Wart
Encyclopedia
Blister
A blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing , burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum or plasma...
. They are caused by a viral infection, specifically by human papillomavirus
Human papillomavirus
Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes...
2 and 7. There are as many as 10 varieties of warts, the most common considered to be mostly harmless. It is possible to get warts from others; they are contagious and usually enter the body in an area of broken skin. They typically disappear after a few months but can last for years and can recur.
Types
A range of types of wart have been identified, varying in shape and site affected, as well as the type of human papillomavirus involved. These include:- Common wart (Verruca vulgaris), a raised wart with roughened surface, most common on hands, but can grow anywhere on the body;
- Flat wartVerruca planaVerruca plana, also known as a "flat wart", is a reddish-brown or flesh-colored, slightly raised, flat-surfaced, well-demarcated papule of 2 to 5 mm in diameter. Upon close inspection, these lesions have a surface that is "finely verrucous". Most often, these lesions affect the hands or...
(Verruca plana), a small, smooth flattened wart, flesh-coloured, which can occur in large numbers; most common on the face, neck, hands, wrists and knees; - Filiform or digitate wart, a thread- or finger-like wart, most common on the face, especially near the eyelids and lips;
- Genital wartGenital wartGenital warts is a highly contagious sexually transmitted disease caused by some sub-types of human papillomavirus . It is spread through direct skin-to-skin contact during oral, genital, or anal sex with an infected partner...
(venereal wart, Condyloma acuminatum, Verruca acuminata), a wart that occurs on the genitalia. - Mosaic wart, a group of tightly clustered plantar-type warts, commonly on the hands or soles of the feet;
- Periungual wartPeriungual wartPeriungual warts are warts that cluster around the fingernail or toenail. They appear as thickened, fissured cauliflower-like skin around the nail plate. Periungual warts often cause loss of the cuticle and paronychia...
, a cauliflower-like cluster of warts that occurs around the nails. - Plantar wartPlantar wart-External links:* at the Mayo Clinic website* at The Merck Manual* at dermnet.com...
(verruca, Verruca plantaris), a hard sometimes painful lump, often with multiple black specks in the center; usually only found on pressure points on the soles of the feet;
Cause
Warts are caused by the human papilloma virus (HPV). There are about 130 known types of human papilloma viruses. HPV infects the squamous epitheliumSquamous epithelium
In anatomy, squamous epithelium is an epithelium characterised by its most superficial layer consisting of flat, scale-like cells called squamous epithelial cells...
, usually of the skin or genitals, but each HPV type is typically only able to infect only a few specific areas on the body. Many HPV types can produce a benign growth, often called a "wart" or "papilloma", in the area they infect. Many of the more common HPV and wart types are as follows:
- Common warts - HPV types 2 and 4 (most common); also types 1, 3, 26, 29, and 57 and others.
- Cancers and Genital dysplasiaDysplasiaDysplasia , is a term used in pathology to refer to an abnormality of development. This generally consists of an expansion of immature cells, with a corresponding decrease in the number and location of mature cells. Dysplasia is often indicative of an early neoplastic process...
- "high-risk" HPV types are associated with cancers, (cervical cancerCervical cancerCervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
and can also cause some vulvarVulvar cancerVulvar cancer, a malignant invasive growth in the vulva, accounts for about 4 % of all gynecological cancers and typically affects women in later life. It is estimated that in the United States in 2006 about 3,740 new cases will be diagnosed and about 880 women will die as a result of vulvar cancer...
, vaginalVaginal cancerVaginal cancer is any type of cancer that forms in the tissues of the vagina. Primary vaginal cancer is rare in the general population of women and is usually a squamous carcinoma. Metastases are more common. Vaginal cancer occurs more often in women over age 50, but can occur at any age, even in...
, penile, analAnal cancerAnal cancer is a type of cancer which arises from the anus, the distal orifice of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer. The etiology, risk factors, clinical progression, staging, and treatment are all different. Anal cancer is typically a...
and some oropharyngeal cancersHPV-positive oropharyngeal cancerHuman papillomavirus -positive oropharyngeal cancer also known as HPV16+ oropharyngeal cancer or HPV+ OPC is a recognized subtype of Oropharyngeal squamous cell carcinomas , associated with the HPV type 16 virus.-Causes:...
. "low-risk" types are associated with warts or other conditions.) - High-risk: 16, 18 (cause the most cervical cancer); also 58, 33, 45, 31, 52, 35, 39, 59, and others.
