How common is it for a skin prick test to show nothing

[longwaytogo]

13 yr old dd started reacting to nuts at christmas. She says that she itches all over, her chest goes tight and her throat feels like its closing up. The GP put her on piriton which helped the itching but did nothing for her throat so was then put onto loratadine which works.

Been to see Dr at hospital this am and did some skin prick tests for peanuts, hazelnuts, walnuts, soya, house dust mites and possibly another that I can't remember but no reaction showed. They have now taken a blood sample to see if that shows anything. He says if that shows negative then he will bring her in to challenge her.

Does anybody else have any experience of this, is it quite common not to react to the skin prick test.

Sorry for the ramble but just hoped that today would bring us some answers.

anyone have an answer please

Sounds strange to me,ds reacts to skin pricks,he is allergic to tree nuts.
Maybe there was something on the nuts that she reacted to.

Its not just when she eats 'nuts' its when she eats things like chocolate spread which has hazelnuts in it, celebrations chocolates, some cakes we had in france that had marzipan bits on. pain ou chocolat, amongst other things.

She is now thinking like she does about other things she has wrong with her - aching joints etc

I'm sure she hasn't but has she been having any antihistimines in the last 7 days? This can sometimes give false negative readings.

no she stopped taking her tablets about six days before, one leaflet said three days the other said 5.

She got up this morning and said she felt sick. Wish I could work out what is wrong with her.

I'm not an expert but am having my LO tested as part of research study on Friday. I think that skin prick testing is less accurate than RAST (blood) tests especially as you are comparing a skin reaction to a known oral reaction. Obviously neither is 100%. Many sympathies though, I am allergic to hazelnuts and walnuts (but not peanuts or any other nuts!)

thanks wtwta thats what i wanted someone to say

I'm afraid that doctors have not yet agreed on which is the best type of test. DS had a ELISA test that showed he was intolerant to 90% of the allergens tested. Then he had a RAST that confirmed some of the previous results and showed he was NOT allergic to wheat and allergic to milk between other things, and today he finally had the prick tests which showed that he is indeed allergic to wheat but not to milk! So I guess that the accuracy of them may depend on the characteristics of your child's own allergy, and the likes and beliefs of the doctor treating her.