Accepted Answer

Hello,
The paws and legs is the give away. I am highly suspicious for either an environmental or food allergy. Now, be careful with flea shampoos. They are harsh on the skin and if you leave any residue (don't wash out thoroughly enough), will exacerbate the irritation to the skin.
Stick with topical flea control products for fleas, like Frontline, Advantage, Promeris.

So, i'm going to load you up with a bunch of info about both environmental allergies (atopy) and food allergies. Use this info when you bring your pet into the vet so you are prepared for what treatment they may offer.
Feel free to even print the treatment alternatives and run through it with your vet.

So, to rule-out food allergies you need to do a diet trial.
Summary: The primary protein in most dog foods is lamb, chicken, or beef. The primary carbohydrate is rice or corn. So, we need to change both. The most popular alternative diets are Venison and Potato, Duck and Potato, or Fish and Potato. It is available in prescription formulas (i.e. Science Diet D/D) or you can find some similar foods at the big pet stores like PetSmart or PetCo. Keep in mind, holistic or all-natural foods are not necessarily any better when trying to remove a food allergy. Chicken is chicken, and rice is rice. When you perform a diet trial, you must stick with the food for 2-3 months to see if there is any benefit. No other treats or human food can be given during this time period.
http://www.petplace.com/dogs/food-allergy-in-dogs/page1.aspx

Also, definitely read about ENVIRONMENTAL ALLERGIES (atopy). Some pets, suffer from both environmental and food allergies:
http://www.petplace.com/dogs/atopy-in-dogs/page1.aspx

If you want to actual diagnose what in the environment may be causing the allergy, you can do an allergy test. Now, you don’t have to shave half the body and do the old grid test on the skin. There is now a rather good blood test that looks for allergies to weeds, trees, grasses!, molds, even house dust mites. You can read more about it here:
http://www.varlallergy.com/index.html

Now, in addition to allergies, there are also some other common causes of skin problems or secondary infections that can occur:
Mites (demodex or scabies). Demodex is not contagious, however, scapies or sarcoptic mange is zoonotic. So, keep in mind, when ever someone mentions mange, it is important to distinguish between which mite. To diagnose if there are mites, your veterinarian can perform an easy skin scraping test in the hospital. It is not always 100% accurate, but a good start. It can be difficult sometimes to scrape out the mites.
Demodex:   http://www.petplace.com/dogs/demodicosis-red-mange-in-dogs/page1.aspx
Scabies:       http://www.petplace.com/dogs/sarcoptic-mange-in-dogs/page1.aspx
Skin scraping: http://www.petplace.com/dogs/skin-scraping/page1.aspx

Secondary yeast or bacterial infections (very common)
Frequently, the skin will be inflamed, have an odor, and/or oily component.
http://www.petplace.com/dogs/skin-discharge-or-odor-in-dogs/page1.aspx


TREATMENT OPTIONS (A small representative list)
Steroids. Veterinarians will either give an injection that can last from hours to weeks, or send home oral steroids like prednisone or dexamethasone.
Antihistamines. A prescription of hydroxyzine is common. Sometimes, over-the-counter Benadryl will help.

Benadryl can be given at a dose of 1mg per pound of body weight. Keep in mind, Benadryl tablets and liquids come in different sizes. So, an approximately 25 pound dog can get a full 25mg tablet or a half of a 50mg tablet. I usually avoid the liquid Benadryl in larger dogs (you would have to give too much of it). You can give Benadryl every 8-12 hours.
http://www.petplace.com/drug-library/diphenhydramine-benadryl/page1.aspx

Essential fatty acid supplements. Definitely, if you plan to give an antihistamine long-term,    
combine it with an EFA supplement. I prefer the veterinary products dosed for pets.   Your vet
should carry a product on their shelf, or over-the-internet you can look for Aller G3, 3V caps,
EFA-z, or Derm caps.
Some vets use a product called Temaril-P. It’s an antihistamine with a low-dose steroid built into
the same tablet.
Atopica. Neat stuff. Can take a few weeks to be of benefit. Not the most cost-effective, but can
be incredible for allergies when the above does not work. Read the link below for more
information.
http://www.us.atopica.com/indexConsumer.shtml
Your vet may also carry some special sprays or shampoos for the skin. Some contain topical
steroids with antibiotics. Others contain analgesics to comfort the skin like “Relief Shampoo” and
“Relief Spray”
Lastly, oral antibiotics or antiyeast medication, if indicated.

Good Luck
Dr. Andy

Expert:	DrAndy
Pos. Feedback:	100.0 %
Accepts:
Answered:	8/17/2009

Veterinarian

UC Davis grad, Interests: Internal Medicine, Dermatology, Pain Control, Emergency