What Is a Keloid Scar? - Definition, Causes & Removal

Instructor: Rachel Torrens

Rachel is a Nurse Practitioner with experience working as a high school teacher, skin surgery center, and as a family NP.

What happens when the body's own injury repair system just doesn't know when to stop repairing? A keloid forms! Learn more about this fascinating phenomenon with this lesson.

What Is a Keloid Scar?

Have you ever baked a cake? You follow the recipe, and an hour later pull out a gloriously golden yellow cake. You whip up the frosting and wait impatiently for the cake to cool. Finally, you get the icing on your spatula and drag it across the top of the cake, only to have the top layer of cake come with it! Then you have cake bits in your frosting, and your cake is uneven. In desperation, you get more icing and glob it on the ruined area, only to pull up more cake. And so on and so on, until you have an unsightly mound of icing on one part of your cake. But somehow, you can't stop yourself from adding more icing in an attempt to hide the blunder. Well, keloids are similar in that they just can't stop themselves!

Definition of a Keloid

Our bodies are amazingly equipped to handle injuries to the skin. As soon as the outer layer of your skin is damaged, several complicated responses begin. Injured skin cells release chemicals, which alert other cells in the body that they need help. White blood cells, platelets, and other cells respond to this 'S-O-S' signal, rushing to the area to repair the damage with fibrous tissue. However, with a keloid, just like you with your cake debacle, the fibrous tissue keeps repairing and repairing. It doesn't know when to call it quits!

Keloid formation following an ear piercing.
Keloid formation following an ear piercing.

This results in a keloid scar or a bulging scar that extends beyond the original wound site. The keloid usually has a shiny appearance, and is pink or red, but will darken if exposed to sunlight.

Causes of a Keloid

One of the most frustrating aspects of keloids is that scientists still don't know exactly why the fibrous tissue doesn't get the STOP message. What they do know is that any injury to the skin can result in keloid formation. The most common causes cited are acne, body piercings, burns, scratches, surgical incisions, chickenpox, and vaccination sites. In addition, scientists believe that there is a genetic component to keloids. So if your parents have a history of over reactive scars, the likelihood of you developing one is greater. Keloids have the same occurrence rate regardless of gender, but a higher incidence is noted in people of darker skin colors.

Treatments for a Keloid

It is important to note that keloid removal is considered cosmetic in most cases and not medically necessary. However, keloids can be itchy and tender. Also the excessive scar tissue can limit mobility depending on the affected body area. Keloids can become smaller and smoother over time, but this is the exception rather than the rule. Most require treatment in order to resolve.

Keloid formation after surgical incision.
Keloid formation after surgical incision.

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