thanks everyone for your replies.
luckily for me at the mo my kids have forgotten about the fact that I had a 'sore arm' recently and no longer ask me constantly to see it (not a problem while it was being dressed!!). So that situation has abated for now. But on Monday and Tuesday I was asked about scratches I have on my face. They have been there for at least 2 months but I have not been questioned about them before... all I said was that I had been scratching and they had gotten infected, pretty much the truth and accepted straight away.
I have taken on board everyone's advice, printed this page, and have filed it away for when I need it
thanks again