skin condition

Have a Harlequin Great Dane who just turned a year last month. He has a really bad skin condition that he continually scratches and licks and does it to the point where he is raw. Hes got patches of hair that is missing he looks like a wreck. He eats Diamond food. Doesnt get table food. He had been treated for whipworm and now gets monthly worm pills. The doctor is trying to use the steroid shots which works if he gets them every month. But it takes a few weeks for his hair to grow back.The vet is beginning to think hes going to have to do a skin biopsy. Any suggestions?

[Aleda M Cheng, D.V.M., C.V.A]

If the steroid injections are effective than the problem could be allergies or autoimmune disease.

A biopsy may be a good idea, but if you are hesitant about the idea, the following options could be tried:
Skin scraping to check for demodex, scabies, or other mites.
Culture and sensitivity to check for bacterial or fungal pyoderma
Fungal Assay
Hypoallergenic food trial
Try the following medications:  Atopica, antihistamines, and oral steroids, antibiotics and antifungals for the secondary infections.
Allergy testing (skin testing or blood test)
Desensitization