Keloids are a form of abnormal wound healing characterized by an overgrowth of scar tissue. These raised scars develop following a skin injury and are distinct because they expand outside the original boundaries of the wound. While they are benign and do not pose a direct health threat, keloids can cause significant cosmetic concerns, along with symptoms like itching, pain, or a burning sensation. Understanding the unique appearance and underlying biology of these scars is the first step toward effective management.
Visual Characteristics and Differentiation
Keloids typically present as firm, rubbery, or shiny nodules significantly raised above the surrounding skin. They are dense and hard to the touch and may cause itchiness or tenderness. Their color varies, often appearing pink or red, but they can also be darker in individuals with more melanin. A defining characteristic is their tendency to grow laterally, extending into the healthy skin, sometimes resulting in a claw-like shape, which is how the condition received its name.
Keloids differ fundamentally from hypertrophic scars, which remain confined within the borders of the original wound and often flatten over time. Keloids, in contrast, do not regress spontaneously and can continue to grow for months or years after the initial trauma. This difference reflects a biological distinction involving the overproduction of collagen. Visually, keloids can also be distinguished by the presence of arborizing, or branching, blood vessels on their surface.
Underlying Causes and Risk Factors
Keloids form due to a malfunction in the natural wound healing process involving overactive fibroblasts. These cells synthesize excessive amounts of collagen and other components of the skin’s matrix. The resulting fibrous growth is a dense, disorganized accumulation of collagen bundles that pushes outward and expands beyond the injury site.
Genetic predisposition is the most significant factor in keloid formation. Individuals with a family history have a much higher likelihood of developing them. The condition shows a higher incidence in individuals with darker skin tones, including those of African, Asian, and Hispanic descent, suggesting a link with melanin and genetic factors.
Keloids can arise from any form of skin trauma or inflammation. Common triggers include surgical incisions, ear piercings, burns, deep cuts, severe acne, or chickenpox. The highest risk period is generally between the ages of 10 and 30. Certain body locations, such as the chest, shoulders, earlobes, and upper back, are more commonly affected than others.
Overview of Medical Treatments
Treating existing keloids can be challenging because they frequently recur, especially after surgical removal. Medical management often involves a combination of therapies to maximize the chance of a successful outcome. Consultation with a dermatologist is recommended to determine the best approach based on the keloid’s size, location, and the patient’s skin type.
Corticosteroid injections are frequently used as a first-line treatment. These intralesional injections deliver a steroid directly into the scar tissue, reducing inflammation and slowing collagen production. Patients typically require a series of monthly injections before the keloid begins to flatten. Possible side effects include localized changes in skin color or thinning of the surrounding skin.
Cryotherapy, which involves freezing the keloid with liquid nitrogen, is an option for smaller growths. This method destroys the cells within the scar and reduces both size and firmness. Cryotherapy is often used in combination with corticosteroid injections, as freezing can make the injections more effective. However, it carries a risk of causing permanent light spots on the skin, especially in darker complexions.
Surgical excision, or cutting out the keloid, has a high risk of recurrence, with rates ranging from 45% to 100% if used alone. To prevent regrowth, surgery is almost always followed by an adjunctive therapy. These therapies include corticosteroid injections, pressure therapy, or radiation. Low-dose radiation therapy, applied shortly after surgery, is effective for reducing the chance of the keloid returning.
Laser therapy, often using a pulsed-dye laser, can flatten the scar tissue and reduce redness. This treatment is typically combined with other modalities, such as steroid injections, to improve the overall outcome. Non-invasive pressure therapy, using special garments or earrings, and the application of silicone sheets or gels are also employed to help flatten keloids and prevent recurrence.