Lichen planus (LP) is a common, chronic inflammatory skin disease. P56 is an interferon inducible protein that is produced in response to viral infection. Helicobacter pylori is a Gram-negative spiral-shaped microaerophillic bacteria. An increasing number of dermatologic diseases have been related to H. Pylori infection. This study was done on 34 patients and 34 control subjects. A biopsy and blood sample was taken from all subjects to measure anti H. pylori antibodies and p56. There was no significant difference in colonization of H. pylori between patients and controls. P56 and Ig G were significantly higher in patients than controls.