Keloids and Hypertrophic Scars: Why They Form and How They Are Treated

Keloids and hypertrophic scars are raised scars that develop when the skin produces extra collagen during healing. Although they are not dangerous, they may cause itching, tenderness, tightness, or cosmetic concern, and several treatment options can help flatten and soften them.

Overview

Keloids and hypertrophic scars are types of raised scars that occur when the skin’s normal repair process becomes overactive. After an injury, the body creates collagen to strengthen the healing area. In some people, too much collagen is produced or continues to build up for longer than needed, forming a thickened scar.

The two scar types look similar, but they behave differently. A hypertrophic scar is raised and firm but usually remains within the borders of the original cut, burn, or wound. A keloid grows beyond the original wound edges and can continue enlarging slowly over time. Both can appear after surgery, burns, acne, piercings, vaccinations, insect bites, or even minor scratches.

These scars are benign, meaning they are not cancer. However, they may cause discomfort, itching, sensitivity, tightness, or reduced movement if they form near a joint. They can also affect self-confidence, especially when they appear on visible areas such as the face, neck, chest, shoulders, or ears. The good news is that many treatments can improve texture, symptoms, and appearance, although raised scars often need patience and more than one treatment approach.

How Keloids and Hypertrophic Scars Differ

Understanding the difference between keloids and hypertrophic scars helps guide treatment. Hypertrophic scars usually develop within weeks after an injury or surgery. They may be red, pink, brown, or darker than the surrounding skin, and they can feel firm, itchy, or tender. Many hypertrophic scars gradually flatten and fade over months to years, especially when protected from sun exposure and supported with scar care.

Keloids may appear months after the initial injury and tend to grow outside the original wound. They can be smooth, shiny, rubbery, and raised. Their color may range from pink or red to brown or dark purple depending on skin tone and age of the scar. Keloids are more likely to recur after simple removal, which is why treatment plans often combine surgery with additional therapies when removal is appropriate.

Common areas for keloids include the earlobes, jawline, chest, upper back, shoulders, and upper arms. Hypertrophic scars can occur anywhere there is deeper skin injury, including surgical incisions and burn areas. A doctor can often distinguish the two by examining the scar’s shape, growth pattern, location, and history.

Symptoms and Appearance

Raised scars may cause no symptoms other than their appearance, but some people experience ongoing discomfort. The scar may feel itchy, sore, tight, or sensitive to pressure or clothing. In areas such as the shoulder, neck, chest, or elbow, the thickened tissue can pull on the surrounding skin and make movement less comfortable.

The appearance can vary widely. A scar may be small and dome-shaped, long and rope-like, or broad and firm. Early raised scars often look red or inflamed, while older scars may become lighter, darker, or more skin-colored. In darker skin tones, keloids may be more noticeable because of pigmentation changes, but raised scars can affect people of all skin tones.

Features that may suggest a keloid rather than a hypertrophic scar include growth beyond the original wound, continued enlargement over time, and a history of similar scars after small injuries. Features that may suggest a hypertrophic scar include a raised area that stays within the wound edges and slowly softens with time. Any scar that changes rapidly, bleeds without injury, ulcerates, or looks unusual should be assessed by a doctor to confirm the diagnosis.

Causes and Risk Factors

Keloids and hypertrophic scars form because wound healing involves inflammation, collagen production, and tissue remodeling. When this process is prolonged or unbalanced, collagen can accumulate excessively. This does not mean the wound was cared for incorrectly; some people are simply more prone to raised scarring because of genetics and skin biology.

Risk factors include a personal or family history of keloids, younger age, and darker skin types. Wounds in high-tension areas, such as the chest, shoulders, upper back, and jawline, are more likely to form thick scars because the skin is constantly pulled during movement. Infection, delayed healing, burns, acne inflammation, piercings, and repeated irritation may also increase scar activity.

Several common triggers may lead to raised scars, including:

• Surgical incisions, especially where the skin is under tension
• Ear or body piercings
• Acne, folliculitis, or ingrown hairs
• Burns, cuts, scrapes, or abrasions
• Vaccination sites or injections in susceptible individuals
• Skin trauma from tattoos or cosmetic procedures

People with known keloid tendency should discuss scar prevention before elective procedures, piercings, or cosmetic treatments. Preventive planning does not remove all risk, but it can reduce the chance of developing a thick, symptomatic scar.

