Koebner Phenomenon

What is Koebner phenomenon?

Koebner phenomenon affects people with certain skin diseases, most often with psoriasis. Sometimes, it can happen to people with warts, vitiligo and lichen planus. An injury, wound or burn can cause new lesions that resemble the primary skin disease.

German physician Heinrich Koebner first described the phenomenon in 1876, now described as an isomorphic response. “Isomorphic” is Greek for equal shape. The new lesions look identical (or equal) to the original disease.

How common is Koebner phenomenon?

Koebner phenomenon is most common in people with psoriasis. It’s not as common in people with warts, vitiligo and lichen planus, though it still occurs. It also affects people with other skin diseases.

What causes Koebner phenomenon?

Experts aren’t sure why some people experience Koebner phenomenon. It tends to affect people with autoimmune diseases like psoriasis.

Who is at risk for Koebner phenomenon?

In addition to psoriasis, other skin diseases linked to Koebner phenomenon include:

• Warts.
• Vitiligo.
• Lichen planus.

What skin injuries cause Koebner phenomenon?

Any skin injury that penetrates your skin’s top layer (epidermis) and middle layer (dermis) may cause Koebner phenomenon, such as:

• Injections, piercings and punctures.
• Insect and animal bites.
• Scratching or self-injury (such as skin picking).
• Surgical procedures, wounds and injuries.
• Tattoos, including tattoo removal.
• Burns, including sunburns (less common).
• Radiation therapy (less common).

What are the symptoms of Koebner phenomenon?

Symptoms of Koebner phenomenon vary depending on your underlying skin disease and whether the disease is active (what’s known as a flare-up). New skin lesions may appear within 10 to 20 days of a skin injury.

The new skin lesions:

• Appear on previously healthy skin at the site of a skin injury.
• Resemble your underlying skin disease.
• Are usually linear (run in a straight line).

What are the complications of Koebner phenomenon?

Generally, there aren’t any complications associated with Koebner phenomenon.

How is Koebner phenomenon diagnosed?

A dermatologist evaluates and treats skin diseases like Koebner phenomenon. There isn’t a test for Koebner phenomenon. Your dermatologist makes the diagnosis based on appearance and history of prior skin diseases.

How is Koebner phenomenon treated?

There isn’t a specific treatment for Koebner phenomenon. As the phenomenon is simply an extension of your primary skin disease, treatment is usually the same.

Can you prevent Koebner phenomenon?

The best way to reduce your risk for Koebner phenomenon is to manage your primary disease. For example, if the phenomenon is due to psoriasis, find ways to manage your psoriasis symptoms. Additionally, you should minimize trauma to your skin whenever possible.

These steps may also help:

• Don’t pick or scratch your skin or nail cuticles.
• Protect your skin against sun damage.

What is the outlook for someone with Koebner phenomenon?

The outlook is generally good for people with Koebner phenomenon. The best thing you can do is treat any new lesions the same way you’d treat your primary skin disease. In addition, it’s important to follow your healthcare provider’s treatment recommendations. You should also take precautions to protect your skin from injuries.

When should I call my healthcare provider?

Call your healthcare provider if you experience:

• Disease flare-up.
• Severely itchy or painful skin.
• Signs of infection like oozing wounds or fever.

What should I ask my healthcare provider?

You may want to ask your healthcare provider:

• What caused Koebner phenomenon?
• What’s the best treatment for me?
• What steps can I take to prevent skin injuries and Koebner phenomenon?
• Should I look for signs of complications?

A note from Cleveland Clinic

If you have psoriasis, vitiligo or lichen planus and notice new skin lesions forming on an area of injured skin, you may have Koebner phenomenon. These lesions resemble your primary skin disease and may appear weeks after an injury. A healthcare provider like a dermatologist can make an accurate diagnosis. Proper disease management of conditions like psoriasis may lower your risk of Koebner phenomenon. Still, lesions can form even when you don’t have disease symptoms. It’s important to protect your skin from wounds, burns and other damage.