Spoke to the consultant's secretary to me who relayed the message that I should continue taking antihistamines if I thought they were working. That seems to suggest they are meant to work for this kind of allergy.
I took one last night because I needed a good night's sleep. It worked reasonably well but did not really make any difference because it still leaves those gaps in the brain, in memory. I think I did okay today but I cannot be sure. Tried to wake myself with tea and, later on with coffee, but I am not sure they did any good.
She also asked if a salicylate free diet was working. I said it was early to say as I had only had the information on Friday - but I thought the list of salicylate-rich foods seemed familiar. On that basis they will refer me to their specialist dietician. No idea how long it will take to get an appointment on the NHS.