DD3 had her pre school boosters 9 days ago. She had a small patch of raised rash on each of her hips at around day three. Today she has developed huge hives all down her trunk, under her chin, armpits, bottom. I watched them grow and spread visibly within minutes and gave her a dose of piriton syrup to no effect. Then her left eyelid started to go puffy and swell 
DH has whipped her along to A&E just now. She seems happy and chatty if a little pale, but I am worried about how quickly it escalated and frankly, shitting myself.
Has anyone experienced this? Does anyone know what they will do at A&E? I'm panicking in case it develops into a severe reaction. I just want to be with her but I have 3 other DC asleep in bed 