Just looked at the photo. LOL
Agree, could be staph or some type of cellulitis.
Probably needs a culture done.
Whatever, make sure you keep your hands washed.
Looks like Staph Infection to me.....Oral antibiotics from your Vet are the first line of treatment.......Karla
What flea medication did you use? Was it a topical?
What food are you feeding? Dies it have corn or other grains in it?
Have you put anything on the lawns recently?
The vet should be able to diagnose. Allergies are the likely source, that is there is something in his diet or environment causing the problem.
If there is not odor it most likely isn't yeast.. a simple medicated shampoo may be all that is needed. You may want to try one of the over-the-counter dog shampoos for itchy skin. Buy a small bottle just to try.
Hope you find a cure, allergies can be very difficult to identify/cure.