Keloid Causes, Symptoms, and Differentiation from Hypertrophic Scars/Acne | [Yonsei Star Dermatology Sinchon]

A keloid is a skin condition where a scar continues to grow beyond the original wound boundary after the wound has healed. The first question people usually have is, "How do I distinguish between a keloid and a common scar?" To put it simply, keloids are scars with a significant constitutional factor, and their progression is clearly different from hypertrophic scars or acne.

In the past, many people were unfamiliar with the term keloid itself or thought it didn't necessarily require treatment. Recently, however, the number of people visiting our clinic to address keloid scars has gradually increased. Today, we will select four frequently asked questions and address them step by step.

The exact reason why keloids form is not yet clearly understood. However, their mechanism can be inferred from the site of occurrence and the progression process. Keloid scars are reported to occur relatively often on the chest, shoulders, jaw, and abdomen.

These areas are characterized by increased fibroblast activity at the wound site or increased tension applied to that area. When tension increases, fibroblasts are believed to produce more collagen fibers than necessary, resulting in the scar swelling excessively.

Strength training, which increases tension and blood supply to the keloid area, is often cited as a factor that can worsen keloids. Therefore, it may be helpful to temporarily refrain from intense strength training in the affected area during treatment.

However, it is difficult to unconditionally advise those who enjoy exercise to stop. We recommend continuing exercise while also considering the following points:

• Reduce the intensity of movements that place direct tension on the keloid area.
• If you feel itching, pain, or a change in scar size during exercise, do not overexert yourself.
• If you are undergoing treatment, visit regularly to have your progress checked.
• Protect the area to prevent new, even small, injuries.

If you combine exercise with regular keloid treatment, it is safer to manage your condition. If you are concerned about scar progression, reviewing information on Keloid Scar Symptoms and Progression may help you understand. If you are curious about the progression, you can also use Inquire about keloid scars via chat consultation.

Keloid scars and hypertrophic scars may look similar, but they actually progress in completely different ways.

The biggest difference lies in the spread of the scar and whether it continues to progress.

Hypertrophic scars can occur in anyone after a severe injury, and the scar grows within the original wound boundary. In contrast, keloids only occur in individuals with a keloid predisposition, and they are characterized by excessive growth beyond the wound's edges and continuous progression.

Furthermore, most hypertrophic scars stabilize on their own over time, but keloid scars can continue to progress and gradually increase in size. Therefore, if a keloid is suspected, it is necessary to seek medical attention as soon as possible to slow its progression.

Occasionally, some people report that a keloid scar, which they never had before, suddenly appeared after a major trauma from surgery or an accident.

In such cases, it is not uncommon for individuals to be unaware of their keloid predisposition until a major trauma leads to the formation of a keloid.

Therefore, if you suspect you have a keloid predisposition, it is advisable to consult thoroughly with your doctor when deciding on surgical procedures, and to be as careful as possible to avoid even minor injuries in daily life.

Acne and keloid scars have relatively clear characteristics, making differentiation not difficult.

Acne is accompanied by inflammation, so it may feel warm or painful to the touch, and it has a soft, elastic feel.

On the other hand, keloids can sometimes result from excessive fibrosis of tissue due to inflammatory acne. In this case, the scar feels hard to the touch, but pain is not usually prominent. However, pain or itching may accompany the process of keloid enlargement.

Here are the distinguishing points you can check yourself:

• If it feels soft and painful to the touch, it is likely inflammatory acne.
• If it feels hard and grows beyond the boundary, suspect a keloid.
• If acne lesions persist in the same spot for more than 6 months, check for the possibility of a keloid.
• If the scar gradually enlarges or itching continues, confirm with a medical examination.

If an acne-like lesion persists in the same spot for a long time, it is necessary to distinguish whether it is acne or a scar. If you are concerned about scars left by acne, refer to the information on Acne Scar Types and Management. For hard, raised keloids, there is a method to control their progression with Triamcinolone Scar Injection. Depending on the shape or location of the scar, Surgical Scar Revision may also be considered.

If you are confused about whether you have a keloid, acne, or a hypertrophic scar, it is more accurate to have it directly confirmed in the clinic rather than self-diagnosing.

Today, we have looked at the causes and symptoms of keloids, as well as how to distinguish them from hypertrophic scars and acne. Since the type and extent of scar progression can vary from person to person, it is advisable to determine the appropriate direction for your scar through an accurate diagnosis.

If you are curious about your scar type, inquire via chat consultation

Dr. Sang-Joo Lee (Dermatologist) is the chief director of Yonsei Star Dermatology Sinchon, where he has long specialized in scar and pigment treatments. He will be the president of the Korean Dermatological Association in 2026 and is an adjunct professor at the Department of Dermatology, Yonsei University College of Medicine. View Chief Director Sang-Joo Lee's Profile First published 2024-08-05 / Last reviewed 2026년 7월 23일

This article is for general information purposes only, and the type of scar and treatment response may vary from individual to individual. Please consult a dermatologist for an accurate diagnosis and treatment plan.