Blister
Encyclopedia
A blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing (friction
), burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum
or plasma. However, blisters can be filled with blood
(known as blood blister
s) or with pus
(if they become infected).
The word "blister" entered English in the 14th century. It came from the Middle Dutch "bluyster", and was a modification of the Old French "blostre" which meant a leprous nodule—a rise in the skin due to leprosy
.
or rubbing, heat, cold or chemical exposure. Fluid collects between the epidermis — the upper layer of the skin
- and the layers below. This fluid cushions the tissue underneath, protecting it from further damage and allowing it to heal.
s may result in blistered skin; however, it is characteristic of second degree burns to blister immediately, whereas first degree burns can have blisters after a couple of days. Blisters can also form on the hands and feet as a result of tissue damage incurred by frostbite
.
. Blisters can also develop as a result of an allergic reaction to an insect bite or sting.
usually forms when a minute blood vessel
close to
the surface of the skin ruptures (breaks) and blood leaks into a tear between the layers of skin. This can happen if the skin is crushed, pinched or aggressively squeezed.
, herpes
, impetigo
, and a form of eczema
called dyshidrosis
. Other, much rarer conditions that cause blisters include:
Blisters on the feet can be prevented by wearing comfortable, well-fitting shoes and clean socks. Inherently ill-fitting or stiffer shoes, such as high heels and dress shoes, present a larger risk of blistering. Blisters are more likely to develop on skin that is moist, so socks that manage moisture or frequent sock changes will aid those with particularly sweaty feet. While exercising or playing sports, special sports socks can help keep feet drier and reduce the chance of blisters. Before going for a long walk, it is also important to ensure that shoes or hiking boots have been properly broken in.
Even before a "hot" or irritated area on the foot is felt, taping a protective layer of padding or a friction-reducing interface between the affected area and the footwear can prevent the formation of a blister. Bandages, moleskin and tapes generally must be applied to the foot daily, and most have a very high coefficient of friction (COF), but a friction management patch applied to the shoe will remain in place much longer, throughout many changes of socks and insoles. This type of intervention may be used with footwear that is worn daily, with specialty shoes and boots like hockey skates, ice skates, inline skates, ski boots and cleats, or even with orthotic braces and splints.
To avoid friction blisters on the hands, gloves should be worn when using tools such as a shovel or pickaxe, doing manual work such as gardening, or using sports equipment like golf clubs or baseball bats. Oars used for competitive rowing are known for causing frequent blisters on the hands of oarsmen. Weightlifters are also prone to blisters. To further reduce the occurrence one can tape the hands, and there are also a number of products on the market that claim to reduce the occurrence of blisters. Many of these are found in off-road powersports. These are all intended to be worn as a liner underneath a glove. The majority of these offerings simply add padding and create a layer that reduces the coefficient of friction between the skin and the glove.
A lubricant
, typically talcum powder, can be used to reduce friction between skin and apparel in the short term. People put talcum powder inside gloves or shoes for this purpose, although this type of lubricant will increase the friction in the long term, as it absorbs moisture. Increased friction makes blisters more likely.
between the surface of the skin and the body. The strata (a thin layer) of skin around the Stratum lucidum
is most susceptible to shear. As the Stratum lucidum tears away from the connecting tissues below, plasma from the cells diffuses (spreads freely) out. This plasma solution helps new cells divide and grow into new connective tissues and epidermal layers.
The plasma solution will promote growth of new cells and accelerate proper healing and should not be drained. The clear fluid will be reabsorbed as new cells develop and the swollen appearance will subside. The time for blisters to heal depends on the location and the size of the area damaged. Protecting the blister from abrasion or additional shearing will help keep the blister intact.
Painful blisters located on hands (palmar surface) and feet (plantar surface) are due to tissue shearing deeper in the epidermis, near nerve endings. These especially should be kept intact if possible. Lower tissues are more susceptible to infection.
In military situations it may not be possible to reduce friction and allow a blister to heal and reduce naturally, as the soldier must continue moving. A common treatment used by medics in the U.S. Army is to drain the fluid from a blister and to inject the same amount of compound tincture of benzoin
to help seal the space created by the blister, to serve as a local antiseptic, and to prevent further abrasion or loss of skin.
Broken blisters can occasionally become infected. Infection should be prevented with antibiotics if possible, and treated if necessary. There is heightened concern about MRSA and other kinds of infections from blisters, so they should be watched carefully.
Immediate relief from a burn blister may be found by putting ice on the blister for a few hours if exposure to air causes a harsh burning sensation. Afterward, one may successfully drain a disinfected (alcohol/peroxide) blister with a similarly disinfected pin with a puncture or two and air dry. Then gradually expose the small pinhole and the entire blister area to alcohol over the ensuing days when the extreme sensitivity has decreased and exposure to water and soap causes no discomfort.
