A blister is a small pocket of body fluid ‘lymph, serum, plasma, blood, or pus’ within the upper layers of the skin, typically caused by forceful rubbing, burning, freezing, chemical exposure or infection.
Most blisters are filled with a clear fluid, either serum or plasma. However, blisters can be filled with blood known as “blood blisters” or with pus if they become infected ..
Most blisters caused by friction or minor burns do not require a doctor’s care. New skin will form underneath the affected area and the fluid is simply absorbed. … The fluid-filled blister keeps the underlying skin clean, which prevents infection and promotes healing ..
If the burned skin or blisters have broken open, a bandage is needed. To further help prevent infection, apply a clean bandage whenever your bandage gets wet or soiled. If a bandage is stuck to a burn, soak it in warm water to make the bandage easier to remove.