Susanne Runge in Australia has asked if scabby potatoes are edible: Is it ok to eat potatoes that are affected with common scab?
TopVeg always peels the scabby bits off, but otherwise eats the potatoes as normal. The disease is only skin deep and the eating quality is unaffected.
Common scab is caused by soil borne bacteria. Cooking the potato will kill the bacteria. Hope this helps!
Click these links to read about corky scab in potatoes & common scab in potatoes