Allergic reaction to Bleach

Hey all!

I've recently had another allergic reaction to hair bleach. Using the same bleach (L'oreal Platine that is now apparantly Studio) and developer - I've had a reaction where my entire skin goes super itchy and red (embarassingly, the rash starts from my upper legs and knicker line??) - spreading to my face within minutes.

Now, the first time this happened, I had an allergy tablet and a cold shower, immediately washing the bleach off and it was fine.
All I did differently was sit near a radiator - I get super cold easily so radiators are my favourite places to sit.

Then the next time we bleached I took an antihistamine before bleaching and no reaction.

Then I left my hair brown for about 4 months and I recently decided to go back to pastel peach and an undercut as a treat. Again, we bleached and I was sat in an armchair, wrapped in a towel and playing on my phone when I realised I was itchy again. I didn't take a tablet beforehand, and I guess I was warm and cuddled up on a chair but nothing like the radiator. Lo and behold, 20 minutes later my skin went pink in less than three minutes and my breathing became slightly (minutely) difficult.

I've been dying and bleaching my hair consistently since I was 13 years old - I'm now 25 hah.

Had anyone else ever had a reaction to bleach? I'm thinking of changing the bleach to Redken, Wella or something else.

It's irritating because It's such a recent thing to happen to me. Need to get it finished tomorrow, so I'll take an anti-allergy tablet beforehand and sit infront of a cold fan - we're not bleaching the scalp further, just the ends that are still too dark to colour over.