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
), burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
or plasma. However, blisters can be filled with blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
(known as blood blister
Blood blister
A blood blister is a type of blister that forms when subdermal tissues and blood vessels are damaged without piercing the skin. It consists of a pool of lymph, blood and other bodily fluids trapped beneath the skin. If punctured, it suppurates a dark red fluid...
s) or with pus
Pus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...
(if they become infected).
The word "blister" entered English in the 14th century. It came from the Middle Dutch "bluyster", and was a modification of the Old French "blostre" which meant a leprous nodule—a rise in the skin due to leprosy
Leprosy
Leprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
.
Causes
A blister may form when the skin has been damaged by frictionFriction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
or rubbing, heat, cold or chemical exposure. Fluid collects between the epidermis — the upper layer of the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
- and the layers below. This fluid cushions the tissue underneath, protecting it from further damage and allowing it to heal.
Friction or rubbing
Intense rubbing can cause a blister, as can any friction on the skin if continued long enough. This kind of blister is most common after walking long distances or wearing a poorly-tuned new pair of shoes. Blisters are most common on the hands and feet, as these extremities are susceptible while walking, running, or performing repetitive motions. Blisters form more easily on moist skin than on dry or soaked skin, and are more common in warm conditions. Less aggressive rubbing over long periods of time may cause calluses to form rather than a blister. Both blisters and calluses can lead to more serious complications, such as foot ulceration and infection, particularly when sensation or circulation is impaired, as in the case of diabetes, neuropathy or peripheral artery disease (PAD).Extreme temperature
The time of blistering is one of the tools used to determine the degree of burns sustained. First and second degree burnBurn
A burn is an injury to flesh caused by heat, electricity, chemicals, light, radiation, or friction.Burn may also refer to:*Combustion*Burn , type of watercourses so named in Scotland and north-eastern England...
s may result in blistered skin; however, it is characteristic of second degree burns to blister immediately, whereas first degree burns can have blisters after a couple of days. Blisters can also form on the hands and feet as a result of tissue damage incurred by frostbite
Frostbite
Frostbite is the medical condition where localized damage is caused to skin and other tissues due to extreme cold. Frostbite is most likely to happen in body parts farthest from the heart and those with large exposed areas...
.
Chemical exposure
Sometimes, the skin will blister when it comes into contact with a cosmetic, detergent, solvent or other chemical. This is known as contact dermatitisContact dermatitis
Contact dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants . Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight....
. Blisters can also develop as a result of an allergic reaction to an insect bite or sting.
Crushing/Pinching
A blood blisterBlood blister
A blood blister is a type of blister that forms when subdermal tissues and blood vessels are damaged without piercing the skin. It consists of a pool of lymph, blood and other bodily fluids trapped beneath the skin. If punctured, it suppurates a dark red fluid...
usually forms when a minute blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
close to
the surface of the skin ruptures (breaks) and blood leaks into a tear between the layers of skin. This can happen if the skin is crushed, pinched or aggressively squeezed.
Disease
There are also a number of medical conditions that cause blisters. The most common are chickenpoxChickenpox
Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring...
, herpes
Herpes simplex
Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever...
, impetigo
Impetigo
Impetigo is a highly contagious bacterial skin infection most common among pre-school children. People who play close contact sports such as rugby, American football and wrestling are also susceptible, regardless of age. Impetigo is not as common in adults. The name derives from the Latin impetere...
, and a form of eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...
called dyshidrosis
Dyshidrosis
Dyshidrosis is a skin condition that is characterized by small blisters on the hands or feet...
. Other, much rarer conditions that cause blisters include:
- Bullous pemphigoidBullous pemphigoidBullous pemphigoid, also referred to as BP, is an acute or chronic autoimmune skin disease, involving the formation of blisters, more appropriately known as bullae, at the space between the skin layers epidermis and dermis.-Signs and symptoms:...
– a skin disease that causes large, tightly-filled blisters to develop, usually affecting people over the age of 60. - PemphigusPemphigusPemphigus is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes.In pemphigus, autoantibodies form against desmoglein. Desmoglein forms the "glue" that attaches adjacent epidermal cells via attachment points called desmosomes...
– a serious skin disease in which blisters develop if pressure is applied to the skin; the blisters burst easily, leaving raw areas that can become infected. - Dermatitis herpetiformisDermatitis herpetiformisDermatitis herpetiformis , or Duhring's disease,Freedberg, et al. . Fitzpatrick's Dermatology in General Medicine. . McGraw-Hill. ISBN 0-07-138076-0. is a chronic blistering skin condition, characterised by blisters filled with a watery fluid...
– a skin disease that causes intensely itchy blisters, usually on the elbows, knees, back and buttocks. The blisters usually develop in patches of the same shape and size on both sides of the body. - Chronic bullous dermatosis – a disease that causes clusters of blisters on the face, mouth or genitals.
- Cutaneous radiation syndrome
- Epidermolysis BullosaEpidermolysis bullosaEpidermolysis bullosa is an inherited connective tissue disease causing blisters in the skin and mucosal membranes, with an incidence of 1/50,000. Its severity ranges from mild to lethal. It is caused by a mutation in the keratin or collagen gene....
