Blisters appear! What is the difference between burns and friction blisters?

Audit expert: Zhang Yuhong

Zhengzhou Central Hospital Affiliated to Zhengzhou University

Chief Physician of Dermatology

A few days ago, when I went hiking, I unfortunately got blisters on my feet because my shoes didn't fit. After returning home, I felt uncomfortable and curious - what exactly are these blisters? Why do humans get blisters?

Blisters on the feet caused by friction Source: Wikipedia

The "blister" we usually refer to is a small bag of fluid accumulated in the surface of the skin. The scientific name of "blister" is vesicle, which can be divided into two types: blisters caused by skin trauma and blisters caused by viruses.

When blisters appear on the skin, we may feel that some blisters "do not feel anything", or we may feel pain or itching, or even have a fever. Today we will learn about the "blisters" on the body.

What exactly is a “blister”?

In medicine, "blister" can be understood as a symptom of skin damage . In fact, it is a herpes that rises from the surface of the skin, that is, blisters that grow on normal-looking skin. Blisters are often accompanied by epidermal peeling, and blisters induced by viruses are prone to occur in skin folds.

Source: Wikipedia

There are many causes of blisters. Common causes of blisters caused by skin trauma include abrasions, burns, sunburns, and allergic reactions. As the name suggests, viral blisters are caused by viruses. For example, the chickenpox virus can cause blisters on a person's skin.

How are blisters formed?

The mechanism of blister formation is very complex. Here we take burn blisters and friction blisters as examples.

1. Scald blisters: In the early stage after a scald, the capillaries in and around the scald area expand and their permeability increases. In layman's terms, the blood vessels become like "filters". A large amount of blood components pass through the "filters" and flow from the blood into the space between the skin and flesh. These liquids flow under the skin, lift up the thin epidermis, form edema, or ooze out from the site of injury. This is a scald blister.

Blisters caused by burns Source: Wikipedia

2. Friction blisters: When the skin is subjected to strong friction, thinner skin will break and fall off, while thicker skin will be torn away from the flesh and blood under the skin. When the subcutaneous tissue is stimulated, tissue fluid will flow out. If the skin is thin and falls off, the tissue fluid will flow out; when the skin is thick, the tissue fluid will fill the gap after the skin and flesh are torn apart, thus forming blisters. This is a friction blister.

Source: Wikipedia

What is the “water” inside the blisters?

The fluid in the blisters is composed of tissue fluid and partial components of blood , and its composition is very complex.

According to research from Liaoning University of Traditional Chinese Medicine and Nantong Medical College, blister bodies contain a large number of proteins, such as fibronectin, fibrinogen, galectin-10, haptoglobin, protease inhibitors, α2-HS glycoprotein, clusterin, etc., some of which have positive significance for wound healing.

For example, fibrinogen has the function of promoting blood coagulation, wound repair and anti-infection; galectin-10 has the function of regulating immunity and inflammatory response; haptoglobin has the function of anti-infection and stabilizing the internal environment; clusterin has the function of regulating cell growth and apoptosis.

What should I do if blisters appear?

Finally, we come to the topic that most concerns us all - what to do when blisters appear? The editor consulted the information of experts and gave you the following suggestions:

(I) For viral blisters and blisters caused by allergies: If the main feeling is itching, it may be a viral blisters or an allergic reaction. Try not to scratch it at this time, and see a doctor as soon as possible. The doctor will prescribe a suitable ointment for you to apply.

Blisters caused by chickenpox Source: Wikipedia

(ii) For other skin injury blisters: If you have non-allergic skin injury blisters, you can consider treating them yourself. If the blisters are not painful, try to keep them intact. The unbroken skin on the blisters can provide a natural bacterial barrier for the human body and reduce the risk of infection. If the injury is serious, you must go to the hospital for treatment immediately. The hospital will use antibiotics and tetanus drugs. If the blisters appear to be infected, you must also seek medical treatment. If you have diabetes or poor blood circulation, please contact a doctor before treating the blisters yourself.

However, for mild blisters, if the pain is unbearable, in order to relieve the discomfort, you can choose to drain the fluid in the blister, but at the same time keep the overlying skin intact, otherwise bacteria will quickly invade and infection will occur. So, how to drain the fluid?

1. Clean your hands and blisters with soap and warm water.
2. Wipe the surface of the blister with iodine.
3. Sterilize sharp needles with alcohol.
4. Use the needle to puncture the blister at several points near the edge of the blister to allow the fluid to drain, but leave the overlying skin in place.
5. Apply ointment to the blisters and cover with nonstick gauze. If a rash develops, stop using the ointment.
6. Check the blisters daily for infection. After a few days, cut away any dead skin with tweezers and scissors sterilized with alcohol. Apply ointment and dressings. That’s all about blisters. I would like to remind you and myself that no matter how well you deal with the blisters, it will only make you feel uncomfortable. It is better to stay away from hot things, exercise moderately, and wear appropriate shoes!