What is lichen planus?

What is lichen planus?

Lichen planus is a chronic, itchy rash that can appear in just one area of the body or affect several parts of the body at the same time. Most commonly, it is seen on the skin of the arms and legs and inside the mouth. Lichen planus can also affect the nails and the skin in the genital area.

What are the symptoms of lichen planus?

  • On the skin, lichen planus causes itchy groups of bumps that are shiny, firm and slightly purple.
  • Lichen planus in the mouth may be painful and look like a white lacy rash.
  • Lichen planus of the nails causes distortion including ridges and grooves.

Variants of the disease may include lesions that look like blisters and ulcers, and those that look similar but are induced by a medication-adverse reaction. Lichen planus of the scalp, or lichen planopilaris, may be itchy or painful and cause alopecia (hair loss).

What causes lichen planus?

The cause is not completely clear but is likely a combination of an autoimmune reaction and environmental triggers.

Environmental factors include viruses (particularly hepatitis C), medications and allergic reactions to a foreign substance including metallic dental materials. It is important to tell your doctor about all the medications you were taking when you first noticed the rash.