Histamine control didn't react in SPT

[IowaMom]

Yesterday I took DD for skin testing for PN.  It had been 4 years since the last time we did SPT.  The doctor said that the test was not valid because her histamine control barely reacted (it made a very small red bump, but the dr said it should be a lot bigger than it was).  She takes a half of a children's chewable claritin daily.  The appt letter said to take her off 5 days before the test, but we took her off for a full week before the test.  She is on no other medications.  Has this happened to anyone else? Could there be another reason that the histamine didn't react??

[rebekahc]

Bad/outdated serum?  Not pricked hard enough?  Does she take any other meds that might have affected the result?

So, out of curiosity, what was the PN result?

[IowaMom]

When they realized the histamine wasn't reacting, they did it again- and it still didn't react.  She takes no other meds.  We do put lotion on her (a pretty thick Aveeno lotion) but they wiped her arm with something prior to the test so I wouldn't think that would matter.  Her PN was 7mm, compared to 16mm 4 years ago.

[rebekahc]

How frustrating that the doctor said the results weren't valid!  It sounds like her skin was plenty reactive to the peanut serum.  What about doing a RAST test instead? 

[IowaMom]

She did a RAST back in Feb and it was less than .35, which is why we had her skin tested again.  When we did SPT 4 years ago, her level was .45 but her SPT was 16mm.

[YouKnowWho]

It is always a gamble if DS2 will react to the histamine prick.  I have finally learned that the half life of meds in his system is WAY longer than the average bear.  So I try to do SPT testing with at least a three week break in antihistamines.

[IowaMom]

YKW- we go back July 31st.  They said to hold off on the claritin for 2 weeks, but maybe I should go 3 just to be safe.  It's in the middle of July, so her allergies shouldn't be that bad then.  Ugh!

[YouKnowWho]

It's why we have to time DS2's current testing in July/August.

We are in the midst of mystery right now but he cannot be off antihistamines long enough to figure it out (not even sure it's food related).  Allergist wants to wait UNLESS we have another flare up.  He thinks it is probably temp related.