Skin sores

Question
Our dog is almost 15 years old and has had chronic skin allegeries for at least half of his life.  In the past several years he has developed what our vet refers to as "warts" primarily on his back and head.  He also has an open sore on the top of his head that our vet does not seem too concerned with but it leaks and causes the hair around it to mat and cake.  I have put an antibiotic ointment (baciderm?) on it in the past, but it has not helped.  We just recently gave him a haircut and the sore seems to be worse and in fact had a terrible odor to it when I cut the hair that had matted around it.  I reapplied the antibiotic, but I am concerned as to whether I should bring this back to the attention of our vet or not worry about it.  Our dog is a mixed breed of terrier and maybe some poodle.  He does not shed and therefore if we do not keep his hair cut, it does mat.  Once again he will be 15 in October and he does also have arthritus and takes medicine for that.  
I would appreciate any suggestions or comments.

Thank you for you time.


Answer
These skin gfrowths are very common in older dogs.  Any of them weep because they are called sebaceous adenomas.  These tumorous glands secrete and there can be quite a bit of accumulation on the skin.  You can ask your vet to remove these.  In my practice I have a laser and I can vaporize these tumors quite easily with minimal surgical risk and discomfort.