['Lichen planus (LP) is a classic skin disease that can involve the skin, hair, and nails, as well as the oral and genital mucosa. Histopathology is characterized by a T-lymphocytic, lichenoid, and interface dermatitis. Multiple case reports and small case series have shown that LP can involve the esophagus. However, the diagnostic criteria, incidence, and best treatment options remain uncertain. This study aimed to refine the diagnostic criteria, estimate prevalence, and present an outlook on treatment options to prevent long-term sequelae.', 'Thirty-two consecutive patients with LP of the skin, hair, nails, oral mucosa, and/or genital mucosa underwent a comprehensive clinicopathologic assessment. Esophagogastroduodenoscopy was performed, and biopsies were evaluated histologically, immunohistochemically, and by direct immunofluorescence. Patients diagnosed with esophageal lichen planus (ELP) were followed up prospectively where possible.', 'In total, 20 of 32 patients had ELP. Ten of these 20 patients were classified as having proven ELP, with clear-cut endoscopically visible lesions; the other 10 were classified as having probable ELP. Eight of 10 patients with proven ELP were started on new or additional therapy because of esophageal findings. Treatment with a topical budesonide formulation or systemic corticosteroids was successful in most patients with proven ELP and reversed functional esophageal stenosis.'] Is esophageal involvement frequent in lichen planus : study in 32 patients with suggestion of clinicopathologic diagnostic criteria and therapeutic implications?