Blisters: Causes, Care and Prevention

Blisters are fluid-filled sacs in the outer layer of the skin, caused by rubbing, heat or skin disease. They are most common on the hands and feet. Small ones are also called vesicles, large ones bullae.

Causes

Friction — rubbing or pressure on one spot — is the usual cause: shoes that don't quite fit, or raking leaves without gloves so the handle rubs your hand. Others include:

• burns, sunburn and frostbite;
• eczema and allergic reactions;
• poison ivy, oak and sumac;
• autoimmune diseases such as pemphigus;
• epidermolysis bullosa, which makes the skin fragile;
• viral infections — varicella zoster (chickenpox and shingles) and herpes simplex (cold sores);
• skin infections such as impetigo.

Care

• Blisters usually heal on their own; the skin over them helps keep out infection.
• A bandage keeps a blister clean. Make sure nothing keeps rubbing it.
• Don't drain a blister as a rule, because of the risk of infection — but if it is large, painful, or about to pop on its own, you can drain the fluid.

When to contact a health care provider

• The blister looks infected: draining pus, or the skin around it red, swollen, warm or very painful.
• You have a fever.
• You have several blisters, especially with no clear cause.
• You have health problems such as poor circulation or diabetes.

Preventing friction blisters

• Wear shoes that fit.
• Always wear well-fitting socks with shoes; acrylic or nylon socks keep moisture away from the feet.
• Wear gloves or protective gear when using tools or sports equipment that rub.

Sources

• "Blisters," MedlinePlus, U.S. National Library of Medicine. https://medlineplus.gov/blisters.html
• Rewritten in hubnx's own words.