That is an excellent question, and one that would best be answered by your primary care doctor
. In general, there are several reasons that your leg may have this sharp burning pain but I will need more information, which is another reason that your primary care doctor is a good resource because he or she can get a complete history and physical examination on you to determine the cause. Here is some information that would be helpful to know to make the diagnosis. Is it the entire leg, or just a small area of the leg? Have you had chicken pox before, as this is sometimes how people describe the early stages of shingles, although they are usually not as young as you are. Do you have any weakness in your leg, as sometimes this can be associated with a nerve entrapment in your leg which can be associated with it. It is difficult to know the cause of your burning leg from the limited history given, but a primary care doctor or pediatrician will be better able to elucidate the cause of this as he or she will be able to get more information. For this reason, it is suggested you see a medical professional as soon as possible.