Agnesrsn

My are not working either. I received NOAs letters on 8th but I still have an errors on their webpage. It doesn't recognise my case numbers.
I guess/hope it will start working at some point ... 

I do not have a solid information but I do not think that allergies is something they would care much about. At my exam they only asked if I had any and what food I was allergic to but they were not interested on how severe it was.
At the medical exams they want to check if you are not spreading anything contiguous and if you are not going to become a burden to the USA social care due to your 'health disabilities'. Again this is something they told me but I have no written links or docs to back it up. Either way, my advice is that, you should be honest about the facts with medical examiner and only give exact information you will be asked about. It is often good approach and avoids any potential misunderstandings to be formed. No extra details/stories is needed if they do not ask you for it, especially if you worry about it. 
Try not to worry too much (I know is easier said than done) as you cannot change anything and you need to go through the exam. My exam was quite good, thought it was weird process/to be there, everyone was nice and helpful, hope all will go well for you too. Goodluck!