Lichen planus

<p>Lichen planus is an inflammatory condition that causes an itchy rash on the skin or in the mouth. Other symptoms include dry mouth, metallic taste, hair loss, and nail abnormalities. While the exact cause is unknown, it is likely to be related to an allergic or immune reaction that induces keratinocyte apoptosis. It is most common in middle-aged adults aged 30 to 60 years. The alteration of cytokine expression linked with hepatitis C may increase susceptibility. Other risk factors include exposure to medications, dyes, and other chemical substances. Diagnosis may be based on clinical appearance and confirmed by lesion biopsy. Blood tests to rule out hepatitis may also be appropriate. Treatment with topical and/or systemic corticosteroids, retinoids, calcineurin inhibitors, immunosuppressants and phototherapy may be necessary to achieve disease control.