Overview

Blisters form when your skin is injured. They tend to show up on your hands and feet. Friction from tools or shoes causes them. Blisters are your body’s natural way of protecting itself from further damage. A bubble of fluid collects to cushion the wound and give the skin underneath time to heal.

The bubble or dome of your blister acts like a bandage. It prevents most bacteria from entering the wound. If the skin covering the dome of your blister breaks, you’re at risk of developing an infection.

Infected blisters are often painful. They can also be dangerous if left untreated. A bacterial, viral, or fungal infection that starts in your blister can spread to other areas. It can even result in sepsis. This is a life-threatening infection of the bloodstream.

What are the symptoms?

It’s sometimes hard to distinguish an infected blister from an uninfected one. Most blisters are tender and painful, some more than others. However, there are a few reliable signs you can look for. Before examining your blister, wash your hands with warm water and soap to avoid introducing any bacteria.

With clean hands, feel the area around the blister for signs of:

  • warmth
  • foul smell
  • pus
  • pain
  • swelling
  • holes or peeling skin

You may also have an infected blister if the area bleeds when you touch it or doesn’t seem to be healing at all.

How is it treated?

If you suspect that your blister is infected, consult your doctor as soon as possible. There are many different things that can cause infections, so your doctor may perform a skin biopsy. In this procedure, your doctor takes a small tissue sample and analyzes it to determine its underlying cause.

Once your doctor has a better idea of what’s causing the infection, they might prescribe:

  • oral or topical antibiotics
  • oral or topical antifungal medications

They might also perform a quick in-office procedure to drain the blister. It’s very important that you leave this process to your doctor. Doing it on your own can make the infection worse or cause it to spread to nearby areas.

While you wait to see your doctor, there are a few things you can do at home to relieve your symptoms and fight the infection:

  • Clean the wound. Run the area under warm water and gently massage it with soap. Continue rinsing and washing for three to five minutes. Repeat at least twice a day.
  • Soak the wound. Soak your wound in a homemade saline solution. You can make this by adding 1 teaspoon of salt to 1 cup of warm water.
  • Treat the wound. After washing both your hands and the wound, apply a topical antibiotic ointment, such as Neosporin or Bacitracin.
  • Treat the pain. Take a nonsteroidal anti-inflammatory, such as ibuprofen (Advil), to help reduce pain and swelling.

Are there any complications?

Left untreated, serious infections can begin to spread to other areas of your body. In addition, bacteria can enter the blistered skin and result in a condition called cellulitis. This is a rapidly spreading skin infection. It can quickly become a medical emergency if it spreads to your lymph nodes or bloodstream.

Infected blisters can also lead to sepsis in severe cases. This happens when certain chemicals released by your immune system trigger a chain reaction in your body. Eventually, this can lead to septic shock. Septic shock is fatal about half the time. However, most people recover from milder cases of sepsis.

When to call a doctor

It’s best to see your doctor about any infected blister in order to avoid complications, which can be very serious.

I you notice a red streak moving up your leg, go to the emergency room immediately. This is a sign of cellulitis. It requires immediate treatment to prevent it from spreading too far.

You should also see your doctor right away or go to urgent care if you have:

  • a fever
  • chills
  • body aches
  • a blister or sore that’s not showing any signs of healing

The bottom line

Blisters aren’t usually anything to worry about. Most heal on their own within one or two weeks. While most blisters never become infected, it can be a serious health concern when they do.

If you participate in a lot of activities that lead to friction blisters, consider keeping some antibiotic ointment on hand to reduce your risk of infection. Make sure to check in with your doctor at the first sign of an infection to avoid complications.