Lichen planus and lichenoid reactions as a systemic disease

Mucosal erosive lichen planus is associated with hepatitis C virus: analysis of 104 patients with lichen planus in two decades

“…The frequencies of LP and LP association with HCV infection depend on the prevalence of HCV diagnosis in each country, and the oral mucosal form of LP has been emphasized . In our study, 9.62% of the patients diagnosed with LP had positive anti‐HCV serology.…”

“…Lichen planus (LP) affects the skin and mucous membranes, with incidence in 0.9–1.2% of the world's population . The etiology of LP remains unknown, but it has been associated with viral infections, including hepatitis C virus (HCV), which has been associated with LP since 1991 .…”

Association of classic lichen planus with human herpesvirus-7 infection

“…Lichen planus is a chronic inflammatory papulosquamous skin disease that may involve skin, mucous membranes, scalp, and nails. The disease affects 0.9–1.2% of the population . It often occurs between 30 and 60 years of age and is uncommon in children .…”

“…Flat‐topped, polyhedral purple‐colored itchy papular rashes are classic skin lesions of this disease, which commonly occur on extremities, particularly ankle and volar surface of the wrist. Generalized lesions are sometimes observed on the trunk …”

“…Clinical data indicate a relationship between exposure to a number of exogenous factors (e.g., viruses, medications, and contact allergens) with progressive lichen planus. Presentation of these exogenous antigens by antigen‐presenting cells is an important element in production of cytotoxic T cells …”