A
keloid (also known as a "keloidal scar") is a type of
scarScars are areas of fibrous tissue that replace normal skin after injury. A scar results from the biologic process of wound repair in the skin and other tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound Scars (also...
, which depending on its maturity, is composed of mainly either type III (early) or type I (late)
collagenCollagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content. It is naturally found exclusively in metazoa, including sponges. In muscle tissue it serves as a major component of endomysium...
. It is a result of an overgrowth of granulation tissue (collagen type 3) at the site of a healed skin injury which is then slowly replaced by collagen type 1. Keloids are firm, rubbery lesions or shiny, fibrous
nodulesFor use of the term nodule in dermatology, see Nodule In medicine, a nodule refers to a relatively hard, roughly spherical abnormal structure....
, and can vary from pink to flesh-colored or red to dark brown in color. A keloid scar is
benignA benign tumor is a tumor that lacks all three of the malignant properties of a cancer. Thus, by definition, a benign tumor does not grow in an unlimited, aggressive manner, does not invade surrounding tissues, and does not metastasize...
, non-contagious, and usually accompanied by severe itchiness, sharp pains, and changes in texture. In severe cases, it can affect movement of skin.
Keloids should not be confused with hypertrophic scars, which are raised scars that do not grow beyond the boundaries of the original wound.
Occurrence
Keloids expand in claw-like growths over normal skin. They have the capability to hurt with a needle-like pain or to itch without warning, although the degree of sensation varies from patient to patient.
If the keloid becomes infected, it may ulcerate. The only treatment is to remove the scar completely. However, the probability that the resulting surgery scar will also become a keloid is high, usually greater than 50%.
Keloids form within
scar tissueScars are areas of fibrous tissue that replace normal skin after injury. A scar results from the biologic process of wound repair in the skin and other tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound Scars (also...
.
CollagenCollagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content. It is naturally found exclusively in metazoa, including sponges. In muscle tissue it serves as a major component of endomysium...
, used in wound repair, tends to overgrow in this area, sometimes producing a lump many times larger than that of the original scar. Although they usually occur at the site of an injury, keloids can also arise spontaneously. They can occur at the site of a piercing and even from something as simple as a pimple or scratch. They can occur as a result of severe
acneAcne vulgaris is a common skin condition, caused by changes in pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland, via androgen stimulation. It is characterized by noninflammatory follicular papules or comedones and by inflammatory papules,...
or
chickenpoxChickenpox or chicken pox, also known as varicella, is a highly contagious illness caused by primary infection with varicella zoster virus...
scarring, infection at a wound site, repeated trauma to an area, excessive skin tension during wound closure or a foreign body in a wound. Keloids can sometimes be sensitive to chlorine.
Biologically, keloids are fibrotic tumors characterized by a collection of atypical fibroblasts with excessive deposition of extracellular matrix components, especially collagen, fibronectin, elastin, and proteoglycans. Generally, keloids contain relatively acellular centers and thick, abundant collagen bundles that form nodules in the deep dermal portion of the lesion. Keloids present a therapeutic challenge that must be addressed, as these lesions can cause significant pain, pruritus (itching), and physical disfigurement. They may not improve in appearance over time and can limit mobility if located over a joint.
Keloids affect both sexes equally, although the incidence in young female patients has been reported to be higher than in young males, probably reflecting the greater frequency of earlobe piercing among women.
There is a fifteen times higher frequency of occurrence in highly pigmented people. It is speculated that people who possess any degree of African descent, regardless of skin color, may be especially susceptible to keloid occurrences.
History in medicine
Keloids were described by Egyptian surgeons around 1700 BC.
Baron Jean-Louis AlibertJean-Louis-Marc Alibert was a French dermatologist born in Villefranche-de-Rouergue, Aveyron. He was a pioneer of French dermatology....
(1768-1837) identified the keloid as an entity in 1806. He called them
cancroide, later changing the name to
cheloide to avoid confusion with cancer. The word is derived from the Greek
chele, meaning crab's claw, and the suffix
-oid, meaning like. For many years, Alibert's clinic at L'Hôpital Saint-Louis was the world’s center for
dermatologyDermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. The name of this specialty originated in the form of the words dermologie and, a little later, dermatologia...
.
