Skin Problems: Blisters Causes and Treatment

Blisters are fluid filled circular pockets of skin.

What Are Blisters?

They're bubbles that pop up when fluid collects in pockets under the top layer of your skin. They can be filled with pus, blood, or the clear, watery part of your blood called serum. Most are shaped like circles. Depending on the cause, your blister could itch or hurt a lot or a little. They can appear as a single bubble or in clusters.

Friction blisters develop as a result of friction on your heel, toe, thumb, or palm.

Friction

Friction blisters, named for what causes them, are one of the most common kinds. Think back. Have you ever worn a new pair of hiking boots before you broke them in? Or raked the yard without a pair of garden gloves on your hands? Those are the kinds of things that could cause a friction blister on your heel, toe, thumb, or palm.

Heat and cold may result in blisters.

Cold and Heat

Go without gloves in winter and you could get blisters from frostbite. Stay out in the summer sun too long and you might get sunburn. The same thing can happen if you handle frozen goods or touch the stove burner. Both cold and heat are described as "blistering" for good reason: Extreme temperatures can hurt your skin. Blisters are a sign of a type of second-degree burn called partial thickness.

If you rub up against certain plants, like poison ivy, you may get contact dermatitis.

Contact Dermatitis

Rub up against a pesky plant like poison ivy, and you might end up with blisters of another sort. They're often a symptom of contact dermatitis, which happens when you touch something you're allergic to. It doesn't have to be poisonous, though. Some people react to soap, perfume, detergent, fabric, jewelry, latex gloves, or things used to make tools, toys, or other everyday objects.

Sometimes, very itchy blisters appear on your palms or the soles of your feet as a result of atopic dermatitis or eczema.

Atopic Dermatitis

Also known as eczema, this condition usually shows up as a rash. But with some types, you can also get blisters filled with clear fluid. Dyshidrotic eczema causes these super-itchy blisters on your palms and the soles of your feet. Blisters filled with pus are a sign your eczema has become infected. If you think you may have a skin infection, see your doctor.

Itchy bug bites may develop into blisters.

Bug Bites

Insects can take the blame for some itchy blisters. Scabies are tiny mites that drill into your skin, sometimes leaving curved lines of blisters in their tracks. They often attack the hands, feet, wrists, and under the arms. Flea and bedbug bites can cause little blisters, too. The brown recluse spider has an extra-nasty bite that blisters before bursting to form a painful open sore. If that describes your blister, go to the doctor right away.

Herpes viruses like chickenpox and shingles may give you painful rashes with blisters.

Chickenpox & Shingles

Some viruses can cause blisters. The herpes virus is a common culprit. It's present in chickenpox, a contagious illness that starts with red bumps that become blisters and then scab over. If you've had chickenpox, you also can get shingles, which targets nerves and causes a painful rash with blisters. The CDC says people 60 and older should get a one-time vaccination to prevent shingles. It also recommends two doses of chickenpox vaccine for anyone who hasn't had the disease.

Blisters on the lips, mouth, or genitals may be due to the herpes simplex virus.

Herpes Simplex

Fever blisters on your lips, mouth, or genitals are a sign of the herpes simplex virus. The fluid in these sores carries and spreads the virus through sex, or by kissing or sharing utensils. Many people don't know they have herpes because symptoms are usually mild. If you have fever blisters or you think you've been exposed to herpes, talk to your doctor. There's no cure, but certain drugs can prevent or shorten outbreaks.

Hand-foot-and-mouth disease results in blisters on the hands, feet, and mouth.

Hand-Foot-and-Mouth Disease

This disease is named after the blisters it causes on these body parts. The infection mostly hits kids younger than 10. The virus spreads through contact with mucus, saliva, feces, or blisters of someone who's already sick. The infection starts out with a mild fever, runny nose, and sore throat. But the blisters are the big clue that leads to a diagnosis.

Most blisters will heal on their own and you can cover them with special bandages to protect them.

Keep It Clean and Dry

Some blisters get better on their own. Your skin absorbs the fluid, and the blister flattens and peels off. Until that happens, you can use a donut-shaped piece of moleskin padding or tape to help keep it from breaking open.

Do not pop a blister unless it's very large or painful and if it is, let a doctor drain the fluid.

Don’t Pop if You Don’t Have To

Resist the urge to pop a blister unless it's so large -- bigger than a nickel -- or painful that you can't get around. If that's the case, your doctor might decide to puncture it with a sterile needle to let the fluid drain out. Once it's popped, whether your doctor does it or it breaks on its own, gently wash the area with soap and water and apply antibiotic ointment. Cover it with a bandage to keep it clean during the day, but take the bandage off at night to let it dry.

See your doctor if you have flu-like symptoms or pain, redness or swelling around a blister.

When to See Your Doctor

Go to the doctor if you have a fever, chills, or other flu-like symptoms at the same time you have blisters. You could have a virus or an infection. Other symptoms of infection can include: pain, swelling, redness or warmth, red streaks leading away from your blister, or pus coming from it. Blisters around your eyes or on your genitals are also cause for concern.

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REFERENCES:

  • Johns Hopkins Medicine: "Glossary -- Pediatrics," "Health Library: Blisters," "Health Library: Chickenpox (Varicella)."
  • American Academy of Pediatrics. "Healthy Children: Blisters."
  • University of New Mexico Hospitals: "Burn Classification."
  • Johns Hopkins Medicine: "Health Library: Poison Ivy," "Health Library: Contact Dermatitis."
  • Nemours: "Infections: Scabies."
  • Virtua Hospital System: "Kids Health: A to Z: Insect Bites/Stings, Non-Venomous."
  • CDC, Workplace Safety & Health Topics: "Venomous Spiders."
  • American Academy of Dermatology: "Shingles: Signs and symptoms," "Herpes simplex: Signs and symptoms," "Herpes simplex: Who gets and causes," "Shingles: Diagnosis, treatment, and outcome."
  • American Academy of Family Physicians: "Herpes: Treatment"
  • CDC: "Vaccines and Immunizations: Shingles Vaccination: What You Need to Know," "Vaccines and Immunizations: Chickenpox Vaccination: What Everyone Should Know," "Genital Herpes Treatment."
  • New York State Department of Health: "Hand, Foot and Mouth Disease (Coxsackie viral infection)."
  • Seattle Children's: "Should Your Child See a Doctor: Blisters."
  • NYU Langone Medical Center Department of Pediatrics: "Blisters."
  • National Eczema Association: "Dyshidrotic Eczema."
  • National Eczema Society: "About skin infections and eczema."
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