I've had a couple of Labradors over the years that have developed lick sores. The lesions that these dogs have had have been small oozing areas on the front part of the forearm or foot. The real name for this condition is a lick granuloma. Generally, dogs who develop these lick sores are bored. Some may suffer from separation anxiety. What happens is the dog will start licking the paw or foreleg over and over, gradually wearing away the hair and the skin underneath until there is a sore area. It's a similar motivation that causes horses to crib or weave in their stall. It's also possible that these are a result of an allergic reaction that results in inflammation which triggers the dog to lick at any area nearby. It has also been reported that hypothyroidism can play a role in Lick Granuloma. It would be good to test T4 levels as certain lines are prone to hypothyroidism.
Treatments for lick granulomas include laser surgery that removes the sore tissue. For the most part nothing works though because it appears to be a psychological compulsion to lick and chew the area. Some anti-anxiety drugs have been used with mixed results. Cortisone injections have also been used and may alleviate the itchiness. Cortisone cream can be especially useful. One solution that has been useful is long-term use of antibiotics. It may take from 3 to 6 months though to make a difference. If lick sores develop, consult with your vet about what kind of treatment is advised to keep the sore from getting worse.