Diagnosis

Diagnosis is usually made through a physical examination and medical history. The doctor will ask when the scar appeared, what caused the original wound, whether it has continued to grow, and whether similar scars have occurred in the past. The scar’s borders, firmness, color, tenderness, and location are also assessed.

In most cases, no special test is needed. However, if a lesion has an unusual appearance, is ulcerated, bleeds, grows very quickly, or does not match a typical scar pattern, the doctor may recommend further evaluation. Rarely, a small tissue sample may be taken to rule out other skin conditions.

A careful diagnosis is important because treatment differs depending on whether the scar is an active keloid, a hypertrophic scar, a mature flat scar, or another skin condition. It is also useful to assess the patient’s goals: some people mainly want itch relief, others want improved texture, and others are concerned about size, color, or location. A personalized plan is usually more effective than a single one-size-fits-all treatment.

Treatment Options

Treatment aims to flatten, soften, relieve symptoms, improve color or texture, and reduce the chance of recurrence. Results vary because scar biology differs from person to person. Raised scars often improve gradually over several sessions, and combination therapy is commonly recommended.

Non-surgical treatments are often tried first. Silicone gel or silicone sheets can help hydrate and protect the scar and may reduce thickness when used consistently. Pressure therapy, especially after ear keloid treatment or burns, can help control scar growth in selected cases. Intralesional corticosteroid injections are commonly used to reduce inflammation, itching, and thickness. Some specialists may combine steroids with other injectable medicines, such as 5-fluorouracil, depending on the scar and the patient’s health profile.

Procedure-based options may include cryotherapy, laser therapy, microneedling in selected scars, or surgical revision. Cryotherapy can shrink certain small keloids by freezing scar tissue, although pigmentation changes are possible. Vascular or fractional lasers may help with redness, thickness, tightness, or texture. Surgery can remove bulky scar tissue or revise a tight scar, but keloids have a higher risk of returning if surgery is used alone. For this reason, surgery is often paired with injections, silicone, pressure therapy, or, in carefully selected adult cases, superficial radiation therapy after excision.

The best plan depends on scar type, size, location, skin tone, previous treatments, symptoms, and medical history. A qualified dermatologist or plastic surgeon can explain expected benefits, possible side effects, number of sessions, and aftercare. Treatment should be realistic and focused on improvement rather than a guaranteed complete disappearance of the scar.

Prevention and Self-care

People who are prone to keloids or hypertrophic scars can lower risk by taking wound care seriously and seeking early advice for high-risk injuries. Clean wounds gently, follow medical instructions after surgery, and avoid picking scabs or squeezing inflamed acne. Reducing irritation and infection gives the skin the best chance to heal smoothly.

Sun protection is important for all scars. New scars can darken or remain discolored when exposed to ultraviolet light. Covering the scar with clothing or using a broad-spectrum sunscreen after the wound has fully closed can help reduce pigmentation changes. Moisturizing the surrounding skin and gentle massage may help some mature scars feel softer, but massage should not be used on open wounds or inflamed scars unless advised by a clinician.

For people with a known keloid tendency, prevention may include early silicone gel or sheets after the skin has closed, pressure earrings after earlobe procedures, and close follow-up after surgery. It may also be wise to avoid unnecessary piercings, tattoos, or elective skin procedures in areas where keloids commonly form. If a raised scar begins to thicken, itch, or extend beyond the wound, early treatment is often easier than treating a large, mature keloid later.

When to See a Doctor

A medical evaluation is recommended if a scar is growing beyond the original injury, becoming increasingly painful or itchy, limiting movement, or causing significant cosmetic concern. It is also important to seek care if a scar repeatedly opens, bleeds, becomes infected, or changes in an unusual way. Early assessment can help confirm the diagnosis and prevent worsening symptoms.

Patients should also speak with a doctor before elective surgery, piercings, tattoos, or cosmetic procedures if they have a personal or family history of keloids. Preventive planning may include incision placement, tension reduction, silicone therapy, pressure therapy, or early follow-up. These steps are especially important for areas such as the chest, shoulders, earlobes, and jawline.

Acıbadem Health Point’s multidisciplinary specialists and JCI-accredited hospitals diagnose and treat keloids and hypertrophic scars for international patients, including those who need dermatology, plastic surgery, laser treatment, or scar revision planning. A consultation with a qualified clinician can help patients understand safe options, likely timelines, and realistic goals for scar improvement.

Frequently asked questions