Keloid vs Hypertrophic Scars: When to Excise, Inject, or Revise the Scar

Keloid vs Hypertrophic Scars: When Surgery Helps (and When It Doesn’t)

At Oregon Cosmetic and Reconstructive Clinic, I meet patients who feel frustrated by raised scars. These scars can feel firm, itchy, or even painful. Just as importantly, they can draw attention in ways that patients don’t want.

So let’s break this down in a simple way. Not all raised scars are the same—and understanding the difference helps us choose the right treatment.

What Is the Difference Between a Keloid and a Hypertrophic Scar?

Although both scars look raised, they behave very differently.

Hypertrophic Scars

• Stay within the original wound boundaries
• Often appear red, thick, and slightly raised
• May improve slowly over time
• Respond well to non-surgical treatments

Keloid Scars

• Grow beyond the original injury
• Can become large, firm, and irregular
• Often continue to grow over time
• Have a higher risk of coming back after treatment

👉 In short: hypertrophic scars stay contained, while keloids “spill over.”

When Do I Recommend Injection Instead of Surgery?

Before jumping to surgery, I almost always start with simpler treatments.

Steroid Injections

Steroid injections help flatten and soften scars by reducing inflammation and collagen buildup.

I often recommend injections when:

• The scar is still early or actively growing
• The scar is not causing tightness or distortion
• We want to avoid creating a new incision

These injections are quick and can be repeated over time.

When Does Surgical Excision Make Sense?

Sometimes, injections alone are not enough. That’s when I consider surgical excision.

I recommend excision when:

• The scar is large or bulky
• The scar causes tightness or restricts movement
• The scar sits in a highly visible area
• Prior treatments (like injections) did not work

During surgery, I remove the scar tissue and carefully close the area to create a thinner, more controlled scar.

However, this is important:
👉 Surgery alone is not enough—especially for keloids.

Without prevention, the scar can come back.

Why Do We Sometimes Change the Direction of a Scar? (Z-Plasty)

Not all scars should stay in their original direction.

Sometimes, I perform a technique called Z-plasty.

What Z-plasty does:

• Reorients the scar to follow natural skin lines
• Releases tension on the skin
• Improves movement, especially near joints
• Helps the scar look less noticeable

Instead of a straight line, the scar becomes a zig-zag pattern, which blends more naturally with the skin.

How We Help Prevent Recurrence After Surgery

This is one of the most important parts of treatment. After surgery, I focus on guiding how the scar heals—not just removing it.

Silicone Sheeting

Silicone sheets help:

• Hydrate the scar
• Reduce thickness
• Improve color over time

👉 Learn more about scar care here:
Scar Treatment: Massage and Silicone Sheeting

Steroid Injections (After Surgery)

Even after excision, I often continue steroid injections to:

• Keep the scar flat
• Reduce inflammation early
• Lower recurrence risk

CO₂ Laser Treatment

In addition to injections and silicone, I often use CO₂ laser resurfacing to improve scar quality.

How CO₂ laser helps:

• Softens thick scars by remodeling collagen
• Improves texture and color
• Helps scars become flatter and more flexible

CO₂ laser works well for hypertrophic and depressed scars. I can also combine it with other treatments for better results.

Radiation Therapy (For Keloids)

For true keloids, I sometimes recommend low-dose radiation therapy after surgery.

Why this helps:

• Targets the cells that cause excess scar growth
• Significantly lowers the chance of recurrence
• Works best when done soon after excision

This is not needed for most hypertrophic scars—but it can be very helpful for keloids.

Putting It All Together

When I treat scars, I don’t rely on just one method. Instead, I combine treatments to get the best result.

Simple approach:

• Start with injections and silicone
• Move to surgical excision if needed
• Add Z-plasty when tension or direction matters
• Use prevention strategies to stop recurrence

Each scar behaves differently. So, I tailor the plan to match your skin, your scar, and your goals.

When Should You Get a Scar Evaluated?

You may benefit from an evaluation if your scar:

• Continues to grow over time
• Feels tight, itchy, or painful
• Stands out in a way that bothers you
• Limits movement or function

Learn more about CO2 laser treatment with Dr. Jenq or schedule a scar evaluation.

Frequently asked questions

What is the difference between a keloid and a hypertrophic scar?

Hypertrophic scars stay within the original wound boundaries and may improve slowly over time. Keloids grow beyond the original injury, often continue to grow and have a higher risk of coming back after treatment.

When is surgery recommended for a raised scar?

Dr. Jenq recommends excision when the scar is large or bulky, causes tightness or restricts movement, sits in a highly visible area, or did not respond to treatments like injections.

Can a keloid come back after it is removed?

Yes. Surgery alone is not enough, especially for keloids, so prevention such as silicone sheeting, steroid injections and sometimes low-dose radiation is used after excision.

What is Z-plasty for scars?

Z-plasty reorients a scar to follow natural skin lines, releases tension and improves movement. The scar becomes a zig-zag pattern that blends more naturally with the skin.