eMedicine Specialties > Dermatology > Reactive & Inflammatory Dermatoses
Lichen Planus
Updated: Oct 16, 2009
Introduction
Background
Lichen planus (LP) is a pruritic, papular eruption characterized by its violaceous color; polygonal shape; and, sometimes, fine scale. Lichen planus is most commonly found on the flexor surfaces of the upper extremities, on the genitalia, and on the mucous membranes. Lichen planus is most likely an immunologically mediated reaction. See Oral Lichen Planus for more information on this variant of lichen planus.
Pathophysiology
Lichen planus is a cell-mediated immune response of unknown origin.
Lichen planus may be found with other diseases of altered immunity; these conditions include ulcerative colitis, alopecia areata, vitiligo, dermatomyositis, morphea, lichen sclerosis, and myasthenia gravis.
An association is noted between lichen planus and hepatitis C virus infection,1,2,3 chronic active hepatitis, and primary biliary cirrhosis.4 In a meta-analysis, 16% of patients with lichen planus had hepatitis-C infection.2 The association of lichen planus and hepatitis C exists in all regions of the world, including North America.3 Hepatitis should be considered in patients with widespread or unusual presentations of lichen planus. Onset or exacerbation of lichen planus has been linked to stressful events.5
Frequency
United States
Lichen planus 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.
International
No significant geographical variation in frequency exists.
Mortality/Morbidity
Atrophy and scarring are seen in hypertrophic lesions and lesions on the scalp. Cutaneous lichen planus does not have a higher risk of skin cancer, but ulcerative lesions in the mouth, particularly in men, have a higher incidence of malignant transformation. However, in general, the malignant transformation rate of oral lichen planus is low (<2% in one report).6 Vulvar lesions in women may also be associated with squamous cell carcinoma.
Race
No racial predispositions have been noted.
Sex
No significant differences in incidence are noted between male and female patients, but in women, lichen planus may present as desquamative inflammatory vaginitis.7
Age
More than two thirds of patients are aged 30-60 years; however, lichen planus can occur at any age.8
Clinical
History
Most cases of lichen planus (LP) are insidious.
- The initial lesion is usually located on the flexor surface of the limbs, such as the wrists (see Media File 1). After a week or more, a generalized eruption develops with maximal spreading within 2-16 weeks.
- Pruritus is common 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 have a burning sensation, or they may even be painful if erosions are present.
- In more than 50% of patients with cutaneous disease, the lesions resolve within 6 months, and 85% of cases subside within 18 months. On the other hand, oral lichen planus had been reported to have a mean duration of 5 years. Large, annular, hypertrophic lesions and mucous membrane involvement are more likely to become chronic.
Lichen planus on the flexor part of the wrist.
Physical
In addition to the cutaneous eruption, lichen planus (LP) can involve the mucous membranes, the genitalia, the nails, and the scalp. The clinical presentation of lichen planus has several forms: actinic, annular, atrophic, erosive, follicular, hypertrophic, linear, pigmented, and vesicular/bullous. The papules are violaceous, shiny, and polygonal; varying in size from 1 mm to greater than 1 cm in diameter (see Media File 2). They can be discrete or arranged in groups of lines or circles. Characteristic fine, white lines, called Wickham stria, are often found on the papules (see Media File 3).
Close-up view of lichen planus.
Lichen planus shows Wickham striae (white, fine, reticular scales).
- Mucous membrane involvement is common and may be found without skin involvement. Lesions are most commonly found 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 Media File 4). Oral lesions are classified as reticular, plaquelike, atrophic, papular, erosive, and bullous. Ulcerated oral lesions may have a higher incidence of malignant transformation in men, but this observation may be confounded by other factors, such as smoking and chewing tobacco. Lesions may also be found on the conjunctivae, the larynx, the esophagus, the tonsils, the bladder, the vulva, and the vaginal vault; throughout the gastrointestinal tract; and around the anus.
Lichen planus on the oral mucosa with ulceration in the center of the lesion appears with whitish papules and plaques in the periphery.
