Lichen planus

Abstract

Key Features: Lichen planus (LP) is a chronic inflammatory skin disease mediated by skin-infiltrating T cells with autoaggressive potential. Viruses, drugs, and contact allergens constitute environmental factors that can trigger the onset of LP Memory T cells generated by a previously encountered virus could be cross-reactive with drugs, contact allergens, or alloantigens, and they are activated upon the recognition of these cross-reactive antigens to cause immu-nopathology. Treatment strategies of LP depend on avoidance of these environmental factors and modulation of the immune response so as to interfere with the function of skin-infiltrating T cells. The standard therapies for LP include topical and systemic corticosteroids, retinoids, antimicrobials and psoralen, and ultraviolet A. Oral ciclosporin and topical tacrolimus are safe and effective treatments for recalcitrant L P Although biologics such as alefacept and efalizumab offer interesting novel alternative treatments, a prospective study with long-term follow-up is needed to evaluate the efficacy and safety. © 2010 Springer-Verlag Berlin Heidelberg.