Keloid, Hypertrophic and Other Types of Scars

Scar Types

Hypertrophic Scars

Keloids

Atrophic Scars

Scar Types

Scars are not all alike. The particular kind of scar you have will be one of the factors that determines which scar-reducing treatment is right for you.

Hypertrophic Scars

These scars look like thick, reddish lumps on the skin, although the redness may fade a bit with time. They’re caused by an overproduction of collagen, the protein fibers that the body generates to “fill in” a wound to the skin. Hypertrophic scars often itch, and if they’re located near a joint, they may constrict skin tissue and make movement of the joint more difficult.

Young people and those with darker skin are more likely to form hypertrophic scars. In addition, research suggests that some people may inherit a susceptibility to this type of raised scarring. Hypertrophic scars sometimes become smaller over time.

Keloids

Keloids are hypertrophic scars—that is, they’re reddish-purplish, raised and caused by an overproduction of collagen. Keloids, however, spread beyond the site of the original wound—into skin tissue that wasn’t part of the original injury. They are, in othe words, an exaggerated response to the injury. Although irregular in shape, keloids tend to have a smooth surface. They often itch and can even be painful, especially while they’re forming.

Although keloids can develop on any injured area of the body, they are most likely to appear on the chest, shoulders, back and earlobes. As with other hypertrophic scars, the tendency toward developing keloids seems to run in families. In susceptible people, these scars form not only after a traumatic skin injury, but sometimes after a minor injury to the skin, such as a scratch, a vaccination, or even an ear piercing. Keloids do not regress over time.

Atrophic Scars

Atrophic scars are those that leave a pit or depression in the skin. They occur when the injury to the skin has caused a loss of dermal tissue and the healing process does not produce enough collagen to replace the lost tissue. Atrophic scars are a common side effect of acne and other skin diseases.

Acne Scars

Acne can lead to the formation of hypertrophic and/or keloid scars—large, thick, reddish lumps on the skin. But most acne scars are atrophic—scars that leave indentations in the skin. They occur when inflammation caused by the acne destroys tissue in the dermis, the skin’s lower layer. Atrophic acne scars are classified into three main groups: ice pick (deep, narrow scars that look as if they’ve been punched with an icepick), boxcar (round or oval “craters” with vertical sides), and rolling (wave-like undulations across the skin’s surface).

An acne lesion may also leave behind a flat area of hyperpigmentation, but this discoloration tends to fade with time.

Contracture Scars

Contracture scars occur when a sufficiently large area of dermis has been lost to an injury (usually a burn) or when a wound occurs on a joint, such as the knee or elbow. The new collagen-rich skin that forms over the wound site becomes so thick and tight that it impedes movement. These scars often include damage to underlying muscles and tendons.

Stretch Marks

Although stretch marks (or striae, in medical lingo) may not meet the technical definition of scars, they do occur as the result of damage to the dermis, the skin’s thick underlying layer of tissue. In the case of stretch marks, the damage is to the elastin, or netlike fibers that give skin its elasticity. Despite their name, these marks are caused by fluctuating hormones, not stretching skin. Hormonal triggers include pregnancy; rapid weight gain or growth; and the use of birth control pills, steroids and other medications.

Treatments for Scars

All these scars—even very old ones—can be helped with the right treatment. New developments in laser therapies have proven especially effective in reducing the appearance of scars, even when they’re decades old. Talk with a physician who specializes in skin care about treatment options available for your scar.