Lichen Planus

Abstract

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

A Rare Case Report: Five Variants of Lichen Planus in a Young Male Patient

“…Annular lichen planus does not cause as much pruritus as other subtypes, and patients are often asymptomatic. It typically involves the axilla, groin, extremities, and male genitalia [ 7 ]. Finally, lichen planus pigmentosus is one of the rarer subtypes that is mostly seen in sun-exposed or flexural areas.…”

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

“…Involvement of the scalp is also more often reported in female patients, with a sex ratio close to 5:1. Clinically, we recognize three major subtypes of LP: cutaneous LP (CLP), MLP, and LP of the scalp, classically called lichen planopilaris (LPP) ( 14 , 106 , 107 ). CLP is classically characterized by violaceous, polygonal, slightly scaling and extremely pruriginous flat papules, which affect mostly the extremities ( Figures 1E,F ).…”

“…At times, LP may pose a therapeutic challenge. Indeed, some clinical variants are characterized by a refractory course, especially LPP, ulcerative oral LP and genital LP ( 14 , 109 ). In CLP topical steroid treatments usually in combination with UVB or PUVA phototherapy are recommended.…”

“…In addition, a phase II study to evaluate the efficacy, safety, and tolerability of secukinumab 300 mg over 32 weeks in adult patients with biopsy-proven clinical variants of LP is ongoing (EudraCT number 2019-003588-24). Furthermore, JAKi have emerged as promising therapeutic agents in LP ( 14 , 117 ).…”

Increased Level of Serum Wingless-Type Mouse Mammary Tumor Virus Integration Site Family Member 5a in Patients with Cutaneous Lichen Planus

“…Environmental factors, such as infections (hepatitis C virus infection, Epstein-Barr virus), allergies, drugs, stress/anxiety and internal malignancies are also contribute to the development of LP. 4 It is well known that T cell regulated immune response is the core of LP pathogenesis, both CD4 + and CD8 + in the center and mediated immune responses against keratinocytes. 5 The perforin/granzyme pathway or the Fas/FasL ligand system seems to be involved in the main pathways of cytotoxicity mediated by CD4 + and CD8 + T cells.…”