Keloid scars are common in general practice, affecting patients following surgery, trauma, or even arising spontaneously. While sometimes unavoidable, there’s a lot that can be done to improve outcomes.

Getting the diagnosis right

The first and most important step with any skin condition is arriving at the correct diagnosis. Once you have the correct diagnosis, you can be much more committed to your treatment pathway.

Keloid versus hypertrophic scars

Both keloid and hypertrophic scars are raised scars arising from similar traumas.

However, there’s a crucial difference: hypertrophic scars do not progress beyond the limits of the original injury, while keloid scars can actually spread and progress beyond these limits.

A classic example of keloid scarring is acne scarring on the chest that presents with claw-like extensions. You might see these finger-like projections extending laterally on either side, as if the scar is extending laterally. This pattern is pathognomonic for keloid scarring.

Common presentations and causes

Keloid scars can arise spontaneously or after various incidents on the skin. Common presentations include:

Acne-related scarring: Severe acne can lead to keloid scarring, generally on the chest but also sometimes on the upper back. These present as firm nodules or rope-like changes on the cheeks and jawline.

Post-surgical scarring: This is particularly relevant for GPs performing minor procedures, as we sometimes inadvertently cause keloid formation.

Genetic predisposition: Some patients simply have a genetic tendency toward keloid formation, regardless of the precipitating factor.

Risk factors

Recognising patients at higher risk for keloid formation allows you to tailor your surgical consent and approach accordingly.

Risk factors for keloid scarring include:

• darker skin types
• family history
• younger age

Keloid scars tend to occur more frequently in younger people compared with older people. This may be due to the increased elastin and collagen content and higher reparative capability in young people.

High risk parts of the body

Certain locations are particularly prone to keloid scarring.

The chest and shoulders are common areas, as well as the upper back. These high-movement areas are prone to develop raised or keloid scars due to the mechanical stress placed on healing tissue from large muscle groups in these locations.

Consider a female patient with skin cancer on the chest who has a family history of keloid scars, or someone whose previous caesarean section resulted in a raised scar. These scenarios should raise the priority of keloid prevention in your surgical planning.

Differential diagnosis and when to biopsy

While the diagnosis is generally fairly clear when patients provide a good history, there are important mimickers to consider.

Benign mimickers

Dermatofibromas and calcifications underneath the skin can sometimes resemble keloid scars. Cysts generally present very differently – you can move the skin over the cyst wall itself, and they may have a visible punctum.

Malignant considerations

There’s a rare but important entity called dermatofibrosarcoma protuberans (DFSP), an aggressive sarcoma that can look scar-like. While very rare, this should be kept in mind when the history is unclear or the presentation is atypical.

If a patient reports rapid growth, tenderness to touch, or if the growth appears asymmetrical – more nodular on one end and plaque-like on another – these are clinical clues that may suggest something other than a straightforward keloid scar. In such cases, taking a small biopsy is reasonable, as there shouldn’t be much sampling error for diagnosing malignant entities.

Prevention strategies during surger

Reducing tension in the wound, and reducing the risk of infection can help minimise the likelihood of keloids forming.

Pre-operative considerations

Prior to surgery, consider the preoperative risk factors: personal and family history, and the anatomical site of operation. Be upfront with high-risk patients about the possibility of keloid formation, while emphasising that for skin cancer removal, the benefits generally outweigh the risks.

Surgical techniques to reduce the risk of keloid scarring

Reducing infection risk

Infected wounds can lead to poor wound healing and subsequently raised or keloid scarring.

To reduce this risk, ensure very clean aseptic technique, and don’t tie epidermal sutures too tightly, as they can cut into the wound and cause infections.

Reducing tension in the wound

Scars fundamentally exist to reinforce wounds, and if a wound is perceived as weak, the skin sends molecular signals to strengthen it by developing thickened collagen and fibrosis.

‘Undermining’ technique

This involves separating the dermis from the subcutaneous fat so the skin slides over with less tension placed on the wound edge. The tension is distributed through the entire region rather than concentrated at the wound edges.

Use absorbable dermal sutures underneath

This helps reduce surface tension. Some dermatologists avoid epidermal sutures entirely, hiding all sutures underneath the skin to reduce the risk of developing fishbone or herringbone scarring patterns.

Managing high-movement areas

When operating across joints or areas of movement, advise patients not to hyperflex or hyperextend the affected joint. However, as the practitioner, you should be operating such that tissue slides over subcutaneous surfaces regardless of patient movement.

For larger surgeries, consider whether brief hospitalisation and rehabilitation might be beneficial to ensure no additional wound tension occurs at the surgical site.

Postoperative care strategies

Proper postoperative management is crucial for optimal scar outcomes.

Suture removal timing

Remove sutures at appropriate intervals: seven to maximum 10 days for head and neck procedures, and 14 to 16 days for trunk and limb surgeries.

