Hive reaction query (known food allergy)

My DS has a "known" food allergy to eggs and treenuts (skinpr!ck tests through RCH) and has avoided them since about 8-9 months (exposure through EBM only).

He was accidentally exposed to some egg on Sunday night as my IL's had fed their dog a raw egg 10 mins before we arrived (:wall: yeah don't get me started on THAT!). We know the dog licked his face and suspect the dog also may have licked his hand or even a potato chip that DS ate, hence he may have ingested some "eggy" saliva as well. He came up in some lovely hives (face and neck) and we gave him zyrtec as prescribed by RCH. We later realised that there were hives all over his legs as well (hadn't fully realised what was going on at the time!). On monday morning the hives had cleared... but Mon arvo they were back in force, so we took more precautions (just in case) - bathed (hadn't done it the night before :doh:), changed bedclothes, PJ's etc. This morning the hives are still on his neck and on his legs instead of very blotchy hives on his inner legs/groin he has them outside his legs (entire length) but they look more like spots than hives IYKWIM. So I gave him more zyrtec. The spots/hives are still there but quite faded now.

So what I'm wondering is - is this typical for a reaction to last for this long? It's been a full 48 hours now, but in the past when he's had hives it's been relatively short-lived, or his eczema has just flared up. I'm surprised that this reaction seems to be continuing. Plus I don't want to give zyrtec automatically, i'd rather wait and see if he's still showing symptoms. I couldn't see any other visible symptoms and he hasn't been too distressed. He's getting over a cold so has a cough and noisy breathing (he's always a noisy breather) so it's been difficult to say if there's been a respiratory impact. I've got a doc appt tomorrow arvo in case it still hasn't settled, but was keen to know if others had any similiar experiences or any wise advice?

TIA,
Belfie

Hi, I hope his hives have cleared up now.
A few years ago my daughter had a reaction to strong food colourings (in dairy snacks) and came out in hives. It spread everywhere and took 4-5 days to clear with regular antihistamines. At the time she had a cold and the doctor said it may take longer because her body was fighting hard already to clear the infections and then in come the hives which added to the fight.

It could possibly be the same case as your son (or the doctor I saw may have had no idea). If it were me I would continue with the zyrtec until you see he doc and go from there.
Good luck, I hope he clears soon.

Thanks for your reply SJL. I ended up continuing with the zyrtec everytime I saw more hives. It took just over 48 hours and then settled (just BEFORE we were going to go to the doctors - of course!) so I didn't end up taking him. It's interesting what the doc said about the cold impacting the recovery time though. I didn't realise that it could take so long for the reaction to settle down.

Thanks again :)