A blister is a pocket of fluid that forms between upper layers of the skin. The fluid contained inside the blister can be lymph, blood, or pus. Blisters are the normal reaction of the skin to outside stressors. The fluid pocket protects the skin underneath from further injury.
Blisters are very common. Blisters can be itchy or may hurt a little. Blisters hurt as the fluid presses on the nerves in the skin. Blisters can burst or, the top layer of the blister can be torn to expose the more delicate skin layers underneath. These ‘opened’ blisters are generally painful.
Blisters look like ‘bubbles’ on the skin. Depending on the cause, blisters can appear singly or in clusters. Blisters are considered wounds because rupture of skin integrity takes place. In medical terms, tiny blisters are called vesicles while large ones are termed as a bulla.
Many people sustain blisters when an area of the skin has been forcefully rubbed on a surface repeatedly for a long time. Activities such as playing musical instruments, running, using joysticks, or digging with a shovel can cause blisters to form in the hands or feet. However, blisters can have other causes.
Most blisters form when the top of the skin surface is subjected to shear stress, causing the top layer of the skin to break off. Fluid from cells now collects in the space between skin layers, forming a blister. Some blisters, called blood blisters, fill with blood caused by a break in tiny blood vessels near the skin. If a blister becomes infected, it may become filled with pus.
Blisters are often caused by friction to the skin. Sustaining burns or sunburn can also cause blisters to form. Exposure to extreme cold or heat can also cause blisters to form on the exposed skin.
Aggressive pinching or crushing the skin can also cause blisters, often blood blisters, to form. Infected blisters that remain intact may become filled with pus. Blisters can also occur from exposure to certain chemicals, toxins, or certain bug bites.
Some blisters are caused by certain health problems. Some medical conditions cause the formation of blister lesions as a symptom. Diseases like chicken pox, herpes, impetigo, and contact dermatitis may cause blisters to form.
Blisters are easy to identify. However, blisters or blister-like lesions that are possibly caused by health conditions should be assessed by a doctor. The cause of blister should be thoroughly investigated.
For small blisters not caused by medical conditions and were not burst open, the fluid is gradually reabsorbed and swelling subsides. Blisters that cause too much pain may need to be burst open. Bursting blisters should be done in a careful manner to prevent introducing bacteria in the wound that can result in infection.
Like most skin wounds, blisters often heal on their own without treatment. Healing occurs within 24 to 48 hours after the blister has formed. The same thing cannot be said to blisters that are caused by medical conditions. Blisters that occur as a symptom often heals only if the cause is addressed.
Many things can give you blisters. The most common cause of blister is repeated forceful friction on the skin. Our skin is actually composed of several layers, and these layers may separate from shear stress caused by forceful friction. The hands and the feet are often subjected to shear stress, and because these areas have thick skin layers, are often at risk of blisters.
Certain activities can make you prone to friction blisters, such as:
Running or jogging, especially when using poorly-fitted shoes
Using items such as joysticks, which may cause blisters on the fingers
Activities such as sports, home improvement, gardening, chopping wood or cooking food, which may cause blisters on the feet or hands.
Exposure to temperature extremes:
Bare skin exposed to too hot or too cold temperatures can cause it to form blisters. In this case, blister formation is a reaction to protect deeper skin layers from further injury. You can have clusters of tiny blisters on the hands if you went out without wearing gloves during winter. You can also have blisters when you burn yourself with hot water or after touching something that is very hot.
Another common cause of blisters is sunburn. Ionizing radiation can burn the skin and cause blisters to form. Excessive exposure to other sources of radiation, such as tanning beds or sunlamps, can give you blisters.
Crushing or pinching the skin:
Aggressive pinching of the skin may cause blisters to form. Sometimes, pinching may break tiny blood vessels and cause the formation of blood blisters.
Exposure to insect bites:
Some insect bites are not just painful, but also gives leaves blisters. Some biting insects that do this are bed bugs, ants, fire ants, scabies mites, blister beetles, and in some people, mosquitoes.
Contact dermatitis is a type of eczema that occurs when the skin touches something. Contact dermatitis may cause rashes and blisters. People may sometimes get contact dermatitis from latex gloves, soaps, perfume, detergents, makeups, jewelry, touching poison ivy, or nickel.
Touching corrosive substances:
Certain corrosive substances, such as battery acid, bleach, or pepper spray, can cause blisters on the skin. Blister agents, which can be used in chemical warfare, cause large incapacitating blisters.
Some medical conditions cause the formation of lesions that look like blisters. These conditions should be thoroughly investigated. In most cases, usual first aid treatments will not work for this kind of blisters. Here are those conditions that cause lesions that look like blisters:
Blisters are easily noticed and felt. Blisters caused by friction, extremes of temperature, pinching, or radiation heals on its own without treatment. In less than 24 hours after formation, new skin forms beneath the blister. The fluid is gradually absorbed, and the skin covering the blister dries and peels off.
Usually, blisters should not be drained. If the blister is so swollen that it causes pain, or becomes infected or irritated, it should be popped. You can pop blisters on your own. However, it should be done carefully to avoid introducing germs into the blister that can cause infection.
Here are the steps to pop a blister properly:
Have a very sharp razor blade or needle, and purchase sterilized ones if possible.
You can sterilize razor blades or needles by putting it in the flame until red hot, and then cooled, or rinsing them in alcohol.
Wash your hands thoroughly, and also wash the blister carefully
Using the sterilized blade or needle, make several tiny holes around the edge of the blister. Making several holes help drain the blister evenly.
Gently squeeze the blister to remove the fluid. Take care not to apply too much pressure to prevent deforming the skin over the blister.
Leave the skin intact, and do not remove it. This will act as a covering to help heal the blister.
Put antibiotic ointment or cream over the blister.
If the fluid that comes out the blister is green or yellow, it is infected and requires doctor’s attention.
If the skin covering the blister has been removed, the wound is open and there is a higher risk of infection. Hydrocolloid dressings may be applied to large and open blisters to reduce discomfort and promote healing.
You can apply a dressing or bandage over the blister to protect it from harm while it heals. Always change the dressing daily, and when visibly soiled or wet.
Blisters that are infected should be seen by the doctor. Blisters that have visible pus, surrounded by red or warm skin, or have red streaks leading away from the blister are infected. Only a doctor should pop infected blisters.
Blisters caused by frostbite, sunburn, radiation or contact dermatitis can be painful. You can reduce pain by applying a cold compress for no more than 15 minutes. Blisters caused by bug bites (like bed bugs) can cause intense itchiness, which can lead to scratching and worsen skin irritation. Try to avoid scratching, and apply weak corticosteroid cream to alleviate itching.
Blisters caused by medical conditions should be addressed differently. For example, touching cold sore blisters and chicken pox sores can pass germs to others and spread the condition. Usually, treating the causative health condition cause blisters to heal. Such blisters must never be popped open.
You can do simple measures to prevent having blisters. You can avoid blisters on the feet by wearing good socks. For tough situations, you can wear two layers of socks. Change wet socks right away as wet skin are more likely to sustain blisters.
Make sure to break in new shoes or hiking boots before wearing them. You can also put pads, bandages, or moleskin on blister-prone skin before hiking or running. To prevent blisters on hands, wear gloves fit for the activity. You can apply talcum powder along with gloves and tape to prevent hand blisters when grabbing heavy items.
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