A blister or bulla is a defense mechanism of the human body. It consists of a pool of lymph and other bodily fluids beneath the upper layers of the skin. It may be formed in response to burns or friction, and helps to repair damage to the skin. If a blister is punctured, it forms an open wound and must be bandaged.

If a blister is associated with sub-dermal bleeding, it may partially fill with blood, forming an unpleasant blood blister.

Blistering is a distinguishing characteristic of second degree burns.

Certain autoimmune diseases feature extensive blistering. These include pemphigus and pemphigoid . Blistering also occurs as part of foodborne illness with Vibrio vulnificus (seafood).

The class of chemical weapons known as vesicants acts by causing blisters (often within in the respiratory tract). Mustard gas and lewisite are examples of such agents.

See also

• Buboe
• Dracunculiasis
• Herpangina
• Herpes zoster
• Ulcer

External links

• How to Care for a Blister