The various clinical presentations and treatment options of Lichen Planus are reviewed in the latest article in our Clinical Practice series, including available data to guide management.
Lichen planus is a mucocutaneous inflammatory disease of unknown origin. The skin and oral mucosa are the most frequently involved areas. Other mucous membranes (including the genitalia, esophagus, and conjunctiva) and skin appendages (e.g., scalp hair and nails) can also be affected. One or several areas can be involved, either concomitantly or sequentially. The clinical presentation of lichen planus varies depending on the area involved.
• What is the typical presentation of lichen planus?
Cutaneous lichen planus is characterized by flat-topped, violaceous papules, which in some cases can be intensely itchy (the so-called “purple, polygonal, pruritic papules”). The lesions may result in long-standing residual hyperpigmentation, especially in dark-skinned patients. Oral lichen planus is characterized by symmetric reticular lesions that resemble a white, lacelike network, as well as by papules, plaques, erythematous lesions, and erosions; it is a chronic disease, and its erosive form is painful. The clinical characteristics of anogenital lichen planus are typically similar to those of both the cutaneous and the oral forms. The erosive form of mucosal lichen planus may result in fibrosis, with vulvar scarring, vaginal stenosis, phimosis, esophageal stricture, blindness, or obstruction of the lachrymal canal. Progressive scarring can also affect the nails and scalp.
• What other conditions have been associated with lichen planus?
Oral lichen planus is generally considered a potentially premalignant condition; a 1% incidence of squamous-cell carcinoma has been reported among patients with this condition in both retrospective and prospective cohort studies. The true risk remains controversial. Case reports have also described squamous-cell carcinomas arising from chronic anogenital, esophageal, or hypertrophic cutaneous lichen planus lesions. Several autoimmune disorders, particularly alopecia areata and ulcerative colitis, have been reported to occur more frequently in patients with lichen planus than in control populations. There is also a significant association between lichen planus and infection with hepatitis C virus (HCV). In two meta-analyses, patients with lichen planus were reported to be approximately five times as likely as controls to be HCV-seropositive.
Morning Report Questions
Q: What diagnostic evaluation is necessary when lichen planus is suspected?
A: Lichen planus is usually diagnosed clinically. If a patient has lichen planus at any site, the clinician should examine all potentially involved sites, such as the muscosa, skin, and skin appendages (nails and hair). Specialized otorhinolaryngologic and endoscopic examinations should be considered when related symptoms such as odynophagia or dysphagia are present. A careful drug history is routinely warranted, as drug-induced lichen planus, also known as a lichenoid drug eruption, though uncommon, may be indistinguishable from the idiopathic sub-type. Histologic examination of skin or mucosal biopsy specimens is useful to confirm the diagnosis in atypical cases, as well as in cases of severe disease, and to avoid inappropriate treatment. For persistent lesions that do not disappear with treatment, biopsy should be performed to rule out early dysplasia or squamous-cell carcinoma. Given the recognized associations between lichen planus and HCV infection, screening for anti-HCV antibodies with the use of an enzyme-linked immunosorbent assay (ELISA) is recommended.
Q: How is lichen planus treated?
A: Because the cutaneous form of lichen planus may resolve spontaneously, the goals of therapy are to shorten the time between onset and resolution of the lesions and to reduce itching. Topical glucocorticoids are used as the first-line treatment; topical retinoids are not prescribed for this condition because of the risk of irritation. When topical glucocorticoids are ineffective, oral glucocorticoid therapy is sometimes used. Oral aromatic retinoids are also used, as well as phototherapy, but the latter option should be used cautiously in dark-skinned patients, who have an increased risk of residual hyperpigmentation. For erosive oral lichen planus, topical glucocorticoids are the first-line therapy. Oral glucocorticoids are generally used for erosive lesions that do not respond sufficiently to topical glucocorticoids and as first-line therapy for severe erosive oral lichen planus associated with eating difficulties. For non-erosive oral lesions, either topical corticosteroids or topical retinoids can be used as first-line treatment. For erosive genital lesions, the major therapeutic aim is to prevent or limit scarring. Topical glucocorticoids are most often used. Synechiae formation may be prevented with the use of vaginal dilators and, for uncircumcised men, foreskin retraction.