There are several causes of blisters.
'Blisters are usually caused by injury to the skin from heat or from friction, which create a tear between the epidermis—the upper layer of the skin—and the layers beneath.
Short periods of intense rubbing can cause a blister, but any rubbing of the skin at all can cause a blister if it is continued for long enough. Blisters form more easily on moist skin than on dry or soaked skin, and are more common in warm conditions.
Sometimes, the skin can blister when it comes into contact with a cosmetic, detergent, solvent or other chemical; this is known as contact dermatitis. Blisters can also develop as a result of an allergic reaction to an insect bite or sting.
There are also a number of medical conditions that cause blisters. The most common are chickenpox, herpes, impetigo, and a form of eczema called dyshidrosis. '
To relieve blister-related pain, drain the fluid while leaving the overlying skin intact.
* Wash your hands and the blister with soap and warm water.
* Swab the blister with iodine or rubbing alcohol.
* Sterilize a clean, sharp needle by wiping it with rubbing alcohol.
* Use the needle to puncture the blister. Aim for several spots near the blister's edge. Let the fluid drain, but leave the overlying skin in place.
* Apply an antibiotic ointment to the blister and cover with a bandage or gauze pad.
* Cut away all the dead skin after several days, using tweezers and scissors sterilized with rubbing alcohol. Apply more ointment and a bandage.
It would be best to consult a doctor if it does not resolve on its own in a few days.
Let us know if you need any other information.