Allergy London - Professor Adam Fox. We saw him at the Hertfordshire clinic but they have a clinic in London too. They were excellent - couldn’t recommend enough, and he’s one of the leading allergists in the UK.
@Victoria funny I have been looking at them. Thought they must be good if they are at Great Ormond Street
Medical diagnosis in Wembley apparently does walk in blood tests. I've not been/used them, but the lady who runs drought.secret on Instagram (amazing creams!!) used them for her daughter.