Lichen planus (LP; see the image below) is a cell-mediated immune response of unknown origin. It may be found with other diseases of altered immunity, such as ulcerative colitis, alopecia areata, vitiligo, dermatomyositis, morphea, lichen sclerosus, and myasthenia gravis. A rare type of LP, familial bullous lichen planus, could be gene-related. LP may be triggered by diuretics and antimalarials, metal fillings (causing oral LP), stress, and infection. It has been found to be associated with hepatitis C virus (HCV) infection.
![]() View Image | Close-up view of lichen planus. |
The following may be noted in the patient history:
In addition to the widespread cutaneous eruption, LP can involve the following structures:
The clinical presentation of LP has several variations, as follows:
See Clinical Presentation for more detail.
Direct immunofluorescence study reveals globular deposits of immunoglobulin M (IgM) and complement mixed with apoptotic keratinocytes. No imaging studies are necessary.
Distinguishing histopathologic features of LP include the following:
See Workup for more detail.
LP is a self-limited disease that usually resolves over several months but can sometimes take years to do so. It recurs in about 20% of patients, and it may linger for years, particularly oral LP. LP commonly results in postinflammatory hyperpigmentation and occasionally leaves hypertrophic scars, which may be the result of scratching. Mild cases can be treated with fluorinated topical steroids. More severe cases, especially those with scalp, nail, and mucous membrane involvement, may necessitate more intensive therapy. Classic idiopathic LP characteristically is highly sensitive to corticosteroid treatment.
Pharmacologic therapies include the following:
Patients with widespread LP may respond to the following:
See Treatment and Medication for more detail.
Lichen planus (LP) is a pruritic eruption that can be associated with hepatitis C. Lesions are characteristically papular, purple or violaceous in color, polygonal, and often peripherally located on the distal extremities. LP has various distinct subtypes and clinical presentations, including but not limited to those affecting the genitalia or mucous membranes. Although the pathophysiology is unclear, it is an immunologically mediated reaction.
LP is a cell-mediated immune response of unknown origin. It may be found with other diseases of altered immunity; such conditions include ulcerative colitis, alopecia areata, vitiligo, dermatomyositis, morphea, lichen sclerosus, and myasthenia gravis.
Associations have been noted between LP and hepatitis C virus (HCV) infection,[8, 9, 10, 11, 12, 13] chronic active hepatitis, and primary biliary cirrhosis.[14] In one meta-analysis, 16% of patients with LP had hepatitis C infection.[10] This association has been shown to exist in all regions of the world, including North America.[11] A workup for hepatitis C should be considered in patients with widespread or unusual presentations of LP. Onset or exacerbation of LP has also been linked to stressful events.[15]
The exact cause of LP has not been established, though the condition is known to be immunologically mediated. The initiating antigen is unclear; however, Langerhans cells process the antigen to T lymphocytes, resulting in an epidermotropic infiltrate. Histologically, the inflammation is described as a lichenoid infiltrate, effacing the dermoepidermal junction.
Some patients with LP have a positive family history.[16] It has been noted that affected families have an increased frequency of human leukocyte antigen (HLA)-B7. Others have found an association between idiopathic LP and HLA-DR1 and HLA-DR10; thus, LP may be influenced by a genetic predisposition.
In the United States, LP is reported in approximately 1% of all new patients seen at health care clinics. Some areas have reported a higher incidence in December and January.
Internationally, no significant geographical variation in frequency exists for LP.
More than two thirds of LP patients are between the ages of 30 and 60 years; however, LP can occur at any age.[17]
No significant differences in the incidence of LP are noted between male and female patients; however, in women, LP may present as desquamative inflammatory vaginitis.[18]
No racial predispositions have been noted for LP.
The prognosis for LP is good, in that most cases regress within 18 months. Some cases recur. In LP, atrophy and scarring are seen in hypertrophic lesions and in lesions on the scalp. Cutaneous LP does not carry a risk of skin cancer, but ulcerative lesions in the mouth, particularly in men, do occasionally exhibit malignant transformation; however, the rate of malignant transformation for oral LP is low (< 2% in one report).[19] Vulvar lesions in women may also be associated with squamous cell carcinoma.
Patients should be informed about the self-limiting nature of LP. Because LP is not common, no large randomized controlled clinical trials have been conducted for therapy. It may be necessary to try several different treatments. Patients should also be told about the small likelihood of recurrence and the potential adverse effects from the various treatments offered.
Most cases of lichen planus (LP) are insidious. Lesions usually develop on flexural surfaces of the limbs, such as the wrists (see the image below). After a week or more, a generalized eruption develops with maximal spreading within 2-16 weeks.
![]() View Image | Lichen planus on flexor part of wrist. |
Pruritus is common in LP but varies in severity, depending on the type of lesion and the extent of involvement. Hypertrophic lesions are extremely pruritic.
Oral lesions may be asymptomatic or give rise to a burning sensation, or they may even be painful if erosions are present.
In more than 50% of cases of cutaneous LP, the lesions resolve within 6 months, and 85% of cases subside within 18 months. On the other hand, oral LP has been reported to have a mean duration of 5 years. Large, annular, hypertrophic lesions and mucous membrane involvement are more likely to become chronic.
