Skin problems are
multiMulti symptom cough and cold
Multi vita bets and fluoride and iron
Multi-betic
Multi-day
Multi-day plus minerals
Multi-day with calcium and extra iron
Multi-day with iron
Multi-delyn
Multi-delyn with iron
Multi-symptom nighttime-factoral and very frustrating since they are so complex.
For skin problems there is usually a
primaryPrimary amyloidosis
Primary biliary cirrhosis
Primary hyperparathyroidism
Primary insomnia
Primary lymphoma of the brain problem and often one or more secondary problems.
Primary problems include mites, such as scabies and demodex, flea allergy dermatitis, food allergy dermatitis, ringworm, atopy (environmental allergies), and others.
If your dog becomes itchy from one or more of the above and scratches and bites the areas, bacteria and moisture (from his mouth) are introduced into those areas. The bacteria causes a secondary pyoderma (bacterial skin infection), and the moisture sets up the right environment for a yeast pyoderma (yeast skin infection).
Obviously you will need to take her to the vet to have this sorted out.
Your dog's vet may need to perform a variety of tests, which can include: a skin scraping, allergy tests, fungal assay, cytology of any skin secretions, even biopsies, and more. Depending on your dog's age your vet may want to perform thyroid function tests and other blood tests. Since skin problems are multi-factorial, many tests may have to be performed, or, you may be lucky and the vet finds scabies, for example. Scabies can be successfully treated these days, it just takes a long time to resolve.
Allergy testing can be expensive, but allow your vet to perform the less expensive tests first. Allergy testing can be performed later if you cannot afford it now.
Treatment will depend on what your vet finds and it may consist of oral anti-bacterial medication, anti-fungal, a steroid or other anti-inflammatory, anti-histamines, a change of diet, shampoos, anti-parasite medication (if scabies, demodex or fleas are found), and more.