A blister is a fluid-filled bump on the skin.
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Blisters have many causes, such as:
- Friction or constant pressure
- Second-degree burns
- Skin irritation from:
- Certain cancers
Blistering diseases—such as epidermolysis bullosa,
porphyria, or pemphigus
- Autoimmune disorders
Things that may increase the risk of blisters are:
- Wearing ill-fitting shoes
- Repetitive work with hand tools
- Getting a sunburn or frostbite
- Severe skin swelling, especially of the legs
Symptoms of a blister are:
- A fluid-filled bump on the skin, which is often round
- Fluid that is usually clear, but may be bloody, cloudy, or contain pus
The doctor will ask about your symptoms and health history. A physical exam will be done. Blisters may be diagnosed on appearance.
A blister will often heal without treatment. Sometimes the underlying cause needs to be treated.
Treatment options are:
- Washing the area
- Applying over-the-counter medicine—to ease itching and discomfort
- Applying antibiotic ointment—to prevent or treat an infection
- Bandaging the area—to protect it
To lower the risk of a blister:
- Wear shoes that fit properly. Always wear socks with your shoes.
- Use gloves or protective padding when working with tools.
- Wear a hat, protective clothing, and sunscreen when out in the sun.
- Avoid skin contact with irritating chemicals or plants
Abiad M, Kurban M, Abbas O. Recurrent blisters with pain following thermal burn injury to left leg and foot. Int J Dermatol. 2019;58(12):1377-1378.
Blistering skin conditions. DermNet New Zealand website. Available at: https://www.dermnetnz.org/topics/blistering-skin-conditions. Accessed January 29, 2021.
Blisters. Better Health Channel website. Available at: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/blisters. Accessed January 29, 2021.
Blisters—causes. NHS Choices website. Available at: http://www.nhs.uk/Conditions/Blisters/Pages/Causes.aspx. Accessed January 29, 2021.
Blisters, calluses, and corns. Kids Health—Nemours Foundation website. Available at: http://kidshealth.org/en/kids/blisters.html. Accessed January 29, 2021.
Major burns. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/major-burns. Accessed on February 18, 2021.
Last reviewed September 2020 by
EBSCO Medical Review Board
Shawna Grubb, RN
Last Updated: 2/18/2021