Please help this Poor Little Dogie!

I know this is not relevant to this blog, but some of you may know that I have a 2-year-old female Maltese named Babie, and she weighs about 4.5kg.

This post is mainly to seek expert opinion, solutions or suggestions from public regarding her skin condition.

My little dog has been suffering from skin disease since December 2010. Due to severe itchiness, Babie keeps scratching and biting. Thus, the fur at her legs started to fall off, and it is getting extensive.

The red patch at the tail is due to her bite mark.

Some of her fur are growing, some are not. 
This condition keep repeating like a vicious cycle.

Her back is so smooth. Fur-less.

Patchy fur loss.

We sought treatment from veterinanian, and was diagnosed as yeast infection. Here are some of the summaries regarding the treatment that I have given to her, however, none seems to work.

1) Started on T. Griseofulvin 50mg OD for almost 2-3 months.

2) Concurrently using topical Miconazole(anti-fungal) and steroid cream.

3) Malaseb Shampoo, used every 3 days, soaked for 10 minutes before washed off. Used approximately 1 month.

4) Currently, she is on T. Ketoconazole 50mg BD, 3rd week of treatment. However, skin does not seem to improve, and extending from back leg to neck now.

5) Regular Spot-on and collar(Bayer).

Now we keep her on a tiny shirt to keep her from biting and scratching. But condition remains the same.

I would appreciate if you can offer us any opinion, your past experience, or any good website or links that might help my poor little dogie.

Please kindly drop us a comment below. Appreciate your time in reading.