<s>[INST] I have severe burning inside mouth below tongue on left side. This started post chickenpox in Jan 2007.Initially it was pin and needle pricking kind of pain. Now it is burning pain. Pain increases with hot, cold, sour foods.Pain also gets worse after eating food from that side. Please help. [/INST] Helloi have read your query.please mention your age. Once you have had chickenpox, the varicella-zoster virus lies dormant in your nerves and can re-emerge as shingles (herpes zoster). Shingles, which is characterized by a rash of blisters, can be very painful but is not life-threatening. Shingles is most common in people over age 60 or in those with a weak immune system. Before the rash appears, you will have warning symptoms of pain, usually a sharp, aching, piercing, tearing, or burning sensation. Common site is one side of the face, which may even include the tongue. Some people who develop shingles can also develop a condition caused postherpetic neuralgia, which causes the skin to remain painful even after the rash is gone. Another chances of burning sensation can be due to some oral habits like intake of tobacco in any form specially chewable. If that is so. Quit the habit. Shingles vaccine can reduce the risk of getting shingles among people who are over 60 and have had chickenpox. Some antiviral Chat Doctor.  I suggest you to consult a physician first and get everything checked. Hope this ans helpsRegards </s>