Intentional keloids
The
OlmecThe Olmec were an ancient Pre-Columbian civilization living in the tropical lowlands of south-central Mexico, in what are roughly the modern-day states of Veracruz and Tabasco....
of Mexico in
pre-ColumbianThe Pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic to European colonization during the...
times used keloid
scarificationFor the process that encourages germination in plants see Scarification .Scarifying involves scratching, etching, or some sort of superficial cutting or incision as a permanent body modification, etching designs, pictures, or words into the skin....
as a means of decoration. In the modern era, women of the
NubiaNubia is the region in the south of Egypt, along the Nile and in northern Sudan. Most of Nubia is situated in Sudan with about a quarter of its territory in Egypt...
-
KushThe Kingdom of Kush or Cush was an ancient African state centered on the confluences of the Blue Nile, White Nile and River Atbara in what is now the Republic of Sudan. It was one of the earliest civilizations to develop in the Nile River Valley...
in
SudanSudan is a country in northeastern Africa. It is the largest country in Africa and in the Arab World, and tenth largest in the world by area...
are intentionally scarified with facial keloids as a means of decoration. The
NuerThe Nuer are a confederation of tribes located in Southern Sudan and western Ethiopia. Collectively, the Nuer form one of the largest ethnic groups in East Africa....
and
NubaNuba is a collective term used here for the peoples who inhabit the Nuba Mountains, in the states of Southern Sudan, Africa. Although the term is used to describe them as if they composed a single group, the Nuba are multiple distinct strains and speak different kindss of language...
use lip plugs, keloid tattoos along the forehead, keloid tattoos along the chin and above the lip, and cornrows. As a part of a ritual, the people of Papua, New Guinea cut their skin and insert clay or ash into the wounds so as to develop permanent bumps (known as keloids or weals). This painful ritual honors members of their tribe who are celebrated for their courage and endurance.
Locations of keloids
Keloids can develop in any place that an abrasion has occurred. They can be the result of pimples, insect bites, scratching, burns, or other skin trauma. Keloid scars can develop after surgery.
They are more common in some sites such as central chest, the back and shoulders and the ear lobes.
Incidence
People of all ages can develop a keloid. Children under 11 are less likely to develop keloids, even when they get their ears pierced. Keloids may also develop from
pseudofolliculitis barbaePseudofolliculitis barbae is a medical term for persistent irritation caused by shaving. The etymology comes from "pseudo" "follicle" "itis" "barbae"...
, continued shaving when one has razor bumps will cause irritation to the bumps, infection and over time keloids will form. It would thus be wise for a man with razor bumps to stop shaving for a while and have the skin repair itself first before undertaking any form of hair removal. It is also speculated that the tendency to form keloids is hereditary and may be passed down from generation to generation.
Treatments
No treatment for keloids is considered to be 100% effective. Some of the treatments that are currently available are described below. These treatments have varying degrees of effectiveness. All the invasive methods of treatment like surgery carry a serious risk of the keloid recurring and becoming bigger than it previously was.
- Mederma
Mederma is an onion-extract-based topical gel produced by Merz Pharmaceuticals of Greensboro, North Carolina. Mederma's marketing claims it can make scars "softer, smoother, and less noticeable". A 2006 published peer reviewed research article indicated no statistically significant change in...
— Contains allium cepa.
- Contractubex Gel / Hexilak Gel — These gels contain allium cepa
Onion is a term used for many plants in the genus Allium. They are known by the common name "onion" but, used without qualifiers, it usually refers to Allium cepa. Allium cepa is also known as the "garden onion" or "bulb" onion...
extract, heparin and allantoin. Developed for the treatment of post-thyroidectomy scars, these gels are now indicated for the treatment of all post traumatic (burns, acne, piercings) or post surgery scars and keloids. Treatment is simple but requires perseverance. The earlier the initiation of treatment, the better the prognosis.
- Natural treatments — Some scar treatments contain mucin from the snail helix aspersa müller. The secretion from the snail regulates the skin healing and scar formation process. Topical application of treatments with this ingredient on keloid scars regulates and/or decreases dermal fibroblast proliferation and excess collagen production, and thus prevents and reduces keloid scars and hyperthropic scars.
