Hello, My name isXXXXX will try and help you the best I can.
First a few questions: Has the dog ever had skin disease before? Is the dog on any flea prevention? Is the dog on any medications right now? Does the dog have any other medical problems? Has your dog been seen by a vet for this problem?
Also, does your dog seem itchy (is she scratching a lot, licking paws a lot, scratching at ears, etc)?
conditions before she has had drops on back of neck for fleas she has been to the vet she is not itchy
How large of an area is showing this problem?
her sides about8in by 5in both sides one at each shoulder under her tail at her bottom and virginw
small patches on her back
Any red bumps in those areas?
There are many causes of skin disease: fleas, allergic skin disease, mites, bacterial or fungal infections, and metabolic diseases. I think your dog needs to see a vet so they can take a sample from the skin to see what is going on. This can be as simple as a scrape of the skin or a swab. I also think blood work is necessary to make sure this is not due to a systemic disease.
Please let me know if I can provide any more information for you. Thanks. Please don't forget to rate.