Blood test result help!

[Christmascaker]

Hello,
I’m hoping someone may have experience that can help us.
My son had a reaction to a slightly runny boiled egg last October. Hr was violently sick pretty much immediately after eating it, he’s also had eczema from 2 months.

We saw the gp and we’re advised to avoid egg until we saw a paediatrician.
We eventually had a telephone appointment in June and had blood tests done in August.
The letter we received said blood test showed no allergy to foods they tested for, that his overall total IgE was low at 17ku/L.
We were told to reintroduce egg in baked goods. As soon as we’ve done this, he’s had a big flare up of eczema. Does anyone know if this could be related? Since the flare up I’ve been looking into the results and google tells me 17ku/L is a high result?!
Im also confused, can the blood tests come back negative but a reaction still be possible?

Rather confused, thought some of you wise experienced people may be able to help!

I'm no expert on this but from what I understand, the total IgE looks at the allergic response in the body not a specific allergy. Googling just now, in an adult the normal range for a total IgE is 0-75 ku/l (dont know about for children).

It does sound like your son may be reacting to egg in some way though so I think you should probably try and speak to your gp again.

I think the blood tests also show the likelihood of having an allergic reaction rather than necessarily the strength of reaction. So you can have a borderline positive result for a particular allergen but still have a big reaction.

As I say I'm no expert. My DD is severely allergic to milk (needs to carry an epipen) but shes 13 now and on the basis she wont outgrow the allergy now we haven't had blood tests for a few years

The normal range for total IgE varies depending on age, if I remember correctly 17 is within normal for all bar young infants. However, a normal total IgE doesn't rule out an elevated specific IgE result. The reference range for total IgE is different to that for specific IgE.

I understand it as Minty does, total IgE looks at the big picture and is usually elevated in atopic people. And a higher specific IgE doesn't necessarily correlate to a more severe reaction, only a higher likelihood of an allergy.

Has DS had specific IgE bloods &/or SPTs? There's also the possibility the allergy isn't IgE meditated.

Thanks for the advice 😊 he had some cake this week then was really sick a couple of hours later so we’re going to stop anything with egg again until we have our follow up appointment. The impression I got from the paediatric doctor was that because the blood tests came back ok he didn’t have an allergy but it seems that may not be the case. She did she she would normally refer him for an “egg challenge” in hospital but they’re not doing this at the moment due to Covid.