the hair of the dog that bit you?

[Eway]

What does "the hair of the dog that bit you" imply? As I read:

"Everyone keeps asking, "What's the cure?" - The cure is the hair of the dog that bit you! When panic starts, ..."
(from http://panicdisorder.about.com/od/sh...smallthing.htm)

I also use the key words to find related contexts by google and found many articles with this expression. I don't think this means its literal meaning but sitll can't figure out what it implies. Can anybody explain to me? Thanks!

[rewboss]

It's usually used in reference to too much drink. If you have a hangover the next morning, some people will tell you that the best cure is to have a drink. The "dog that bit you" is all the stuff you had to drink last night. So, "Have a hair of the dog that bit you" usually means, "Have another drink and your hangover will go away."

You could extend that to other contexts as well. In the article, the author says that the way to deal with anxiety is not to try and avoid anxiety, but to face up to it. That's not quite what the idiom means, but it's close enough.