- Plantar wartPlantar wart-External links:* at the Mayo Clinic website* at The Merck Manual* at dermnet.com...
s (myrmecia) - HPV type 1 (most common); also types 2, 3, 4, 27, 28, and 58 and others. - Anogenital warts (condylomata acuminata or venereal warts) - HPV types 6 and 11 (most common); also types 42, 44 and others.
- Low-risk: 6, 11 (most common); also 13, 44, 40, 43, 42, 54, 61, 72, 81, 89, and others.
- Flat wartVerruca planaVerruca plana, also known as a "flat wart", is a reddish-brown or flesh-colored, slightly raised, flat-surfaced, well-demarcated papule of 2 to 5 mm in diameter. Upon close inspection, these lesions have a surface that is "finely verrucous". Most often, these lesions affect the hands or...
s - HPV types 3, 10, and 28. - Butcher's wartButcher's wartButcher's wart is a cutaneous condition caused by a small group of viruses that infect the skin.An association with human papillomavirus 7 has been suggested....
s - HPV type 7. - Heck's diseaseHeck's diseaseHeck's disease is a cutaneous condition characterized by white to pinkish papules that occur diffusely in the oral cavity. It is caused by the human papilloma virus types 13 and 32.- References :...
(Focal epithelial hyperplasia) - HPV types 13 and 32.
Pathophysiology
Common warts have a characteristic appearance under the microscopic. They have thickening of the stratum corneumStratum corneum
The stratum corneum is the outermost layer of the epidermis, consisting of dead cells that lack nuclei and organelles. The purpose of the stratum corneum is to form a barrier to protect underlying tissue from infection, dehydration, chemicals and mechanical stress...
(hyperkeratosis), thickening of the stratum spinosum
Stratum spinosum
The stratum spinosum is a layer of the epidermis found between the stratum granulosum and stratum basale. This layer is also referred to as the "spinous" or "prickle-cell" layer. This appearance is due to desmosomal connections of adjacent cells. Keratinization begins in the stratum spinosum....
(acanthosis), thickening of the stratum granulosum
Stratum granulosum
The stratum granulosum is a thin layer of cells in the epidermis. Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer...
, rete ridge elongation, and large 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...
s at the dermal-epidermal junction.
Prevention
GardasilGardasil
Gardasil , also known as Gardisil or Silgard, is a vaccine for use in the prevention of certain types of human papillomavirus , specifically HPV types 6, 11, 16 and 18. HPV types 16 and 18 cause an estimated 70% of cervical cancers, and are responsible for most HPV-induced anal, vulvar, vaginal,...
is a HPV vaccine
HPV vaccine
The human papilloma virus vaccine prevents infection with certain species of human papillomavirus associated with the development of cervical cancer, genital warts, and some less common cancers...
aimed at preventing cervical cancers and genital warts. Gardasil
Gardasil
Gardasil , also known as Gardisil or Silgard, is a vaccine for use in the prevention of certain types of human papillomavirus , specifically HPV types 6, 11, 16 and 18. HPV types 16 and 18 cause an estimated 70% of cervical cancers, and are responsible for most HPV-induced anal, vulvar, vaginal,...
is designed to prevent infection with HPV
Human papillomavirus
Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes...
types 16, 18, 6, and 11. HPV types 16 and 18 currently cause about 70% of cervical cancer
Cervical cancer
Cervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
cases, and also cause some vulvar
Vulvar cancer
Vulvar cancer, a malignant invasive growth in the vulva, accounts for about 4 % of all gynecological cancers and typically affects women in later life. It is estimated that in the United States in 2006 about 3,740 new cases will be diagnosed and about 880 women will die as a result of vulvar cancer...
, vaginal
Vaginal cancer
Vaginal cancer is any type of cancer that forms in the tissues of the vagina. Primary vaginal cancer is rare in the general population of women and is usually a squamous carcinoma. Metastases are more common. Vaginal cancer occurs more often in women over age 50, but can occur at any age, even in...
, penile and anal cancer
Anal cancer
Anal cancer is a type of cancer which arises from the anus, the distal orifice of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer. The etiology, risk factors, clinical progression, staging, and treatment are all different. Anal cancer is typically a...
s. HPV types 6 and 11 are responsible for 90% of documented cases of genital warts. Unfortunately the HPV vaccines do not currently prevent the virus strain responsible for verrucas.
