According to Dr. Laura Robinson, DVM, itchiness is the main symptoms of skin & coat issues. Dogs will often start scratching and licking themselves over and over again certain places. Flaky & red skin, infections, scabbing and redness in other places are all potential signs of underlying issues.
Skin & coat issues can be related to an unhealthy diet, such as having micronutrient deficiencies like zinc or omega-3 fatty acids. They can also be caused by genetics or allergies. An underlying endocrine issues, such as problems with the thyroid or adrenal glands can also make your dog more prone to skin infections. It can also be related to breed.