skin condition

i have a male pekeingese who has a skin condition. he licks his skin and it matts his hair into clumps where when we try and cut it he screams any ideas. we have shaved his back end once but now we cant get near the spot or even try to shave him

The first thing I would try would be a different type of food for him. A lot of dog's have allergies to wheat and especially corn so try to avoid them. A high quality dog food goes a long way in preventing skin problems.