itchy back (Beagle)

Question
My Beagle is 4 years old.  Once every few months he starts to itch on the lower back part (near his tail (Dog's back).  Today I noticed while looking that his skin is redish and I guess from biting himself so much he has a scab which bled while I was grooming him.  He seems pretty miserable, and he also vomits every day (maybe because of swallowing his hairs?).  Otherwise he is healthy, and he eats well.  Last time I had a spray for this type of itching and it helped.  Could it be eczema?  

Thank you.  

Answer
Dogs really do not get eczema.  Probably something caused the itching, like an allergic reaction to a pollen or an insect, and the dog self mutilated himself.  This type of lesion requires systemic therapy.  Sometimes just a shot of cortisone will help relieve the itching.  Most cremes or sprays will not help.