We all get the occasional cut or scrape. You may burn your fingers or arm when cooking dinner or get a bug bite during the summertime. For most of us, these are simply a nuisance - even if painful for a few minutes or days - we know it will go away and our skin will heal. But for those with psoriasis, these skin irritations can be a trigger for a new psoriasis site or flare up.
The Koebner Phenomenon
The Koebner phenomenon is when psoriasis plaques form at the site of a skin injury. It is named after Dr. Heinrich Koebner, who noticed this phenomenon in the 19th century. Any skin injury that damages the dermis, which is the layer of skin below the surface, can cause psoriasis plaques to form. According to the National Psoriasis Foundation, about one-half of individuals with psoriasis experience the Boebner phenomenon at some time and some develop a new lesion every time the skin is injured.
Causes of the Koebner Phenomenon
Scrapes and cuts that do not penetrate below the top layer of the skin do not cause additional lesions to appear. However, if the skin irritation damages the dermis, the layer directly below the top layer of skin, you can develop new lesions. Any type of skin injury can cause this including;
- Burns (including chemical burns and sunburns)
- Bug bites
- Irritation caused by clothing rubbing against your skin
- Poison ivy/poison oak
- Chicken pox or other rashes
- Accupuncture needles
- Tattoo needles
Normally, a new lesion will appear anywhere between 3 days after the injury up to 2 weeks. You may be more at risk of developing new lesions if you are have active psoriasis lesions at the time you get the skin irritation.
Tips for Preventing Skin Injuries
For those with psoriasis, extra precautions need to be taken to do even routine chores and activities. Keeping your skin protected will help you avoid skin injuries. The following are some tips:
- Wear long sleeves and gloves when doing household chores, hiking and gardening, especially if you are pruning plants and bushes or working with chemicals.
- Make sure to always use bug-spray and keep skin covered with long sleeves when outdoors.
- Use warm water for showers and baths and never scrub your skin, instead use a soft wash cloth and pat your skin dry when done.
- Use moisturizers to avoid having dry, itchy skin you are tempted to scratch.
- Keep your nails cut and trimmed so you can’t accidently cut yourself if you do scratch your skin.
- Always use sun protection when going outdoors to prevent sunburn
- Keep clothing soft. Use cotton fabrics that don’t irritate your skin
- Use an electric razor rather than one with blades
If you do get an injury, no matter how slight, make sure to treat it immediately. Wash gently with warm water and a gentle soap. Treating the injury immediately will cut down the chances of it becoming infected. Once a cut does become infected, the chances of developing psoriasis lesions increases.
"Frequently Asked Questions About Psoriasis," Date Unknown, Staff Writer, American Academy of Dermatology
"Koebner Phenomenon," Date Unknown, Staff Writer, National Psoriasis Foundation
"The Koebner Phenomenon," 2011, March/April, L. Sagi and H. Trau, Clinical Dermatology, pp. 231-236