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It could be a fungal or bacterial dermatitis, however, I would also consider a possible sarcoid formation in that area. Sarcoids are benign tumors that form on the skin. They can be flat or bumps. In this case, I recommend that you have a vet evaluate the skin condition and possibly take a skin sample for histological evaluation. If it is a possible sarcoid, you do not want to take any skin samples as this can make the problem worse, and thus, why a veterinarian would need to look at the skin for you. Hope this helps. Cheers
Thanks for the additional information,
Very odd, not too many skin conditions that spread like you describe and not cause hair loss. There is a juvenille wart syndrome that will cause several warts to form on the face but mostly around the lips. This could look like what you describe and will resolve on its own within a couple months. I would highly recommend that you have a vet out to examine it and possibily take some samples for analysis. It doesn't sound like one of the common skin problems. Best of luck.