A blister, which is also called a vesicle by medical professionals, is a raised portion of skin that is filled with fluid. You are probably familiar with blisters from wearing uncomfortable shoes for too long. This common cause of blistering produces vesicles when friction between your skin and the shoe causes layers of skin to separate and fill with fluid.
If you know the cause of your blister, you can treat it by covering it with bandages to keep it protected and comfortable. Eventually the fluids will seep back in and the blister will disappear. You should not puncture a blister unless it is very painful, as the skin over the fluid protects you from infection. If you are not sure why you have blistering, you should see your doctor.
There are many temporary causes of blisters:
- Friction occurs when something rubs against your skin for a prolonged period of time. This happens most commonly on hands and feet.
- Contact dermatitis is a skin reaction to allergens, like poison ivy, latex, or adhesives, or irritants, like chemicals or pesticides. It can cause red and inflamed skin, and also blistering.
- Burns, if severe enough, can produce blistering. This includes burns from heat, chemicals, and sunburns.
- Allergic eczema is a skin condition that is caused or worsened by allergens and can produce blisters. Another type of eczema, dyshidrotic eczema, also causes blistering, but its cause is unknown. It tends to come and go.
Blistering can also be a symptom of certain infections:
- Impetigo is a bacterial infection of the skin that can occur in both children and adults, and sometimes shows up after a viral infection. Blisters are a symptom of impetigo.
- Chickenpox is an infection caused by a virus. It produces itchy spots, and often blisters on the skin.
- Shingles, or herpes zoster, is caused by the same virus that produces chickenpox. The virus reappears in some people later in life and produces a skin rash with blistering.
- Herpes and the resulting cold sores can cause skin blistering. This includes both herpes I and II (which produces genital herpes).
- Erysipelas is an infection caused by the Streptococcus group of bacteria, which produces skin blisters as a symptom.
More rarely, blisters are the result of a skin condition. For many of these rare conditions, the cause is unknown. A few skin conditions that cause blisters include:
- dermatitis herpetiformis
- epidermolysis bullosa
Most blisters require no treatment. If you leave them alone, they will go away, and the top skin layers prevent infection. If possible, you should refrain from puncturing or breaking them open. Blisters caused by friction, allergens, and burns are temporary reactions to stimuli.
The blisters caused by infections are also temporary, but they may require treatment. If you suspect you may be suffering from some type of infection, you should see your doctor for a diagnosis and treatment. In addition to medication for the infection, your doctor may be able to give you something to treat the symptoms, including blistering.
If your blisters are caused by a rare skin condition, there may be no cure. Even without a cure for a particular condition, such as pemphigus, your doctor can guide you through treatment options that reduce the symptoms, including blistering. This may include steroid creams to relieve skin rashes or antibiotics to relieve skin infections.
In the majority of instances, blisters are not part of a life-threatening condition. Most will go away without treatment, but may cause you pain and discomfort in the meantime. If you treat an infection that is causing blisters, your outlook is similarly good. For rare skin conditions, how well treatments work will depend on each individual situation.
For the most common of blisters—those caused by friction on the skin of your feet—you can practice basic preventive measures. Always wear comfortable, well-fitting shoes. If you will be walking for a long period of time, use thickly cushioned socks to reduce friction. As you walk, you may feel a blister beginning to form. Stop and protect this area of skin with a bandage to prevent further friction.