Standard Poodle Skin Problem

Question
I have a 3 year old WONDERFUL Standard Poodle that has had no previous problems.  In the last two weeks she has lost a LOT of hair and has a place on the back close to her rear that she has started chewing until it bleeds.  I brushed her and when I did I thought she was more like my Pomeranian because so much hair was lost.  There are some patches on her that seem to have little "white" dandruff looking particles and when I find them and try to see what the white particles (flakes) are, the hair falls out that is in that spot.

Any suggestions?

Answer
Hello Donna,
It sounds like your dog has a Hot Spot on her backside.  Hot Spots can be caused from about anything; ie Allergies, Fleas or Illness.  Allergies tend to be a major cause of hot spots and dogs can be allergic to the same things as people.  
Is there anything that you can think of that you might have changed, or something new that you introduced into your dogs enviroment? (such as cleaning supplys/detergents, new/switched foods, yard treatments)
If she has fleas (or even one flea) and is allergic to their bite, that can trigger a reaction which can cause her to bite and itch her skin like you described.  

You can treat her for fleas, and you can also give her a Benedryl tablet in the evening to help keep her from itching.  You can also apply Benedryl cream on the spot she is biting at if you think that she won't lick it off, to help with the irritation.  

Give this a try and let me know how she is doing.  If she is still having problems, we can look into other forms of treatment.  

If you have other questions for me, please feel free to ask.

Thanks for using AllExperts.com,
Kim