Scars, hypertrophic scars and keloid scars

Scars are timeless records of our significant life events: the acne of youth, an accidental fall, a burn injury, or previous surgery are such examples. Scars may result in significant functional and aesthetic impairments; they may be itchy, painful, prominent and unsightly. They may affect one’s body image and self-confidence, and may carry the psychological burden of the initial injurious event. Scars may adversely affect individuals long after the initiating event; conversely, successful scar treatment may confer long-lasting functional and aesthetic benefits.


Keloid Surgery in Singapore

How do wounds normally heal?

Scars form as a response to skin injury. When the skin surface is breached, bleeding occurs and a blood clot forms. The clot contains platelets, which release various chemicals into the wound and initiate inflammation. The blood vessels around the wound dilate and white blood cells are attracted to the area. Macrophages (a specialized type of white blood cell) digest bacteria and foreign material, and clean up the wound. Macrophages also release various growth factors that attract fibroblasts (a specialized skin cell) to the wound and stimulate them to multiply.

Fibroblasts secrete large amounts of collagen into the wound, which consist of irregular bundles of type III collagen. The result is an immature scar, which has an appearance distinct from the surrounding skin. The rate of wound healing is dependent on the anatomical region of the body. In the face and neck, wounds are healed by days 5 to 7, whereas in the lower extremities, wounds take 21 or more days.

Scar remodelling is the final step in wound healing and happens months after the initial injury. Beneath the skin surface, fibroblasts digest the collagen within the immature scar, and replace it with parallel, regular bundles of type I collagen resembling that of normal skin. This explains why scars continue to evolve months after the initial injury and the scar gradually returns to the appearance similar to the surrounding skin.


What are keloid scars and hypertrophic scars?

Keloid scars and hypertrophic scars are abnormal scars. Following the initial injury, these scars become red, itchy, raised, painful, and may be exquisitely tender to touch. The symptoms may be severe and troubling to a point where it affects daily functioning. Under the microscope, these scars contain an abnormally high number of fibroblast cells and excessive amounts of collagen. This manifests as a protrusion above the skin surface and in the case of keloid scars, infiltrates the surrounding normal skin.

Formation of keloid scars is linked to a genetic tendency that is heritable. It is a common problem in many Asians, especially in individuals with darker skin pigmentation. Keloid scars have a propensity to form on the earlobes, neck, shoulder, chest, umbilicus and in pubic region.

Hypertrophic scars are also common. They tend to form in areas of high mobility, e.g. on the neck and at the joints such as the elbows and knees. It is thought that constant movement and tension forces perpendicular to the scar stimulates hypertrophic scar formation.

How do scars differ?

Keloids will grow beyond the boundary of the original wound or scar, whereas hypertrophic scars are confined to the original wound boundary. Keloid scars may grow years after the initial injury and very rarely undergo spontaneous resolution. Hypertrophic scars almost never occur more than a year after the initiating injury and may sometimes resolve with time.


Scar treatment is tailored to the individual scar characteristics and expectations. Tailoring the treatment approach produces optimal and bespoke outcomes.

Silicone gels and dressings

Silicone gel is a time-tested treatment for scars and is one of the most effective methods available.

Silicone gel works by several mechanisms: reduction of the transepidermal water loss over the scar, localized elevation of scar temperature relative to the surrounding skin and exerting a natural electrostatic charge of the silicone sheet on the scar. These act together to regulate fibroblast activity and reduce the amount of abnormal collagen produced in scars.

Silicone gels are colorless, odourless, and are particularly useful for treatment in these visible areas. In highly visible areas such as the face, neck and hands, the twice-daily use of topical cyclopentasiloxane (CPX) silicone gel is the ideal method of scar management. In areas that are concealed by clothing, reusable silicone sheets are equally effective. Compression garments deliver homogeneous, controlled pressure on the trunk and the extremities, and may be used over the silicone patch, for additional flattening of raised hypertrophic and keloid scars.

Steroid injection

Steroid injection directly into the scar is one of the most effective methods keloid and hypertrophic scar treatment.

Keloid and hypertrophic scars continue to have inflammation long after the wound has healed, resulting in prolonged stimulation of fibroblasts and collagen production. Steroids are effective anti-inflammatory medications that inhibit inflammation at multiple points along the pathway. The most effective route of steroid delivery is by injecting into the scar itself.

Intralesional steroid injections are simple ambulatory procedures. The dose of steroid used, and the number of injection points, vary from scar to scar, and from individual to individual. Local anesthesia may be administered in individuals whose keloids are exquisitely painful or tender.
Injection site pain is significantly reduced with the use of a proprietary pain distraction device at Picasso Plastic Surgery.

