Lichen planus pigmentosus (LPP) is a rare form of lichen planus. It is characterized by oval or irregularly-shaped brown to gray-brown macules and patches on the skin. Areas that are exposed to sun such as the forehead, temples and neck are most commonly affected. However, the macules and patches may also develop on the trunk or in places where two areas of skin touch or rub together (i.e. the armpit, groin, etc). LPP is a chronic, relapsing condition with periods of worsening symptoms separated by periods of remission (decreasing or disappearing symptoms). The cause of LPP is unknown, but studies suggest it may be triggered by UV light, viral infections, or agents applied to the skin such as mustard oil and amla oil. Treatment for LPP depends on the symptoms in each person.

Although there usually are not other symptoms, some people may experience mild itching and/or burning, or develop other features of lichen planus. Please click here to learn more about the signs and symptoms that may be found in lichen planus.

LPP usually affects young to middle-aged adults who have dark skin, especially those of Indian, Latin American, or Middle Eastern descent.

The underlying cause of lichen planus pigmentosus is currently unknown. However, studies suggest that the condition may be triggered by viral infections, UV light or the application of certain oils to the hair or skin (i.e. mustard oil, amla oil, or henna hair dyes).

A diagnosis of lichen planus pigmentosus is usually suspected based on the presence of characteristic signs and symptoms. A skin biopsy may then be ordered to confirm the diagnosis.

No treatment options have shown consistent responses, and evidence of successful treatment has been limited to a few case series. Treatment options may include:

• Vitamin A
• Topical corticosteroids
• Topical calcineurin inhibitors such as tacrolimus (medications that are typically used to treat eczema)
• Dapsone (a medication used to treat leprosy and skin infections)
• Skin lightening agents
• Laser therapy

In some cases, LPP goes away on its own within weeks. In other cases, pigmentation persists for years.

The long-term outlook (prognosis) for people with lichen planus pigmentosus (LPP) is generally good. Aside from the characteristic macules and patches on the skin, many people do not have any other symptoms. In those who do experience itching and/or burning of the skin or other features of lichen planus, symptoms usually improve with treatment. Unfortunately, LPP is generally a chronic, relapsing condition with periods of exacerbations (worsening symptoms) separated by periods of remission (a decrease in or disappearance of symptoms).