Treatment
There are many different treatments and procedures associated with wart removal. One review of 52 clinical trials of various cutaneous wart treatments concluded that topical treatments containing salicylic acidSalicylic acid
Salicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
were the best supported, with an average cure rate of 75%, compared with 48% for the placebo in six placebo-controlled trials including a total of 376 participants.It can also be controlled by laser therapy The reviewers also concluded that there was little evidence of a significant benefit of cryotherapy
Cryotherapy
Cryotherapy is the local or general use of low temperatures in medical therapy or the removal of heat from a body part. The term "cryotherapy" comes from the Greek cryo meaning cold and the word therapy meaning cure...
over salicylic acid or duct tape.
One complicating factor in the treatment of warts is that the wart may regrow after it has been removed.
Medication
- Application of podophyllumPodophyllumPodophyllum is a genus of six species of herbaceous perennial plants in the family Berberidaceae, native to eastern Asia and eastern North America...
resin paint [podophyllum resin I.P.'66 (20% w/v), benzoin I.P. (10% w/v), aloes I.P. (2% w/v), isopropyl alcohol I.P. to make (100% v/v)] - ImiquimodImiquimodImiquimod is a prescription medication that acts as an immune response modifier. It is marketed by Meda AB, Graceway Pharmaceuticals and iNova Pharmaceuticals under the trade names Aldara and Zyclara, and by Mochida as Beselna. It is also referred to as R-837.- History :The original FDA approval...
, a topical cream that helps the body's immune system fight the wart virus by encouraging interferonInterferonInterferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...
production. Approved by the U.S. Food and Drug Administration (FDA) for genital warts. The drug is very expensive. - CantharidinCantharidinCantharidin, a type of terpenoid, is a poisonous chemical compound secreted by many species of blister beetle, and most notably by the Spanish fly, Lytta vesicatoria. The false blister beetles and cardinal beetles also have cantharidin.-History:...
, a chemical found naturally in many members of the beetle family Meloidae which causes dermal blistering. Either used by itself or compounded with podophyllinPodophyllinPodophyllin is a resinous powder obtained by precipitating an alcoholic tincture of the rhizome of American Mayapple or Podophyllum emodi by means of water acidified with hydrochloric acid. It varies in color from grayish to bright yellow or greenish-brown, the first-named being the purest...
. Not FDA approved, but available through Canada or select US compounding pharmacies. - BleomycinBleomycinBleomycin is a glycopeptide antibiotic produced by the bacterium Streptomyces verticillus. Bleomycin refers to a family of structurally related compounds. When used as an anticancer agent, the chemotherapeutical forms are primarily bleomycin A2 and B2. It works by causing breaks in DNA...
, not US FDA approved. One or two injections used. It can cause necrosis of digits and Raynaud syndrome. - DinitrochlorobenzeneDinitrochlorobenzene2,4-Dinitrochlorobenzene is a benzene derivative. It is an electrophilic, cytotoxic compound that is used in biochemical research involving glutathione-S-transferases .-Uses:...
(DNCB), like salicylic acidSalicylic acidSalicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
, this is applied directly to the wart. Studies showed this method was effective with a cure rate of 80%. But DNCB must be used much more cautiously than salicylic acid; the chemical is a known mutagen, able to cause genetic mutations. So a physician must administer DNCB. This drug induces an allergic immune response resulting in inflammation that wards off the wart-causing virus. - FluorouracilFluorouracilFluorouracil is a drug that is a pyrimidine analog which is used in the treatment of cancer. It is a suicide inhibitor and works through irreversible inhibition of thymidylate synthase. It belongs to the family of drugs called antimetabolites...
, which inhibits DNA synthesis, is being used as an experimental treatment. It is applied directly to the wart (especially plantar warts) and covered (for example: with tape). This treatment is combined with the use of a pumice stone, but tends to work very slowly. - Salicylic acidSalicylic acidSalicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
can be prescribed by a dermatologist in a higher concentration than that found in over-the-counter products. Examples include a topical solution marketed by EloracEloracElorac, Inc. is a specialty pharmaceutical company focused on advancing treatments in dermatology. It is based in Vernon Hills, Illinois. According to the company’s website, Elorac specializes in prescription based dermatology products, with a focus on medications used in the treatment of...
, Inc. under the trade name Durasal.
There are several over-the-counter
Over-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
options. The most common ones involve salicylic acid
Salicylic acid
Salicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
. These products are readily available at drugstore
Pharmacy
Pharmacy is the health profession that links the health sciences with the chemical sciences and it is charged with ensuring the safe and effective use of pharmaceutical drugs...
s and supermarket
Supermarket
A supermarket, a form of grocery store, is a self-service store offering a wide variety of food and household merchandise, organized into departments...
s. There are typically two types of products: adhesive pads treated with salicylic acid or a bottle of concentrated salicylic acid solution. Removing a wart with salicylic acid can be done by cleaning the area, applying the acid, and removing the dead skin with a pumice
Pumice
Pumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid...
stone or emery board. It may take up to a year to remove a wart.
