Lichen Planus

Chronic inflammatory skin diseases constitute a heterogeneous group of pathologies. They affect the skin but also other organs (joints, lungs, muscles, etc.). Their prognosis and response to treatments is extremely variable. The discovery of prognosis factors will help to precisely guide the treatment regimen and its intensification based on individual markers. The identification of new therapeutic targets is essential to develop new innovative treatments for inflammatory skin diseases. The main objective is to identify new cellular or molecular prognostic factors associated with treatment response at 1 year in inflammatory skin diseases. The secondary objectives are a better understanding of the pathophysiology of chronic inflammatory skin diseases, the identification of new cellular, molecular and microbiological prognostic factors associated with the clinical state after 10 years of evolution and the identification of prognostic markers of drug toxicity.

Although it is well known that the clinical expression and course of chronic inflammatory skin diseases are highly variable, there are insufficient epidemiological data on this, and the factors that determine the manifestation, clinical features and course are also largely unknown. There are currently no reliable markers that could predict or delineate patient subgroups to support patient management. The aim of this project is to identify clinical and molecular factors that correlate with disease, disease subtypes and progression through in-depth long-term clinical characterization of patients with chronic inflammatory skin diseases and examination of individual biomaterials.

Lichen planus (LP) is a chronic inflammatory disease of unknown aetiology, affecting the skin and mucous membranes, characterised by a CD8+ cytotoxic T-cell infiltrate, associated with epithelial cell death and disruption of the basement membrane zone. In previous work, T cell antigen receptor (TCR) repertoire studies were performed. In all patients tested, whether with erosive or non-erosive LP, unique nucleotide sequences, called clonotypes, have been identified. They appear during the process of TCR gene rearrangement. These clonotypes are specific for human papillomavirus (HPV) in blood and lesions, suggesting antigenic stimulation of these clonotypes by a viral epitope of HPV, which crosses with an epitope on keratinocytes. The diagnosis of LP is made on the basis of clinical and histological criteria, but in some patients and in some anatomical locations, the diagnosis is difficult to make and LP may be confused with other skin conditions.

Lichen planus is a chronic inflammatory skin condition with unknown etiology. It requires a long term treatment. Evaulating the most efficacious, safe and affordable treatment option is the need of the hour. This study is going to compare the efficacy of two familiar drugs (acitretin and methotrexate) in the treatment of generalized lichen planus as to find out the relatively more effective and safer treatment.