In addition to the cutaneous eruption, LP can involve the mucous membranes, the genitalia, the nails, and the scalp. The clinical presentation of LP has several forms: actinic (in sun-exposed areas), annular, atrophic, erosive, follicular, hypertrophic, linear, pigmented, and vesicular/bullous. The papules are violaceous, shiny, and polygonal, ranging in diameter from 1 mm to more than 1 cm (see the first image below). They can be discrete or arranged in groups of lines or circles. Characteristic fine white lines, called Wickham striae, are often found on the papules (see the second image below).
![]() View Image | Close-up view of lichen planus. |
![]() View Image | Lichen planus shows Wickham striae (white, fine, reticular lines). |
Mucous membrane involvement is common and may be found in patients who do not have skin involvement. Lesions are most commonly on the tongue and the buccal mucosa; they are characterized by white or gray streaks forming a linear or reticular pattern on a violaceous background (see the image below). Oral lesions are classified as reticular, plaquelike, atrophic, papular, erosive, or bullous. Ulcerated oral lesions may have a higher incidence of malignant transformation in men, but this observation may be confounded by other factors (eg, smoking and chewing tobacco).
![]() View Image | Lichen planus on oral mucosa with ulceration in center of lesion appears with whitish papules and plaques in periphery. |
Lesions may also be found on the conjunctivae, the larynx, the esophagus, the tonsils, the tympanic membrane, the bladder, the vulva, and the vaginal vault; throughout the gastrointestinal (GI) tract; and around the anus.
Genital involvement is common in LP. Typically, men develop annular lesions on the glans. Wickham striae may also be observed on these lesions. Vulvar involvement can range from reticulate papules to severe erosions. Dyspareunia, a burning sensation, and pruritus are common in women. Vulvar and urethral stenosis may be a complication. It is estimated that more than 50% of women with oral LP also had undiagnosed vulvar LP.[20, 21]
Nail findings are noted in roughly 10% of patients with LP, the most common being longitudinal grooving and ridging. Hyperpigmentation, subungual hyperkeratosis, onycholysis, and longitudinal melanonychia can result from LP. Rarely, inflammation may result in permanent destruction of the nail matrix with subsequent pterygium formation. LP has been linked to childhood idiopathic nail atrophy and may overlap with 20-nail dystrophy of childhood.
Cutaneous lesions may be accompanied by follicular and perifollicular lesions on the scalp, which may be violaceous, scaly, and pruritic papules. These lesions can progress to atrophic cicatricial alopecia, known as lichen planopilaris. This can appear even many weeks after the skin lesions have disappeared. Pseudopelade can be a final endpoint.
Variations in the presentation of LP include the following.
Hypertrophic lichen planus
These extremely pruritic lesions are most often found on the extensor surfaces of the lower extremities, especially around the ankles. Hypertrophic lesions are often chronic; residual pigmentation and scarring can occur when the lesions eventually clear.
Atrophic lichen planus
Atrophic LP is characterized by a few lesions, which are often the resolution of annular or hypertrophic lesions.
Erosive/ulcerative lichen planus
These lesions are found on the mucosal surfaces and evolve from sites of previous LP involvement. A rare variant of lichen planus is vulvovaginal-gingival syndrome,[22] which is characterized by erosions and desquamation of the mucosa in the vulvar, vaginal, and gingival regions. It can be associated with mucocutaneous scarring and vaginal stricture formation.
Follicular lichen planus (lichen planopilaris)
This form of LP is characterized by keratotic papules that may coalesce into plaques. It is more common in women than in men, and ungual and erosive mucosal involvement is more likely to be present. A scarring alopecia may result. A variant of lichen planopilaris is frontal fibrosing alopecia, which is characterized by marginal progressive hair loss on the scalp, eyebrows, and axillae.[23]
Another variant of follicular LP is Graham-Little-Piccardi-Lasseur syndrome.[24] Features of this syndrome include progressive scalp cicatricial alopecia, noncicatricial alopecia of the axillae and pubic areas, and keratosis pilaris–like follicular papules over the trunk and extremities.
Annular lichen planus
LP papules that are purely annular are rare. Annular lesions with an atrophic center can be found on the buccal mucosa and the male genitalia.
Linear lichen planus
Isolated linear lesions may form a zosteriform lesion, or they may develop as a Köbner effect.
Vesicular and bullous lichen planus
Most commonly, these lesions develop on the lower limbs or in the mouth from preexisting LP lesions.
Actinic lichen planus
Subtropic or actinic LP occurs in regions such as Africa, the Middle East, and India. This mildly pruritic eruption usually spares the nails, the scalp, the mucous membranes, and covered areas. Lesions are characterized by nummular patches with a hypopigmented zone surrounding a hyperpigmented center.
Lichen planus pigmentosus
This form of LP is rare but can be more common in persons with darker-pigmented skin, such as those of Latin or Asian descent. It usually appears on the face and neck. Some believe that it is similar to or the same as erythema dyschromicum perstans (ie, ashy dermatosis).
