Scars are a normal part of healing, but some go through a more exuberant process than others. Two types in particular — keloid and hypertrophic scars — raise above the skin surface and can cause significant discomfort and cosmetic concern.

These two scar types look similar at first glance, and the terms are often used interchangeably, but they behave very differently. Telling them apart matters because it influences which treatments are likely to help.

What is a hypertrophic scar?

A hypertrophic scar is a raised, firm, pink or red scar that forms within the boundary of the original wound. It is essentially an over-enthusiastic healing response: collagen is laid down faster than it is broken down, producing a thickened scar that sits proud of the surrounding skin. The key feature is that a hypertrophic scar, although raised, respects the edges of the injury.

Hypertrophic scars often appear in the first few weeks after a wound heals, peak between three and six months, and then slowly soften and flatten over one to two years. Many improve substantially with time and simple measures.

What is a keloid scar?

A keloid behaves differently. It is a benign but invasive overgrowth of scar tissue that extends beyond the edges of the original wound into previously healthy skin. Keloids can continue to grow for months or years, are often firm and rubbery, may itch or feel tender, and rarely regress on their own. Unlike hypertrophic scars, they do not typically fade with time.

"The simplest way to remember the difference is this: a hypertrophic scar stays inside the lines. A keloid doesn't."

Who is at risk?

Both scar types are more common in certain groups, and understanding risk factors helps guide prevention and counselling.

  • Skin type: darker skin types (Fitzpatrick IV to VI) are significantly more prone to keloids.
  • Age: young adults between 10 and 30 are at the highest risk.
  • Family history: a strong genetic component, particularly for keloids.
  • Location: high-tension areas such as the chest, shoulders, upper back and earlobes (after piercings) are classic sites.
  • Wound factors: infection, delayed healing and tension across the wound all increase the risk.

Treatment options

Treatment is generally stepped, starting with the simplest measures and escalating as needed. No single treatment is right for every patient, and combination approaches often give the best results.

First-line: silicone and pressure

  • Silicone sheets and gels: the most evidence-based non-invasive option. Worn or applied daily for three to six months, they help flatten and soften scars.
  • Pressure therapy: particularly useful after burns and for earlobe keloids, where custom pressure clips can be effective.
  • Massage and moisturisation: simple but helpful adjuncts once wounds are fully healed.

Intralesional steroid injections

Injections of steroid directly into the scar can flatten and soften both hypertrophic scars and keloids. A series of treatments spaced six to eight weeks apart is typical. Side effects can include skin thinning, pigmentation changes and small blood vessels appearing around the injection site, so careful technique matters.

Surgical revision

Surgery can be appropriate for hypertrophic scars that have failed conservative treatment, and for selected keloids — but keloids carry a high recurrence risk if excised alone. For this reason, surgery for keloids is almost always combined with another modality, such as post-operative steroid injections or low-dose radiotherapy.

Adjunct treatments

  • Radiotherapy: used selectively after keloid excision in high-risk sites, and delivered in low doses by a radiation oncologist.
  • Cryotherapy: freezing treatment that can flatten smaller keloids, sometimes combined with injections.
  • Laser therapy: helpful for reducing redness and improving texture in selected scars.

When to seek specialist help

If a scar is growing beyond the original wound, if it is painful, itchy or interfering with movement, or if it has not improved after several months of silicone therapy, a specialist assessment is worthwhile. An early, tailored plan is almost always more effective than a late one. If you would like to discuss scar management options, please contact the clinic to arrange a consultation.

Mr Masha Singh

MBBS BSc(Hons) MSc(Surg Sci) FRCS(Plast)

Consultant Plastic, Reconstructive and Aesthetic Surgeon with a specialist interest in skin health and skin oncology. Trained at St George's Hospital Medical School and the Royal Marsden Hospital, Mr Singh works privately and within the NHS across London.