Keloids vs. Hypertrophic Scars: Understanding the Differences

Understanding Keloids and Hypertrophic Scars: A Comprehensive Guide for Indian Readers

Scars are a natural part of the healing process after an injury to the skin. While most scars fade over time, some can become more prominent, leading to conditions like hypertrophic scars and keloids. Both are raised scars that can cause cosmetic concerns and sometimes discomfort. However, they are distinct conditions with different characteristics, causes, and treatment approaches. This guide aims to clarify the differences between keloids and hypertrophic scars, providing practical information for readers in India.

What are Scars?

When your skin is injured, whether from a cut, burn, surgery, or acne, your body initiates a repair process. This process involves producing collagen, a protein that helps to mend the damaged tissue. In most cases, the scar that forms is flat, pale, and barely noticeable once healed. However, in some individuals, the healing process can go into overdrive, leading to the formation of excess scar tissue.

Hypertrophic Scars Explained

A hypertrophic scar is a raised, red scar that forms within the boundaries of the original wound. It occurs when the body produces too much collagen during the healing phase, causing the scar tissue to become thicker and more prominent than the surrounding skin. These scars typically appear a few weeks after the injury and may continue to grow for a few months before stabilizing. They are more common in areas of the body where the skin is stretched or under tension.

Causes of Hypertrophic Scars:

• Deep burns
• Surgical incisions
• Accidental cuts and abrasions
• Acne or other inflammatory skin conditions
• Increased tension on the wound site
• Infection of the wound

Appearance of Hypertrophic Scars:

• Raised and firm to the touch
• Red or pink in colour
• Confined to the original wound area
• May be itchy or tender
• Can improve over time, sometimes with treatment

Keloids: When Scars Grow Beyond Boundaries

Keloids are also raised scars, but they have a key difference: they grow beyond the original boundaries of the wound. Keloids are essentially an overgrowth of scar tissue that extends onto the surrounding healthy skin. They can appear months or even years after the initial injury and can continue to grow over time. Doctors often consider keloids to be benign tumours of the skin, meaning they are not cancerous but represent an abnormal proliferation of tissue.

Causes of Keloids:

• Minor skin injuries (e.g., insect bites, acne, piercings)
• Major injuries (e.g., burns, surgery)
• Genetics: A family history of keloids increases the risk.
• Skin type: People with darker skin tones are more prone to developing keloids.
• Age: Keloids are more common in individuals between the ages of 10 and 30.

Appearance of Keloids:

• Raised, often with a rubbery or firm texture
• Can be flesh-coloured, pink, red, or darker than the surrounding skin
• Extend beyond the original wound margins
• Can be itchy, tender, or painful
• May continue to grow over time
• Can occur spontaneously without any apparent injury

Key Differences Between Keloids and Hypertrophic Scars

While both are raised scars resulting from excessive collagen production, their behaviour and characteristics differ significantly:

1. Growth Pattern: Hypertrophic scars stay within the confines of the original wound, whereas keloids grow beyond these boundaries.
2. Onset: Hypertrophic scars usually appear soon after wound healing, while keloids can take months or even years to develop.
3. Resolution: Hypertrophic scars often improve and flatten over time, sometimes with treatment. Keloids are more persistent and can continue to grow, making them harder to treat.
4. Collagen Structure: In hypertrophic scars, collagen fibres are arranged in a more organized, parallel pattern. In keloids, the collagen fibres are arranged randomly.
5. Prevalence: Hypertrophic scars are more common than keloids. Up to 10% of people may develop keloids.

Keloids and Hypertrophic Scars on Skin of Colour

It's important to note that individuals with darker skin tones are more susceptible to developing keloids. Research suggests that on darker skin, keloids might develop faster, appear more frequently, and can be more widespread than on lighter skin. This is an important consideration for diagnosis and treatment in the diverse population of India.

Can a Hypertrophic Scar Turn into a Keloid?

No, a hypertrophic scar will not transform into a keloid. They are distinct conditions that arise from different healing responses, even though they share some similarities.

Diagnosis

Diagnosing between a keloid and a hypertrophic scar is typically done by a dermatologist or healthcare professional based on a visual examination of the scar and its history. They will consider:

• The location and size of the scar
• Whether the scar extends beyond the original wound
• The time of onset after the injury
• The patient's medical history, including any family history of keloids

In some cases, a biopsy might be performed to examine the tissue structure, especially if there is any uncertainty.

Treatment Options

Treatment for both conditions aims to flatten the scar, reduce itching and pain, and improve appearance. However, treatment approaches may differ due to the nature of the scar.

Treatments for Hypertrophic Scars:

• Silicone sheets or gels: Applied directly to the scar.
• Corticosteroid injections: To reduce inflammation and flatten the scar.
• Pressure therapy: Wearing compression garments over the scar.
• Laser therapy: To improve the colour and texture of the scar.
• Cryotherapy: Freezing the scar tissue.
• Surgical removal: In some cases, though recurrence is possible.

Treatments for Keloids:

Keloids are generally more challenging to treat, and recurrence after removal is common. Treatment options include:

• Corticosteroid injections: Often the first line of treatment to reduce inflammation and flatten the keloid.
• Silicone sheeting or gels: Can help to soften and flatten the scar.
• Pressure therapy: Especially after surgery or injury, to prevent keloid formation or growth.
• Cryotherapy: Freezing the keloid tissue.
• Laser therapy: To improve the appearance and reduce redness.
• Surgical removal: Often combined with other treatments like steroid injections or radiation therapy to minimize recurrence.
• Radiation therapy: Used in some cases after surgery to prevent regrowth.
• Topical treatments: Such as silicone-based creams and onion extract gels.

Prevention

While not all scars can be prevented, certain measures can reduce the risk of developing hypertrophic scars and keloids:

• Proper wound care: Keep wounds clean and moisturised.
• Avoid unnecessary cosmetic procedures: Especially if you have a history of keloids.
• Be cautious with piercings: Especially in areas prone to keloids, like the earlobes.
• Sun protection: Protect scars from sun exposure, as UV rays can make them darker and more noticeable.
• Consider preventative treatments: If you are undergoing surgery and have a history of keloids, discuss preventative measures with your doctor.
• Proper suturing techniques: Ensure your doctor uses the correct technique when closing wounds, with needles entering the skin at a 90-degree angle to create a loop.

When to Consult a Doctor

It is advisable to consult a dermatologist or healthcare professional if:

• A scar is excessively raised, red, or itchy.
• A scar is growing beyond the original wound area.
• A scar is causing pain or discomfort.
• You have a family history of keloids and sustain a skin injury.
• You are concerned about the appearance of any scar.

Frequently Asked Questions (FAQ)

Understanding the distinction between keloids and hypertrophic scars is crucial for appropriate management and treatment. If you have concerns about a scar, always seek professional medical advice from a qualified dermatologist.