asthma
Many,many years ago I was stupid (honest?) enough to admit that I suffered from Hayfever on my OASC application. Unsurprisingly, they wrote back saying "sorry, woukld you like to apply for another branch (or 3) other than aircrew? I went back to the specialist who had done my original allergy tests - couldn't get an appointment so simply sat outside his office for hours and then "doorstepped" him - apologising profusely but explaining my predicament. Long story short - he wrote to the RAF on my behalf, explaining in detail the tests he had done - they considered it and then sent a young CB an invitation to OASC for pilot aptitude tests. The rest, as they say, is history.
My point in telling you this ? if you want something enough then go for it - simply by doing so you are displaying your determination to thiose people whi will make the ultimate decision
Good Luck.