Cat compulsively scratching and licking?

Zooming out so trying to be quick... I've been told sores on the face often mean food allergy. If those are dry food, try a wet that doesn't have cereal. If you are in the UK 'Clic' brand from Sainsburies/Waitrose is a good one to try. My girl had this symptom form milk/cheese. Food bowl could also be responsible: see if you can find a shallow gl or ceramic bowl/plate/saucer that fits inside the automatic feeder. If he's an inside cat, I'd leave off the Frontline for now. My girls had fleas only 3 times in 19 years as inside cats... (and two of those times they'd been out briefly) Allergies can be to anything, including something that's been fine before, so keep trying! Good luck!