Scar management techniques

After suture removal, patients can begin massaging the area. While there are many fancy scar therapy gels available, the evidence can be weak for some of these products. However, there’s good evidence for silicon use – whether as silicon sheeting or gel applied over the scar – which provides an environment that reduces raised scars and promotes better healing.

Massage is probably the most recommended technique for ongoing scar management.

Follow-up planning

Ensure the wound doesn’t become infected and book a follow-up appointment in approximately three months. This gives you an opportunity to review the scar and treat it if the patient wishes to proceed with intervention.

Practice tip: There’s a common misconception that old scars can’t be treated, but keloid scars that are more than six to 12 months old can be successfully managed.

Treating keloid scars

Treatment is particularly beneficial when keloids cause symptoms. The two most common symptoms patients experience are pain (particularly on palpation) and itch. Provided you’ve made the correct diagnosis, treating symptomatic keloids can be very satisfying for both patient and practitioner.

Intralesional steroid therapy

Intralesional steroids remain the mainstay of keloid treatment. The key is developing experience with these injections, particularly understanding the appropriate strength of product to use.

Dosing considerations: Triamcinolone A10 is the standard concentration, but triamcinolone A40 (four times the concentration) is available for more challenging cases. For older or larger scars, it’s reasonable to inject up to one millilitre of triamcinolone A40.

You can always dilute the A40 in equal parts saline solution to reduce the concentration by half. If the scar continues to improve, you can step down to the lower standard concentration of triamcinolone A10.

Practical injection techniques

Equipment selection: Use an insulin syringe for two key reasons: it holds exactly one millilitre, and it’s effectively luer-locked so the needle won’t detach under pressure and spray triamcinolone over you and the patient.

Needle choice: A 25-gauge needle is generally sufficient, but it comes down to personal preference.

Injection approach: Whether you approach vertically or from the side doesn’t matter significantly. For large scars, you may need to approach from multiple angles.

Depth precision: This is crucial – inject just the scar itself, not underneath it, as triamcinolone can cause fat atrophy and subsequent depressions. Inject until the scar blanches.

Volume limits: Don’t exceed the equivalent of one millilitre of triamcinolone A40 per session. If diluting to A10 strength, this equates to four millilitres total volume.

Softening difficult scars

The first injection is often very difficult because the scar is firm. You can reduce this difficulty by using liquid nitrogen cryotherapy prior to injection. Freezing the keloid scar creates an oedematous response that softens the scar, making injection easier. Subsequent injections are typically less difficult as the scar has already begun to soften.

Treatment intervals

Allow four to six weeks between injection sessions to give adequate time for response and healing.

Advanced treatment options

For scars not responding well to standard intralesional steroids, several options exist.

Combination therapy

5-fluorouracil can be mixed with steroids in equal parts, though this requires appropriate disposal strategies and safety requirements as it’s a chemotherapy agent. Take particular care to avoid contact with eyes.

Surgical intervention

Consider excising the scar and injecting the subsequent closure with intralesional steroid. For ear keloids, which often present as dumbbell-shaped scars in front of and behind the ear, excision can be very effective once the keloid has been reduced with injections. Cut through the ear and suture the tissue both in front of and behind the ear, then inject intralesional steroid at the time of suture removal to prevent reformation.

Radiotherapy

For severe cases, radiotherapy may be considered as part of a coordinated treatment approach involving intralesional steroids, surgical treatment, and subsequent radiotherapy.

When and where to refer

There’s no perfect answer for referral timing, but dermatologists understand all the different treatment modalities and their appropriate applications. Most dermatologists and experienced GPs are comfortable treating keloid scars.

For small areas, many practitioners feel comfortable with excision. Consider referral to plastic surgeons or radiation oncologists when dealing with large areas where intralesional injections would involve too many sites to be practical.

Remember that these specialists often work collaboratively – plastic surgeons may refer to radiation oncologists and vice versa, depending on the specific case requirements.

Key takeaways

• Once you’ve arrived at a keloid diagnosis, discuss intralesional steroid injections with the patient and consider gaining experience by treating these rewarding conditions
• Reduce wound tension during surgery through proper technique, undermining, and appropriate suture placement to minimise keloid formation signals
• Large or complex keloid scars often require a multidisciplinary approach involving dermatologists, plastic surgeons, and radiation oncologists working together
• Use practical injection techniques: insulin syringes, 25-gauge needles, precise depth control, and consider cryotherapy pre-treatment for difficult scars
• Allow 4-6 weeks between injection sessions and don’t exceed one millilitre of triamcinolone A40 equivalent per treatment session.

Dr Philip Tong is a Sydney-based dermatologist and Founder of DermScreen, a telehealth platform that supports GPs with dermatology-related clinical decision making. He offers nation-wide telehealth services for medical dermatology including acne, eczema and psoriasis through his clinic Dermatology Junction.