Bald and itchy

Question
I just adopted a 1.5 yoa westie who was neglected so badly she pulled out all her hair. I was told it was due to a flea infestation, but no where on any of the vet papers she came with is there a confirm she even had fleas.  Most of her fur has grown back, but its like straw and very sparse on her belly and legs.  She is now continuously licking at the fronts of her legs and scratching her neck to the point it bleeds. She was checked by a vet at the rescue, and they put her on Zyrtec and hydrocortisone cream, but this doesnt seem to help at all and I dont like the idea of constantly applying a steroid. Oatmeal baths help short term and gently rubbing off the dry scabby chunks, but until the blood/allergy tests come back I won't know what the allergies are stemming from.  Can I put clothes on her to stop her from licking those areas past bald again?  She is eating Solid Gold food (Bison based), was eating Iams, but the change hasn't made a difference either.  Her skin is very thick and loose (wrinkled like a Sharpei almost), and her nipples are very big (she did have a litter and has since been spayed).  Will this change when I get this under control?  

Answer
Westies are one of the breeds that are highly allergic to many things. Allergy testing is probably a good idea for this pup and I would do a food trial with a different protein source than she is currently eating.   But I would first have her treated for sarcoptic mange with a dip in either phosmet or amitraz.  Your vet can do this for you.

Systemic corticosteroids or cyclosporine (Atopica) may be needed to get the dog's skin to stop itching.  There may also be a bacterial and/or a yeast infection in the skin that needs treatment.