Hi there and thanks for your question. This will be a hard one to answer without seeing your boy, but I can give you a few ideas.

It sounds like it may be an infection of some sort. If he is an outdoor cat, it is possible he has gotten into a fight and these are wounds from the fight that are infected. Even as an indoor cat, skin infections are still possible. While polysporin/neosporin applied 3 x daily won't hurt, most skin infections need a good course of oral pills prescribed by your veterinarian.

It is also possible that it is an allergy to something. Some cats will get a localized area of scabs and pustules as an allergy to food, an insect sting or sometimes we don't know what. If this is the case it may go away within a week, but if not he may need a steroid shot from your vet.

Another possibility, although less likely is ringworm which is a fungal infection.

I would recommend to keep an eye on it for now. If it is getting worse, or if there has been no improvement in a week's time then a vet visit is in order.

I hope this information helps! If you have more questions regarding this problem, just hit reply. If I am online I will respond right away. Otherwise I will respond as soon as I come online again. Or, if my answer is sufficient, then please hit accept. Thanks!

Dr. Marie.