Hi
I am sorry to hear that Bruno has been poorly; I am sure he will recover eventually though once he shakes off this bug.
The scratching is a tricky one with the wound being under the chin. you could try dabbing the hardness with a little olive oil to alleviate the itching. Also, make sure Bruno's claws are clipped so that they will be less sharp if he does scratch. You can get an ointment from your vets to alleviate the itching, but I think it is a steroid cream.
The obvious advice is to fit Bruno with an Elizabethan collar, or to fit the little plastic caps over his claws until the wound has healed (called soft paws I believe)
Good luck, and I hope Bruno makes a speedy recovery!