pathogenesis

Last reviewed 04/2022

This is a condition of unknown aetiology, but lichen planus and lichenoid eruptions are thought to be an autoimmune disorder mediated by T-lymphocytes which attack keratinocytes found on the basal cell layer resulting in degeneration of the keratinocyte cells (1).

Several exogenous factors have been identified in the pathogenesis of some cases of lichen planus:

  • an association with hepatitis C (not hepatitis A or B)
  • contact allergens - gold and mercury amalgam (1)
  • lichen planus may be drug-induced - diuretics, antihypertensives, and hypoglycemic agents (2)

Reference:

  • 1. Dorothea C et al. Oral lichen planus. Arch Dermatol. 2007;143(4):511-515
  • 2. Hsu S, Feasel A.M. Photo Quiz : Koebner Streak. AAFP 2002; 65(3).