Hypertrophic Scar
A raised, thickened scar that stays within the wound's borders
Quick Facts
- Type: Skin scar
- Cause: Excess collagen during wound healing
- Key feature: Raised but stays within wound borders
- Often improves: Gradually over months to years
Overview
A hypertrophic scar is a raised, thickened scar that forms when the body lays down extra collagen while healing a wound. Unlike a normal flat scar, it sits above the level of the surrounding skin and may look red, firm, or shiny. A defining feature is that it stays within the original boundaries of the wound and does not grow beyond it.
This is what separates a hypertrophic scar from a keloid, which spreads outward into healthy skin. Hypertrophic scars are common after burns, surgery, or injuries across areas of tension. Many gradually flatten and fade over months to years, and several treatments can speed improvement and ease itching or tightness.
Symptoms
A hypertrophic scar typically shows:
- A raised, firm area of scar tissue over a healed wound
- Red, pink, or purplish color that may fade with time
- Itching or tenderness, especially in the early months
- A tight or pulling sensation, particularly over joints
- Scar that remains within the edges of the original wound
Over a joint or area that moves, a thick scar can occasionally limit movement, which is one reason early treatment of burn scars matters.
Causes
Hypertrophic scars form when the normal wound-healing process produces too much collagen:
- Excess collagen: During healing, repair cells overproduce collagen, raising the scar above the skin.
- Tension on the wound: Scars across areas of movement or stretch are more likely to thicken.
- Delayed or complicated healing: Wound infection, poor wound care, or prolonged inflammation increases the risk.
Burns, surgical incisions, deep cuts, and injuries that heal slowly are common starting points.
Risk Factors
- Burns, especially deep or large ones
- Wounds over high-tension areas such as the chest, shoulders, and joints
- Wound infection or delayed healing
- Younger age, when healing is more active
- A previous tendency to form thick or raised scars
- Wounds left to heal without good care
Diagnosis
Hypertrophic scars are usually diagnosed by appearance and history:
- Visual examination: A raised, firm scar confined to the original wound border is characteristic.
- History: A link to a prior burn, surgery, or injury supports the diagnosis.
- Distinguishing from keloid: The key point is whether the scar stays within the wound edges (hypertrophic) or grows beyond them (keloid).
A biopsy is rarely needed but may be done if the diagnosis is uncertain.
Treatment
Many hypertrophic scars improve on their own, and several treatments can flatten and soften them:
- Silicone gel or sheets: A common first-line option that, used consistently, can flatten and soften scars over months.
- Pressure therapy: Pressure garments are often used for burn scars.
- Steroid injections: Corticosteroid injected into the scar can reduce its thickness and ease itching.
- Massage and moisturizing: May help comfort and flexibility.
- Laser therapy: Can improve redness and texture.
- Surgical revision: Reserved for selected scars, sometimes combined with other treatments to lower the chance of recurrence.
Protecting the scar from sun helps prevent it from darkening while it matures.
Prevention
- Keep wounds clean and follow good wound care to avoid infection
- Use silicone gel or sheets early on high-risk wounds, as advised
- Reduce tension on healing wounds; follow surgical aftercare instructions
- Protect healing scars from the sun
- Seek prompt care for burns to support better healing
When to See a Doctor
See a doctor or dermatologist if a scar:
- Becomes raised, thick, itchy, or painful
- Limits movement over a joint
- Is cosmetically distressing or affects a visible area
- Continues to grow or spreads beyond the wound edges, which may suggest a keloid
- Shows signs of infection such as increasing redness, warmth, or drainage
Early treatment generally gives better results, so it is worth seeking advice while a scar is still developing.
Frequently Asked Questions
What is the difference between a hypertrophic scar and a keloid?
Both are raised, thickened scars, but a hypertrophic scar stays within the borders of the original wound, while a keloid grows beyond them into surrounding healthy skin. Keloids also tend to be more persistent and harder to treat.
Do hypertrophic scars go away on their own?
Many hypertrophic scars gradually flatten and fade over months to years without treatment. Silicone gel, pressure, steroid injections, and other therapies can speed improvement and relieve itching, tightness, or discomfort.
What is the best treatment for a hypertrophic scar?
Silicone gel or sheets used consistently are a common first-line treatment, and steroid injections, pressure garments, laser, and massage are also used. The best choice depends on the scar's size, location, and symptoms, so a clinician can tailor a plan.
Can I prevent a hypertrophic scar?
You cannot always prevent one, but good wound care, avoiding infection, reducing tension on the wound, and early use of silicone gel on high-risk wounds can lower the risk. Protecting the scar from the sun also helps it heal with a better appearance.
Are hypertrophic scars harmful?
They are not dangerous, but they can cause itching, tightness, or discomfort, and a thick scar over a joint may limit movement. Many people also seek treatment for cosmetic reasons, which is reasonable and often effective.
References
- American Academy of Dermatology Association. Scars.
- MedlinePlus, U.S. National Library of Medicine. Scars.
- Merck Manual. Keloids and Hypertrophic Scars.
- StatPearls, National Library of Medicine. Hypertrophic Scarring.