This is a common symptom of allergies in dogs.
Paw licking, ear itching and skin chewing are all often signs of allergies. You may see red staining to the fur in the licked areas or raw spots where the dog chews itself to the bone.
The skin itches from allergies, the dog licks and chews trying to soothe the itch, making the skin raw and allowing other infections to set in which may itch even more.
It is believed that the chewing of the dog's own flesh releases chemicals in the brain helping to control the feeling of irritation the allergy produces.
You can read about allergies and dermatitis in dogs here to see among other things that its not easy to pinpoint the problem allergens
Dogs can develop allergies to foods, and to inhaled items, and contact allergens such as rug cleaners, cedar beds, or chemicals including lawn chemicals or even flea bites.
You might want to try a different dog food that has no ingredients the same as what you feed now. Diets of Fish and Potato, venison, or rabbit etc. where the protein source is new and there is no grains in the food can work for many dogs for example. Wellness, Natura, Blue Buffalo, California Natural, Eagle all may have a formula that might work for your dog.
You might want to see if some plain Benadryl helps with the itching. A common low dose is 1mg per pound of dog every 12 hours.
Or you may want to consult with your vet and consider doing allergy testing.
You may want to try a Chlorhexiderm shampoo from the pet supply store in case part of the problem is a bacterial skin infection.
This breed is also known to have low thyroid level issues and that can trigger skin allergies and ear infections. The vet can check for that with a blood test.
If your dog is not on a flea prevention that might also help. Just one flea bite can make an allergic dog itch all over.
To sooth the ear, if the ear drum is not punctured by infection, you can see if your local pet supply store carries Zymox with cortisone. I've had good luck clearing up infections with that. You can read about it here
Hope this helps you!