Blisters

Overview

Definition

A blister is a fluid-filled bump on the skin.

Blisters
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Causes

Blisters have many causes, such as:

  • Friction or constant pressure
  • Second-degree burns
  • Infections
  • Skin irritation from:
    • Contact dermatitis, such as poison ivy, oak, or sumac
    • Insect bites
    • Allergic reactions
    • Reactions to certain medicines or chemicals
    • Scabies
  • Certain cancers
  • Blistering diseases—such as epidermolysis bullosa, porphyria, or pemphigus
  • Autoimmune disorders

Risk Factors

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

SymptomsandDiagnosis

Symptoms

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

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done. Blisters may be diagnosed on appearance.

Treatments

Treatment

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

Prevention

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

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

RESOURCES

American Academy of Dermatology https://www.aad.org 

National Institute of Arthritis and Musculoskeletal and Skin Diseases https://www.niams.nih.gov 

CANADIAN RESOURCES

Canadian Dermatology Association https://dermatology.ca 

Health Canada http://www.canada.ca 

References

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.