- Genital involvement is common in men with cutaneous disease. Typically, an annular configuration of papules is seen on the glans. Less commonly, linear white striae, similar to the lesions on the vulva and the vagina, can be seen on male genitalia. Vulvar involvement can range from reticulate papules to severe erosions. Dyspareunia, a burning sensation, and pruritus are common. Vulvar and urethral stenosis can also be present. Two reports documented that more than 50% women with oral lichen planus had undiagnosed vulvar lichen planus.9,10 Also see the clinical guideline summary, Diagnosis and management of vulvar skin disorders.11
- In 10% of patients, ungual findings are present. Most commonly, nail plate thinning causes longitudinal grooving and ridging. Hyperpigmentation, subungual hyperkeratosis, onycholysis, and longitudinal melanonychia can result from lichen planus. Rarely, the matrix can be permanently destroyed with prominent pterygium formation. Lichen planus has been linked to childhood idiopathic nail atrophy and may overlap with twenty-nail dystrophy of childhood.
- Patients with a cutaneous eruption may also have follicular and perifollicular violaceous, scaly, pruritic papules on the scalp. These lesions can progress to atrophic cicatricial alopecia that can appear many weeks after the skin lesions have disappeared. Pseudopelade can be a final endpoint.
- Variations in lichen planus 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 lichen planus 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 lichen planus involvement.
- Follicular lichen planus: Lichen planopilaris is characterized by keratotic papules that may coalesce into plaques. This condition 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.
- Annular lichen planus: Lichen planus 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 lichen planus lesions. A rare condition, lichen planus pemphigoides, is a combination of both lichen planus and bullous pemphigoid.
- Actinic lichen planus: Subtropic or actinic lichen planus 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 is a rare variant of lichen planus but can be more common in persons with darker-pigmented skin, such as Latinos or Asians. It usually appears on face and neck. Some believe it is similar to or the same as erythema dyschromicum perstans (ie, ashy dermatosis).
- Lichen planus pemphigoides: This is a rare form of lichen planus. Blisters subsequently develop on lichen planus lesions. Clinically, histopathologically and immunopathologically, it has features of lichen planus and bullous pemphigoid, it but carries a better prognosis than pemphigoid.
Causes
The exact cause of lichen planus (LP) is not known. The pathogenesis of lichen planus is immunologically mediated. Whether the foreign antigen is a virus or a drug is not known. Langerhans cells process antigens, which are then presented to T lymphocytes. This stimulated lymphocytic infiltrate is epidermotropic and attacks keratinocytes. During this lymphocytotoxic process, the keratinocytes release cytokines that attract more lymphocytes. This process has been referred to as the lichenoid tissue reaction. In addition, recent studies reveal a disruption in the epithelial anchoring system.
Some patients with lichen planus have a positive family history. It has been noted that affected families have an increased frequency of human leukocyte antigen B7 (HLA-B7). Others have found an association between idiopathic lichen planus and human leukocyte antigen DR1 (HLA-DR1) and human leukocyte antigen DR10 (HLA-DR10); thus, lichen planus may be influenced by a genetic predisposition.
More on Lichen Planus |
 Overview: Lichen Planus |
| Differential Diagnoses & Workup: Lichen Planus |
| Treatment & Medication: Lichen Planus |
| Follow-up: Lichen Planus |
| Multimedia: Lichen Planus |
| References |
| Next Page » |
References
Chuang TY, Stitle L, Brashear R, Lewis C. Hepatitis C virus and lichen planus: A case-control study of 340 patients. J Am Acad Dermatol. Nov 1999;41(5 Pt 1):787-9. [Medline].
[Best Evidence] Shengyuan L, Songpo Y, Wen W, Wenjing T, Haitao Z, Binyou W. Hepatitis C virus and lichen planus: a reciprocal association determined by a meta-analysis. Arch Dermatol. Sep 2009;145(9):1040-7. [Medline].
Bigby M. The relationship between lichen planus and hepatitis C clarified. Arch Dermatol. Sep 2009;145(9):1048-50. [Medline].