Lichen planus pemphigoides
This is a rare form in which blisters subsequently develop on LP lesions. Clinically, histopathologically, and immunopathologically, it has features of LP and bullous pemphigoid, but it carries a better prognosis than pemphigoid.
Malignant transformation has been reported in ulcerative oral LP. [25] Cutaneous hypertrophic LP resulting in squamous cell carcinoma (SCC) was reported in a series of 38 patients.[26] Pruritic and painful vulvar LP has been a precursor to SCC in a small number of cases.
Infection, osteoporosis, adrenal insufficiency, bone-marrow suppression, renal damage, hyperlipidemia, and growth restriction in children may occur from adverse effects of medication. Postinflammatory/residual hyperpigmentation may be a common marker after LP has subsided. Alopecia associated with LP is often permanent.
Hepatitis C virus (HCV) infection may be present in as many as 16% of LP patients. Additionally, a meta-analysis reported that HCV seropositivity could be as much as six times higher in oral LP patients than in control subjects.[8]
Direct immunofluorescence study in lichen planus (LP) reveals globular deposits of immunoglobulin M (IgM) and complement mixed with apoptotic keratinocytes.
The histopathologic features distinguish lichen planus based on the presence of irregular acanthosis and colloid bodies in the epidermis with destruction of the basal layer. The upper dermis has a bandlike ("lichenoid") infiltrate of lymphocytes and histiocytes.
The inflammatory reaction pattern is characteristic. (See the images below.) The epidermis is hyperkeratotic with irregular acanthosis and focal thickening in the granular layer. Degenerative keratinocytes, known as colloid or Civatte bodies, are found in the lower epidermis. In addition to apoptotic keratinocytes, colloid bodies are composed of globular deposits of IgM (occasionally immunoglobulin G [IgG] or immunoglobulin A [IgA]) and complement. Linear or shaggy deposits of fibrin and fibrinogen are noted in the basement membrane zone.
![]() View Image | Bandlike infiltrate of lymphocytes obscures dermoepidermal junction. Eosinophilic apoptotic keratinocytes (colloid bodies) are visible. Image from Cla.... |
![]() View Image | Higher-power view. Wedge-shaped hypergranulosis and individual degenerated keratinocytes are visible in addition to hyperkeratosis. Vacuolar degenerat.... |
The upper dermis has a bandlike infiltrate of lymphocytic (primarily helper T) and histiocytic cells with many Langerhans cells. The infiltrate is very close to the epidermis and often disrupts the dermal-epidermal junction.
Lichen planus (LP) is a self-limited disease that usually resolves over several months but can sometimes take years to do so. Mild cases can be treated with fluorinated topical steroids. More severe cases, especially those with scalp, nail, and mucous membrane involvement, may need more intensive therapy.
The first-line treatments of cutaneous LP are topical steroids, particularly class I or II ointments. A second choice would be systemic steroids for symptom control and possibly more rapid resolution. Classic LP frequently is very responsive to modest doses of corticosteroids.
Oral metronidazole has been shown to be an effective therapy for some patients.[3] Oral acitretin has been shown to be effective in published studies.[27] Many other treatments, including mycophenolate mofetil at 1-1.5 g twice daily, are of uncertain efficacy, owing to the paucity of experience. In a randomized double-blind study, administration of sulfasalazine at up to 2.5 g/day for 6 weeks led to improvement in lesions (>80%) and pruritus (>90%) in patients with generalized LP.[4]
For LP of the oral mucosa, topical steroids are usually tried first. Topical and systemic cyclosporine regimens have been tried with some success[28] ; however, a randomized double-blind study indicated that topical cyclosporine was a less effective but much more costly regimen than clobetasol.[29] Newer topical calcineurin inhibitors (eg, tacrolimus and pimecrolimus) have replaced topical cyclosporine for the treatment of LP. Other options include oral or topical retinoids. Even with these effective treatments, relapses are common.
Close monitoring of lipid levels is suggested for patients with LP who are treated with oral retinoid agents because a case control study found that the risk of dyslipidemia in these patients is increased two- to threefold.[6] In fact, according to a meta-analysis of 5242 patients, even those who did not receive retinoids might still have dyslipidemia.
Patients with widespread LP may respond to narrowband or broadband ultraviolet (UV)-B therapy.[7] Psoralen with UV-A (PUVA) therapy for 8 weeks has been reported to be effective. PUVA therapy typically consists of oral psoralen 0.6 mg/kg administered 1.5-2 hours before UV-A treatment, which usually starts at 0.5-1 J/cm2 and is increased by 0.5 J/cm2 per visit. Use of topical ointment at the time of UV-A treatment may decrease the effectiveness of PUVA.
The risks and benefits of PUVA should be considered. PUVA is carcinogenic. Long-term risks include dose-related actinic degeneration, squamous cell carcinoma, and cataracts. A phototoxic reaction with erythema, pruritus, phytophotodermatitis, and friction blisters could occur. Precautions should be taken for persons with a history of skin cancers or hepatic insufficiency.
Apremilast may be an effective treatment for LP, but double-blind controlled trials are lacking.[5, 30]
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