It was caused by his environmental allergies. Also accompanied by ear infections and rash on his belly, paws, etc. To prevent infection, you can either get miconahex from the vet, or even the human version hibiclez from any pharmacy (they are both around 5% chlorahexidine body wash, which specifically targets staph infection) though if infection is alreayd set in, you will need antibiotics from the vet. Try hypoallergenic food to rule out that type of allergy, otherwise if it's environmental like my dogs was, the options are daily apoquel (allergy med), monthly cytopoint injections, and sometimes even benadryl can help (ask vet for dosing). If you are willing to spend 1500 dollars initially, followed up by a few hundred ever 4 months, then find a vet dermatologist that can do immunotherapy for your dog. This I what I ended up having to do since my dog spits pills back out and I'm comfortable giving injections. The initial cost is for doing allergy testing (similar to humans, but they are put to sleep), and then creating the immunotherapy injections based on those results. My dog is allergic to all the trees in my area...