Korkij W, Chuang TY, Soltani K. Liver abnormalities in patients with lichen planus. A retrospective case-control study. J Am Acad Dermatol. Oct 1984;11(4 Pt 1):609-15. [Medline].
Manolache L, Seceleanu-Petrescu D, Benea V. Lichen planus patients and stressful events. J Eur Acad Dermatol Venereol. Apr 2008;22(4):437-41. [Medline].
Ingafou M, Leao JC, Porter SR, Scully C. Oral lichen planus: a retrospective study of 690 British patients. Oral Dis. Sep 2006;12(5):463-8. [Medline].
Murphy R, Edwards L. Desquamative inflammatory vaginitis: what is it?. J Reprod Med. Feb 2008;53(2):124-8. [Medline].
Balasubramaniam P, Ogboli M, Moss C. Lichen planus in children: review of 26 cases. Clin Exp Dermatol. Jul 2008;33(4):457-9. [Medline].
Belfiore P, Di Fede O, Cabibi D, et al. Prevalence of vulval lichen planus in a cohort of women with oral lichen planus: an interdisciplinary study. Br J Dermatol. Nov 2006;155(5):994-8. [Medline].
Di Fede O, Belfiore P, Cabibi D, et al. Unexpectedly high frequency of genital involvement in women with clinical and histological features of oral lichen planus. Acta Derm Venereol. 2006;86(5):433-8. [Medline].
[Guideline] American College of Obstetricians and Gynecologists. Diagnosis and management of vulvar skin disorders. National Guideline Clearinghouse. May 2008.
Cribier B, Frances C, Chosidow O. Treatment of lichen planus. An evidence-based medicine analysis of efficacy. Arch Dermatol. Dec 1998;134(12):1521-30. [Medline].
Lim KK, Su WP, Schroeter AL, Sabers CJ, Abraham RT, Pittelkow MR. Cyclosporine in the treatment of dermatologic disease: an update. Mayo Clin Proc. Dec 1996;71(12):1182-91. [Medline].
Conrotto D, Carbone M, Carrozzo M, Arduino P, Broccoletti R, Pentenero M, et al. Ciclosporin vs. clobetasol in the topical management of atrophic and erosive oral lichen planus: a double-blind, randomized controlled trial. Br J Dermatol. Jan 2006;154(1):139-45. [Medline].
Pavlotsky F, Nathansohn N, Kriger G, Shpiro D, Trau H. Ultraviolet-B treatment for cutaneous lichen planus: our experience with 50 patients. Photodermatol Photoimmunol Photomed. Apr 2008;24(2):83-6. [Medline].
Gonzalez-Moles MA, Scully C, Gil-Montoya JA. Oral lichen planus: controversies surrounding malignant transformation. Oral Dis. Apr 2008;14(3):229-43. [Medline].
Boyd AS, Neldner KH. Lichen planus. J Am Acad Dermatol. Oct 1991;25(4):593-619. [Medline].
Champion RH, ed. Rook/Wilkinson/Ebling Textbook of Dermatology. Vol 3. 6th ed. Malden, Mass: Blackwell Science; 1998:199-1916.
Fitzpatrick T, Eisen A, Wolff K, et al. Dermatology in General Medicine. Vol 1. 4th ed. New York, NY: McGraw-Hill; 1993:1134-44.
Lewis FM. Vulval lichen planus. Br J Dermatol. Apr 1998;138(4):569-75. [Medline].
Murphy R, Edwards L. Desquamative inflammatory vaginitis: what is it?. J Reprod Med. Feb 2008;53(2):124-8. [Medline].
Further Reading
Keywords
lichen planus, LP, actinic lichen planus, annular lichen planus, atrophic lichen planus, erosive lichen planus, follicular lichen planus, guttate lichen planus, hypertrophic lichen planus, linear lichen planus, vesicular lichen planus, papular eruption, Wickham stria, hyperpigmentation, subungual hyperkeratosis, onycholysis, longitudinal melanonychia, atrophic cicatricial alopecia, pseudopelade, HLA-B7, HLA-DR1, HLA-DR10