- Surgery — Surgery
Surgery is a medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, to help improve bodily function or appearance, or sometimes for some other reason...
requires great care during and after the operation. Keloids that return after being excised may be larger than the original. There is a 50% chance of recurrence after surgical removal. However, keloids are less likely to return if surgical removal is combined with other treatments. Surgical or laser excision may be followed by intralesional injections of a corticosteroid. Plastic closure of the skin including techniques such as v-plasty or w-plasty to reduce skin tension are known to reduce recurrence of keloids following excisionExcision means "to remove by cutting".* In surgery, an excision is the complete removal of an organ, tissue, or tumor from a body, as opposed to a biopsy. An "excisional biopsy" is the removal of a tumor with a minimum of healthy tissue...
.
- Dressings
A dressing is an adjunct used by a person for application to a wound to promote healing and/or prevent further harm. A dressing is designed to be in direct contact with the wound, which makes it different from a bandage, which is primarily used to hold a dressing in place...
— Moistened wound coverings made of silicone gel (such as Dermatix) or silasticSilastic is a trademark registered in 1948 by Dow Corning Corporation for flexible, inert silicone elastomer...
have been shown in studies to reduce keloid prominence over time. This treatment is safe and painless, although some patients may experience increased itchiness from wearing the dressing for an extended period of time.
- Steroid injections — Steroid
A steroid is a terpenoid lipid characterized by its sterane core and additional functional groups. The core is a carbon structure of four fused rings: three cyclohexane rings and one cyclopentane ring. The steroids vary by the functional groups attached to these rings and the oxidation state of the...
injections are best used as the scar begins to thicken or if the person is a known keloid former. A series of injections with triamcinolone acetonideTriamcinolone acetonide is a more potent type of triamcinolone, being about 8 times as effective as prednisone. Triamcinolone acetonide should not be used by those with tuberculosis or untreated fungal, bacterial, viral or herpes infections without consulting a doctor first. Very few side effects...
or another corticosteroidCorticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
may reduce keloid size and irritation. However, injections are often uncomfortable and in large and/or hard scars can be difficult to perform, requiring local anesthetic for people over 16, and full anesthetic for people under. The treatment area can become very painful as the anesthetic wears off.
- Compression — Compression bandages applied to the site over several months, sometimes for as long as six to twelve months, may lead to a reduction in the size of the keloid. This is the best treatment for preventing new scars.
- 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"....
is an excellent treatment for keloids which are small and occur on lightly pigmented skin. It is often combined with monthly cortisone injections. The use of cryotherapy is limited since it causes skin blanching. It freezes the skin and causes sludging of the circulation beneath, effectively creating an area of localized frostbite. There is a slough of skin and keloid with re-epithelization.
- Radiation therapy
Radiation therapy is the medical use of ionizing radiation as part of cancer treatment to control malignant cells . Radiotherapy may be used for curative or adjuvant cancer treatment...
— Electron beam radiation can be used at levels which do not penetrate the body deeply enough to affect internal organs. Orthovoltage radiationOrthovoltage X-rays are produced by X-ray generators operating at voltages in the 200–500 kV range, and therefore an energy in the 200–500 keV range . When used to treat patients, radiation oncologists find that they penetrate to a useful depth of about 4–6 cm...
is more penetrating and slightly more effective. Radiation treatments reduce scar formation if they are used soon after a surgery while the surgical wound is healing. This is one of the most effective procedures.
- Laser
A laser is a device that emits light through a process called stimulated emission. Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses...
therapy — This is an alternative to conventional surgery for keloid removal. Lasers produce a superficial peel but often do not reduce the bulk of the keloid. The use of dye-tuned laserA dye laser is a laser which uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths. The wide bandwidth makes them particularly suitable for tunable lasers and...
s has not shown better results than that of cold lasers. A relatively new approach is to combine laser therapy with steroid injections.
- Newer treatments — Drugs that are used to treat autoimmune diseases
Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
or cancerCancer is a class of diseases in which a group of cells display uncontrolled growth , invasion , and sometimes metastasis...
have shown promise. These include alpha-interferon, 5-fluorouracil and bleomycinBleomycin is a glycopeptide antibiotic produced by the bacterium Streptomyces verticillus. Bleomycin refers to a family of structurally related compounds. When used as an anti-cancer agent, the chemotherapeutical forms are primarily bleomycin A2 and B2. Bleomycin...
. However, there is a need for further study and evaluation of this treatment technique.
Case presentation
This is a young male with bilateral keloid formation on the plantar surfaces of both feet. He has never been treated for this condition. There are other much smaller keloids located at small inlets on the glabrous (hairless) skin.
External links