Mystery reaction... help!

[Alpanini]

My seven month old has IgE allergies to wheat, egg, tree nuts, sesame, chickpeas and aubergine (and probably more but we there was no more room on his body for the rest of the prick test) and a non IgE allergy to milk. Anyway. For ages he'd been having ready brek, CMPA milk and banana puree in a tube from lidl for breakfast. On Thursday morning he had one of the worst reactions so far... hives on the chest and very bad breathing.
I keep playing it over in my mind and it's driving me mad. Why did he react this time? Few other variables... he'd just got back from swimming (but was totally fine after -- doesn't have a problem with chlorine...). The other thing is that my husband may have given him his water cup that wasn't washed from last night (but as he was drinking from it it shouldn't have had anything allergenic on it...?). I'm not coping very well with the allergies and feeling very out of control and frankly, terrified. This isn't helping. Anyone had similar or knows what it could be? I can't get through to the clinic for more patch tests... been trying for days. :(

[Alpanini]

The puree may have been in the fridge for three days rather than two...

[Schroedingerscatagain]

There is an allergy link up between latex nuts kiwis and banana so perhaps the banana was the problem

Also unless the oats in the porridge were gluten free oats you could have wheat contamination

[Alpanini]

It's just weird cause he has it every single morning and it's been fine!

[Schroedingerscatagain]

That to me would point to contamination of the porridge, are you using a free from version? If not I would recommend using one

[Alpanini]

No, just normal ready brek. Is it possible for him to be totally fine with it and then suddenly not? I don't quite understand how it works!

[SoupDragon]

It's just weird cause he has it every single morning and it's been fine!

Isn’t that common with allergies though? They can develop with repeated exposure.