how often does the cat lick her legs and tail. I had this cat which has been stray for a while i suppose and she keeps licking her legs and tail. Is she infected ?
Cats are very clean and will groom themselves. Some cats will be aggressive with grooming for one reason or another and become Obscessive Compulsive and over grooming. In some cases a cat will groom until there is not hair left in an area. This can be a result of stress or another issue.
Grooming has nothing to do with infection. Cats are avid groomers. If you are caring for this cat and feeding it, you will want to watch for over grooming. The cat may need some medication for Obscessive Compulsive behavior/stress(Psychogenic Alopecia) to help with her grooming issues. http://www.cat-world.com.au/over-grooming-in-cats
I hope this explains what may be happening with your cat. You may want to try and supply some stimulating toys to see if that may help keep her mind off grooming.