No special post-procedural care is required. Most individuals will experience a reduction of itch and pain within 48 hours of the steroid injection. The vast majority of keloids and hypertrophic scars require repeat steroid injections at 4- to 6- week intervals until the scars are flat and asymptomatic. Scars begin to flatten noticeably after the second or third treatment and are often accompanied by a reduction in redness of the scar.

Botulinum toxin injections

Botulinum toxin induces partial muscle weakness and reduces the wound tension around the scar. Botulinum toxin may be used in the prevention or treatment of hypertrophic scars.

How is botox administered?

The dose and dilution of botulinum toxin administered is adjusted to the individual scar characteristic and anatomy. Injection site pain is significantly reduced with the use of a proprietary pain distraction device.

Keloid & Hypertrophic Scars: Differences, Causes & Effective Treatments

Laser scar resurfacing

Fractional laser resurfacing technology uses microbeams of laser arranged in a grid pattern and delivers high-energy, tiny beams of laser light on the skin surface.  These beams create microthermal zones (MTZ), leaving normal skin in between the MTZ.  Microscopically, MTZs consists of cylinders of heated and stimulated skin, and are naturally extruded from the skin at about 1 to 2 weeks post-procedure, expelling the old, defective skin.  The adjacent normal skin contains stem cells, which multiply and heal over the extruded skin.  Fractional laser scar resurfacing strikes an optimal balance between clinical effect and recovery time.

The CO2 laser utilizes a 10,600-nm wavelength and penetrates to a depth of 200- to 300- micrometers within the skin or deeper. The fractional CO2 laser generates good collateral heating around the treated area and induces significant scar remodelling. Picasso Plastic Surgery utilizes the fractional CO2 laser to deliver the best result to you.

Fractional scar resurfacing is a quick and simple ambulatory procedure. An anesthetic cream is applied to provide analgesia during the procedure. The laser settings are tailored to individual scar characteristic and treatment goals. Successful laser treatment is a fine art that strikes a balance between delivering sufficient laser energy to create good clinical effect yet avoiding prolonged healing and complications.

Mild skin redness is expected over the treated areas, which peaks at about 24 hours and settles after 48 to 72 hours. Skin redness is due to blood vessel dilatation in the skin as a natural response to the laser treatment. Recovery after laser resurfacing is accelerated by the use of a proprietary serum derived from umbilical cord lining stem cell conditioned media for the first 5 days. Skin that has recently undergone laser treatment is normally sensitive to ultraviolet light, and will require generous use of sunblock after the skin surface is recovered at day 5. Repeat treatments may be performed at 4- to 6- week intervals for optimal results.

Scar excision surgery

Scar excision surgery is normally reserved for keloid scars that are partially- or non- responsive to steroid injections or scars that are too large for steroid injections. Scar excision surgery itself may serve as a stimulus for formation of another keloid scar. It is usual in most cases to undergo a few sessions of steroid injections prior to surgery to reduce scar activity and reduce the potential for keloid scar recurrence. Surgery is less often required for hypertrophic and normal scars.

Keloid scar excision is usually a minor surgery that may be performed as an ambulatory procedure under local anesthesia. The scar is excised down to its base, including some amount of subcutaneous fat. The underlying deep fascial tissue is stitched together to minimize the tension on the skin wound. The skin itself is meticulously stitched together with specialized techniques to maintain an optimal skin blood supply. This helps to minimize potential for recurrent postoperative keloid scar formation. Skin grafts are occasionally required following excision of large keloid scars.

Specialized adhesive dressings are usually placed on the wound to minimize and redistribute wound tension. Following removal of stitches, the wound is closely monitored for symptoms and signs of keloid recurrence including pain, itch, and lumpiness. Postoperative steroid injections may be required occasionally for prevention or treatment of recurrence.

Radiation therapy

Radiation therapy is an established treatment modality for keloid scars. Radiation induces controlled fibroblast cell death and reduces the activity of the remaining fibroblasts that survive. It is often used an adjunct treatment to steroid injections and/or surgery. A partnering radiation oncologist administers this radiotherapy treatment.

  • Individuals with recurrent keloids
  • Keloids unresponsive to other treatment methods
  • Individuals who are not agreeable for surgery
  • Individuals who have had keloid excision surgery but at high risk of recurrence

Radiotherapy is generally administered within 8 hours of the conclusion of keloid excision surgery for best results. Postoperative radiotherapy generally involves 3 daily sessions starting on the day of the surgery. Because of the time sensitivity required for effective treatment, private hospitals are the ideal setting for this modality of treatment.

Mild redness and blistering may occur in a minority of cases. These usually settle within 3 to 5 days. Short-term treatment with steroid creams is often helpful if symptoms are more severe. Individuals are closely monitored in the outpatient clinic for symptoms and signs of keloid recurrence.