Another product available over-the-counter that can aid in wart removal is silver nitrate
Silver nitrate
Silver nitrate is an inorganic compound with chemical formula . This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides...
in the form of a caustic pencil
Caustic pencil
A caustic pencil is a short stick of medication usually containing silver nitrate, used to cauterize skin, for instance for the removal of warts, or moles. They are not used as a treatment for minor cuts...
, which is also available at drug stores. In a placebo-controlled study of 70
patients, silver nitrate given over nine days resulted in clearance of all warts in 43% and improvement in warts in 26% one month after treatment compared to 11% and 14%, respectively, in the placebo group. The instructions must be followed to minimize staining of skin and clothing. Occasionally pigmented scars may develop.
Cryosurgery
Cryosurgery
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
or cryotherapy
Cryotherapy
Cryotherapy is the local or general use of low temperatures in medical therapy or the removal of heat from a body part. The term "cryotherapy" comes from the Greek cryo meaning cold and the word therapy meaning cure...
devices using a dimethyl ether - propane mixture are inexpensive. A disadvantage is that the sponge applicator is too large for small warts, and the temperature achieved is not nearly as low as with liquid nitrogen. Complications include blistering of normal skin if excess freezing is not controlled.
Several randomized controlled trials have found that zinc sulfate
Zinc sulfate
Zinc sulfate is the inorganic compound with the formula ZnSO4 as well as any of three hydrates. It was historically known as "white vitriol". It is a colorless solid that is a common source of soluble zinc ions.-Production and reactivity:...
, consumed orally, can bring to the disappearance of warts, using typically about 2.5 mg/kg/day elemental zinc (large amounts of zinc may cause a copper deficiency). Other trials have found that topical
Topical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
zinc sulfate solution or zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
are also effective.
Procedures
- Keratolysis, of dead surface skin cells usually using salicylic acidSalicylic acidSalicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...
, blistering agents, immune system modifiers ("immunomodulators"), or formaldehydeFormaldehydeFormaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
, often with mechanical paring of the wart with a pumice stone, blade etc. - Electrodesiccation
- CryosurgeryCryosurgeryCryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
, which involves freezing the wart (generally with liquid nitrogenLiquid nitrogenLiquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...
), creating a blister between the wart and epidermal layer, after which the wart and surrounding dead skin falls off by itself. An average of 3 to 4 treatments are required for warts of thin skin. Warts on calloused skin like plantar warts might take dozens or more treatments. - Surgical curettageCurettageCurettage, in medical procedures, is the use of a curette to remove tissue by scraping or scooping.Curettages are also a declining method of abortion. It has been replaced by vacuum aspiration over the last decade....
of the wart; - LaserLaserA laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
treatment - often with a pulse dye laser or carbon dioxide (CO2) laser. Pulse dye lasers (wavelength 582 nm) work by selective absorption by blood cells (specifically haemoglobin). CO2 lasers work by selective absorption by water molecules. Pulse dye lasers are less destructive and more likely to heal without scarring. CO2 laser works by vaporizing and destroying tissue and skin. Laser treatments can be painful, expensive (though covered by many insurances), and can cause little scarring when used appropriately. CO2 lasers will require local anaesthetic. Pulse dye laser treatment does not need conscious sedation nor local anesthetic. It takes 2 to 4 treatments but can be many more for extreme cases. Typically, 10-14 days are required between treatments. Preventative measures are important. - Infrared coagulator - an intense source of infrared light in a small beam like a laser. This works essentially on the same principle as laser treatment. It is less expensive. Like the laser, it can cause blistering pain and scarring.
- Duct tape occlusion therapyDuct tape occlusion therapyDuct tape occlusion therapy : is a method for treating warts by keeping them covered with duct tape for an extended period. The putative mechanism is not well understood and is likely a result of stimulation of the host immune system...
(DTOT) involves placing a piece of duct tapeDuct tapeDuct tape, or duck tape, is cloth- or scrim-backed pressure sensitive tape often sealed with polyethylene. It is very similar to gaffer tape but differs in that gaffer tape was designed to be cleanly removed, while duct tape was not. It has a standard width of and is generally silver or black...
over the wart. The evidence as to whether or not it is effective is poor.
External links
- Wart photo library, Dermnet