What is lichen planus (LP)?
What causes lichen planus?
Lichen planus may be triggered by or found in association with outside factors, such as medications or a contact allergy. Nearly 40% of patients with oral lichen planus may have a contact hypersensitivity to metallic dental prosthetics (containing mercury, copper, or gold).
The pathogenesis of lichen planus is poorly understood. It may be incited by trauma, infection (such as hepatitis C), and may have a genetic component.
Who is at risk for lichen planus?
What are the signs/symptoms of lichen planus?
Classically lichen planus will appear as a violet to purple, flat-topped polygonal small bumps often with a white-to-lavender overlying scale. This can occur in areas of prior trauma or injury. Presentation is almost always on both sides of the body and symmetric. Oral mucosa (inside of mouth) is commonly affected (15% of cases), and buccal mucosal (inside of cheeks) disease is present in 90% of cases of oral lichen planus. When oral involvement is present, patients may have discomfort, stinging, or pain due to hot foods and drinks. Lesions may be found less frequently around the anus and on the genitalia. When the palms and soles are affected, the lesions may be firm and rough with a yellowish hue.
Are there any complications of lichen planus?
Erosive (ulcer-like) forms of lichen planus, especially of the oral mucosa, genitalia, and rarely of the skin, may be complicated by the development of squamous cell carcinoma.
How is lichen planus diagnosed?
Lichen planus can be clinically diagnosed, but a biopsy is often performed to confirm the diagnosis.