Hello,
Bloody nose and swollen face along with an odor from the face indicates infection. I suggest you an immediate evaluation from his physician as he needs topical and oral antimicrobials and dose is specific for pediatric age group.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.