Yes I agree. Demodectic mites is a possible cause here. The best treatment for mties is actually using one of two flea preventatives (Bravecto or Nexgard), which are also labeled effective against Demodectic mange. You can only get these products through your vet in most cases, so waiting to schedule an appt with your vet is the only way to begin treatment for Oscar. The vet will want to confirm mange with a skin scrape test. Another possible cause is skin allergies, which can also be treated for with prescription medication (i.e. Apoquel, Cytopoint, Temaril-P) through your vet.