A hypertrophic scar is a raised area of tissue with excess collagen that forms when a wound heals with collagen fibers forming in various directions rather than parallel to the skin's surface. They are more likely to form on areas where the skin is particularly tight or where there is more muscle tissues, such as the upper back, chest, and the backs of the shoulders. Asians, Hispanics, and blacks are more likely to develop these scars than Caucasians, though they occur in people of all races and ethnic backgrounds.
Wounds resulting from piercings and other forms of body modification often result in hypertrophic scars, though they usually get much smaller or heal completely if the jewelry is removed or changed to something lighter and less irritating. Nearly any type of wound can result in this kind of scar, particularly if there is a problem during the healing process. A wound that gets infected or is reopened may form this type of scar due to the disruption of the collagen fibers.
Keeping wounds clean and protected is the best way to reduce the risk of hypertrophic scars. Small foreign objects or bacteria that enter a wound could lead to infection or further trauma to the area, disrupting the body's natural healing process. Following a doctor's instructions for caring for a wound is also important. Wounds that heal slowly are more prone to scars and other forms of abnormal scarring.
Though some scars appear immediately after a wound heals, some raised scars do not develop until several weeks or months after healing. They may form gradually until reaching their full sizes. Treatment for this type of scar should be sought as soon as the person notices a raised area developing because treatment is much more likely to be successful if caught early. This kind of scar should never be lanced, popped, or cut open. Though it may resemble a pus-filled lesion, it is much stiffer and is filled with collagen and, in some cases, nerves.
Some people use the terms "hypertrophic scar" and "keloids" interchangeably, but the two conditions are slightly different. Hypertrophic scars are often smaller and lighter in color than keloids. Keloids are also painful for many people, while hypertrophic scars are usually not. These scars may be slightly tender, however, and they may also itch, develop a mild burning sensation, or be overly sensitive to the touch.