The symptoms of lichen planus vary depending on the areas affected. Typical signs and symptoms include:
- Purplish, flat-topped bumps, most often on the inner forearm, wrist or ankle, but sometimes on the external genitals
- Itching
- Blisters that may break to form scabs or crusts
- White spots or patches in the mouth — inside the cheeks or on the gums, lips or tongue
- Painful oral or vaginal ulcers
- Hair loss and scalp discoloration
- Nail damage or loss
The cause of lichen planus is unknown, though strong evidence suggests that inflammation, controlled by the immune system, gives rise to the lesions. However, certain diseases, medical conditions or other factors may act as triggers of lichen planus in some people. The possible triggers of lichen planus include:
- Hepatitis C infection
- Hepatitis B vaccine
- Flu vaccine
- Certain pigments, chemicals and metals
- Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, others)
- Certain medications for heart disease, high blood pressure or arthritis
Anyone can develop lichen planus, but the condition most often affects middle-aged adults.
Lichen planus can be difficult to manage on the vulva and in the vagina, causing severe pain and sometimes leaving scars. Sexual dysfunction can become a long-term complication. There is some evidence that lichen planus may increase your risk of a skin cancer known as squamous cell carcinoma, though the risk is small.
