Lichen planus is a disease that occurs within the mouth or on the skin, or may involve both sites. There are three types of lichen planus. The most common type is reticular lichen planus, discussed below. The second type is erosive lichen planus, a long-term and often very painful condition. These two types can often occur simultaneously within your mouth. The third type is hypertrophic lichen planus, which is less common and is characterized by thick, white, plaque-like areas within the mouth.

The oral lesions of reticular lichen planus are characterized by multiple white, pimple-like sores that multiply rapidly, then merge to form a linear, circular, or mesh-like pattern; a lacey-appearing network of lesions is common. Lichen planus lesions on the skin are purple, polygon-shaped, and itchy. This condition can be difficult for us to identify because of the many variations possible in the appearance of the lesions. The oral lesions may appear at any site within the mouth, but are most common on the tissue lining the inside of the cheeks (called the mucosa), the sides of the tongue, and the space between the lips and the cheeks (called the vestibule or sulcus). They occur most in those at or over middle age, and are very rare in children. The lesions, which don't present any symptoms other than tenderness, come and go at unpredictable intervals lasting for weeks or even months at a time.

Lichen planus lesions tend to flare up during stressful conditions. The precise cause is unknown, but it is believed that the condition occurs with higher incidence in those with diabetes, immune system deficiencies, or high blood pressure. It also has been shown to be more common in females.

The goal of treatment for lichen planus is to relieve the symptoms and speed healing of the lesions. We will examine a tissue sample under a

microscope (this is called a biopsy), and then carefully watch persistent lichen planus lesions, as they can be pre-cancerous.

* If the symptoms are mild, no treatment for the reticular type is necessary. In other types, where there is inflammation and discomfort:

* Antihistamines may provide you with some relief, especially from itching.

* A lidocaine mouthwash can numb the mouth and offers some relief from painful lesions.

*Topical vitamin A cream (retinoic acid) can reduce inflammation, and may speed healing of the lesions.

*We may use cortico steroids, either injected or applied topically, to reduce inflammation and suppress the uncomfortable symptoms.