny nose and eyes. i have to read the labels on everything.

we were told they wouldnt test til he was 2, so when he turned 2, i got the consult put in, lol.

we didnt do the skin prick test because it required him to be off his zyrtec (for seasonal allergies) for 4 days, and i had just started a new job and didnt want to have to request more time off (i honestly wasnt expecting to have the test done that same day).

anyway, blood test it was. they tested for milk and casein. i got a call back from the doc the other day saying both came back negative.

im not sure what to think. i was positive it was an allergy, but now im not so sure. i know its not lactose intolerance, because he reacts to lactose free things, like the soy cheese.

what do i do next? i need to call the doc and set up a skin test i think. he called while i was at work, so i just got a voice mail. is there anything else that should be tested for besides milk and casein?

whats the likely hood of having a false negative blood test?

[changingseasons]

NO allergy test is 100% reliable. That said, dairy intolerance (which is completely different than lactose intolerance, btw) is more common. You can get an ELISA or ALCAT test for IgG allergies/intolerances, but most allergists don't believe in them. Your ped might be able to order it. Although with that fast of a reaction, a true IgE allergy seems possible. I would try for the skin prick test if possible. Sometimes you can get completely different results on the SPT and RAST. (DD was negative on the RAST, but had a HUGE reaction on the skin test for dairy. Opposite for peanuts- bigger positive on the RAST than the skin test.)

But I'm confused about something- they wouldn't test him for allergies, yet are MEDICATING him for allergies?

[ashleyhaugh]

i know right? hx is in the military, so we have exactly been consistant with doctors. moved when he was 9 months, and again just before he turned 2, and didnt do much beyon well baby visits.

his first ped gave us zyrtec when he was about 3 months old- before we figured out the dairy allergy. he wasnt tested, but it helped. he used it in georgia, didnt need it the year we were in louisiana, but needed it again almost as soon as we got to san antonio (mine are awful too since we've been here)

allergy back story- he had runny nose and eyes, which we thought was seasonal allergies, it was georgia after all, and eczema, which we didnt think much about. then he got what i (and the doc we say for the script) was a yeast rash, but the 2 weeks on the cream did nothing for it i started researching allergies. when i cut dairy out, the eczema cleared immediatly, the other stuff followed. the eczema would always get bright red (it was only one area on his back that had it) almost immediatly when i accidently had something with dairy in it.

since we cut out the dairy, we rarely see a rash reaction, i guess since when he does have something, its usually a tiny amount thats in something. we usually get the gastric issues instead- painful gas that keeps him up screaming at night, constipation, diareah, poop that smells like something died. the rash we got with cheese was a couple of montha ago, and before that we hadnt seen a skin reaction in probably close to a year.

any way, when we got to louisiana, we had to get a referral to a burn center (his foot was burned when he was about 4 months old by a clumsy waitress) for a final follow up, and asked about allergy testing too. we were told they dont test before age two. i mean im sure they'll test for something potentially life threatening, but we had it under control more or less, so they said to just keep eliminating it like we were doing (pretty much the same thing his first ped said too)

i had every intention of having all my research about the tests and stuff done and ready when it came time for the consult, but then life happened. xh sprung a divorce on me, and my focus has been other places, iykwim, and before i knew it my baby turned 2 (

[luminesce]

The blood test only looks for IgE allergies. It is rare to get a false positive and more likely that you get a false negative. I do not know the likelihood of a false negative happening, however. I don't think it is extraordinarily common.

It could be an intolerance, not an allergy. If it were me, I'd stay clear of the food as long as it is causing a reaction. Doctors/allergists sometimes can't see the forest for the trees when it comes to food intolerance. The idea of "If it isn't an allergy, he can have it" just doesn't pan out in reality. Our DS has horrible diaper rashes as reactions to several foods but no allergy to any of them.

He may grow out of it so you could trial it every six months or so. I'd also do a blood retest at some point (maybe 1 year?) just to be *sure*. The instantaneous reactions make me think it could be a missed IgE allergy so I'd still be very careful - the blood tests aren't 100% reliable.

[lil_miss_understood]

Originally Posted by serenitii

The blood test only looks for IgE allergies. It is rare to get a false positive and more likely that you get a false negative. I do not know the likelihood of a false negative happening, however. I don't think it is extraordinarily common.

It could be an intolerance, not an allergy. If it were me, I'd stay clear of the food as long as it is causing a reaction. Doctors/allergists sometimes can't see the forest for the trees when it comes to food intolerance. The idea of "If it isn't an allergy, he can have it" just doesn't pan out in reality. Our DS has horrible diaper rashes as reactions to several foods but no allergy to any of them.

He may grow out of it so you could trial it every six months or so. I'd also do a blood retest at some point (maybe 1 year?) just to be *sure*. The instantaneous reactions make me think it could be a missed IgE allergy so I'd still be very careful - the blood tests aren't 100% reliable.

it's FAR more common when a person is on allergy meds. my allergist won't schedule an appt w/ a patient if testing is involved for that appt if they're on allergy meds- need to be off for two weeks for testing to be accurate.. the only exception being cases where that's potentially dangerous; asthmatics are not expected to stop their asthma meds, iow.
agree with the rest...although i'd probably try a retest w/o meds if it's important to you to have the dx.

[MrsMcCullen07]

My son was tested in January of this year (blood test) at our family dr.s office and there he tested positive to Milk,Wheat,Eggs and other non food items so we were sent to the allergist and they saw us about 8 months later and DS had been without those items for 8 months obviously so they did the skin test and it showed he was allergic to Cows Milk , Soy , Eggs , and they did a test for Banana's and Pineapple b/c both of those break him out really bad and that same day they did a blood test it showed he wasn't allergic to anything but our allergy dr. told us just to try them andif he reacted stop since blood tests will not show positive unless you have the *allergen* in your body .. idk why sorry ... just follow your instincts s:

[ashleyhaugh]

thanks for the info guys.... i need to call the doctor back, and i think what i want to do is schedule a skin test for after hes been off the zyrtec a while... i think he said 4 days, but someone mentioned 2 weeks... i guess longer is better in that case, huh?

i definitly dont plan to give it to him though... my dad keeps asking well how do you know if you dont give it to him? because dairy is in EVERYTHING and he gets a bit more often than id like (which is never, lol) and i have to deal with the fall out.

xh gets ds for thanksgiving this year ( ) and i told him he better plan on cooking seperate food for him, because if i have to deal with the aftermath of a weekend of people feeding him stuff i will kill him

[kjbrown92]

It really sounds like an intolerance to me. My DD2 gets stomach upset and eczema from corn. And she had a intradermal test (supposed to be more sensitive than a skin prick test) and an intolerant test and both said negative. Reactions trump results. The GI doctor said to leave it (and all the other reactive foods) out for AT LEAST six months before trying it again to give the intestines a chance to heal and let the immune system re-set itself. Our allergist said 5 days off antihistamines (sounds like they all have their own ideas).