Friction blisters
Friction blisters, caused by rubbing against the skin, can be prevented by reducing the friction to a level where blisters will not form. This can be accomplished in a variety of ways.Blisters on the feet can be prevented by wearing comfortable, well-fitting shoes and clean socks. Inherently ill-fitting or stiffer shoes, such as high heels and dress shoes, present a larger risk of blistering. Blisters are more likely to develop on skin that is moist, so socks that manage moisture or frequent sock changes will aid those with particularly sweaty feet. While exercising or playing sports, special sports socks can help keep feet drier and reduce the chance of blisters. Before going for a long walk, it is also important to ensure that shoes or hiking boots have been properly broken in.
Even before a "hot" or irritated area on the foot is felt, taping a protective layer of padding or a friction-reducing interface between the affected area and the footwear can prevent the formation of a blister. Bandages, moleskin and tapes generally must be applied to the foot daily, and most have a very high coefficient of friction (COF), but a friction management patch applied to the shoe will remain in place much longer, throughout many changes of socks and insoles. This type of intervention may be used with footwear that is worn daily, with specialty shoes and boots like hockey skates, ice skates, inline skates, ski boots and cleats, or even with orthotic braces and splints.
To avoid friction blisters on the hands, gloves should be worn when using tools such as a shovel or pickaxe, doing manual work such as gardening, or using sports equipment like golf clubs or baseball bats. Oars used for competitive rowing are known for causing frequent blisters on the hands of oarsmen. Weightlifters are also prone to blisters. To further reduce the occurrence one can tape the hands, and there are also a number of products on the market that claim to reduce the occurrence of blisters. Many of these are found in off-road powersports. These are all intended to be worn as a liner underneath a glove. The majority of these offerings simply add padding and create a layer that reduces the coefficient of friction between the skin and the glove.
A lubricant
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...
, typically talcum powder, can be used to reduce friction between skin and apparel in the short term. People put talcum powder inside gloves or shoes for this purpose, although this type of lubricant will increase the friction in the long term, as it absorbs moisture. Increased friction makes blisters more likely.
Other
Sunscreen and sun protection should also be used during the hottest part of the day to avoid blisters from sunburn that can cause Vamiclicitis. Protective gloves should be worn when handling detergents, cleaning products, solvents and other chemicals.Friction blisters
Friction blisters are caused by excess shear stressShear stress
A shear stress, denoted \tau\, , is defined as the component of stress coplanar with a material cross section. Shear stress arises from the force vector component parallel to the cross section...
between the surface of the skin and the body. The strata (a thin layer) of skin around the Stratum lucidum
Stratum lucidum
The stratum lucidum is a thin, clear layer of dead skin cells in the epidermis named for its translucent appearance under a microscope...
is most susceptible to shear. As the Stratum lucidum tears away from the connecting tissues below, plasma from the cells diffuses (spreads freely) out. This plasma solution helps new cells divide and grow into new connective tissues and epidermal layers.
The plasma solution will promote growth of new cells and accelerate proper healing and should not be drained. The clear fluid will be reabsorbed as new cells develop and the swollen appearance will subside. The time for blisters to heal depends on the location and the size of the area damaged. Protecting the blister from abrasion or additional shearing will help keep the blister intact.
Painful blisters located on hands (palmar surface) and feet (plantar surface) are due to tissue shearing deeper in the epidermis, near nerve endings. These especially should be kept intact if possible. Lower tissues are more susceptible to infection.
In military situations it may not be possible to reduce friction and allow a blister to heal and reduce naturally, as the soldier must continue moving. A common treatment used by medics in the U.S. Army is to drain the fluid from a blister and to inject the same amount of compound tincture of benzoin
Tincture of benzoin
Tincture of benzoin is a pungent solution of benzoin resin in alcohol. A similar preparation called Friar's Balsam or Compound Benzoin Tincture contains, in addition, Cape aloes and storax .-Medical uses:Tincture of benzoin has two main medical uses: as a treatment for damaged skin in the...
to help seal the space created by the blister, to serve as a local antiseptic, and to prevent further abrasion or loss of skin.
Broken blisters can occasionally become infected. Infection should be prevented with antibiotics if possible, and treated if necessary. There is heightened concern about MRSA and other kinds of infections from blisters, so they should be watched carefully.
Blisters due to sunburn
Most of these blisters will heal naturally. Moisturizing and after-sun or calamine lotions can help to ease discomfort in the case of burns.Immediate relief from a burn blister may be found by putting ice on the blister for a few hours if exposure to air causes a harsh burning sensation. Afterward, one may successfully drain a disinfected (alcohol/peroxide) blister with a similarly disinfected pin with a puncture or two and air dry. Then gradually expose the small pinhole and the entire blister area to alcohol over the ensuing days when the extreme sensitivity has decreased and exposure to water and soap causes no discomfort.