Lichen Planus


Key Points

  • Lichen planus (LP) is a pruritic eruption that may be self-limited or chronic, and may affect skin, mucosa (including the esophagus), and hair.
  • The classic morphology of lichen planus is violaceous-to-purple, flat-topped polygonal papules, often with a white-to-lavender reticulate overlying scale (Wickham’s striae). They may occur in areas of prior trauma or injury (koebnerization).
  • The prevalence of hepatitis C viral (HCV) infection-not hepatitis B-is higher in patients with lichen planus; viral screening should be considered for patients with lichen planus, especially if potential HCV risk factors are present.
  • Different variants of lichen planus exist: oral, follicular, erosive, actinic lichen planus, lichen planus pigmentosum, annular, atrophic, bullous, and hypertrophic.
  • Erosive forms of lichen planus, especially of the oral mucosa, genitalia, and rarely of the skin, may be complicated by the development of squamous cell carcinoma.
  • Lichen planus may be triggered by or found in association with exogenous factors, such as medications or contact allergens; a treatable cause should always be sought. Nearly 40% of patients with oral lichen planus may have a contact hypersensitivity to metallic dental prosthetics (containing mercury, copper, or gold).
  • Treatment of lichen planus may involve high-potency topical corticosteroids but may require systemic immunosuppression in severe cases.

Introduction

Lichen planus may be self-limited or chronic and presents as localized or generalized disease, usually with mild to severe pruritus. It affects 0.5-2% of the population, with women more commonly affected than men (3:1 female to male ratio in one study), presenting typically between the fourth and sixth decade of life. Lesions of lichen planus may present across a wide clinical spectrum and distribution. Occasionally, patients have ulcerative, painful lesions; such erosive lesions of lichen planus may be complicated by the development of squamous cell carcinoma. Patients with lichen planus are now recognized to have a higher prevalence of HCV infection (odds ratio of 4.85, 95% CI, 3.58-6.56) than in individuals who do not have lichen planus (see references Lodi et al., 2010 and Birkenfeld et al., 2011); there is no known association between lichen planus and hepatitis B viral infection. Screening for HCV should be strongly considered for patients with lichen planus, especially if potential HCV risk factors are present.

The aim of therapy is to control symptoms, and therefore must be appropriate to the extent and severity of the disease. Given that the disease is often chronic in nature, a judicious approach to controlling inflammation is advised. Localized forms can often be managed with topical or intralesional therapy; in rare severe cases, or in cases where scarring or alopecia can result, systemic immunosuppression should be considered. Generalized forms often require systemic treatment, such as immunosuppression or phototherapy. Specific variants, such as erosive disease, require additional monitoring for evolution of squamous cell carcinoma, a rare clinical complication of the disease in which the true incidence is controversial.

Initial Evaluation

Lesions of lichen planus are marked by violaceous-to-purple flat-topped papules, often with a white-to-lavender reticulate overlying scale (Wickham’s striae). Patients report intense pruritus and sometimes koebnerization (development of lesions at areas of trauma/ injury). Presentation is almost always bilateral and symmetric. Oral mucosa is commonly affected (15% of cases), and buccal mucosal disease is present in 90% of cases of oral lichen planus. When oral involvement is present, patients may subjectively complain of discomfort, stinging, or pain due to hot foods and drinks. Lesions may be found less frequently around the anus and on the genitalia. When the palms and soles are affected, the lesions may be firm and rough with a yellowish hue.

Ungual

Variants

LP principally involving mucous membranes

Lesions confined to the mouth or with minimal accompanying skin involvement are not uncommon and account for about 15% of all cases. Distinct clinical subtypes of oral lichen planus are well recognized: reticular, atrophic, hypertrophic and erosive.

Erosive

Hypertrophic lichen planus most often occurs on the lower limbs, especially around the ankles. Malignant transformation has been reported.

Follicular disease, also known as lichen planopilaris, is often associated with scarring hair loss and may present on the vertex (classic lichen planopilaris), with frontal accentuation (frontal fibrosing alopecia), or with lichenoid rash, scaly scalp patches, and noncicatricial loss of axillary and pubic hair (Lassueur-Graham-Little-Piccardi syndrome).

Other variants include actinic lichen planus (photodistributed), lichen planus pigmentosum, annular, atrophic and bullous lichen planus.

Differential diagnosis

Leukocytoclastic vasculitis, or palpable purpura, presents as violaceous-to-purpuric papules occasionally with a central pustule, vesiculation, or necrosis often in dependent areas, such as the legs, hips, and buttocks.

Lichen nitidus appear as very small (1-2 mm) monomorphous, flat-topped, shiny papules that are grouped within a discrete area. They sometimes occur in sun-exposed areas.

Lymphomatoid papulosis presents as scattered, crusted erythematous papules to small nodules.

Cutaneous T cell lymphoma lesions may present as erythematous-to-violaceous patches, plaques, to nodules, typically on the trunk.

Lesions of lupus erythematosus may present as purple-to-violaceous raised papules and plaques. Central hypopigmentation with scarring, peripheral hyperpigmentation, and alopecia may be clues to discoid lupus. Annular erythematous-to-violaceous plaques, especially in photodistributed regions, may be a clue to subacute lupus.

Secondary syphilis

Treatment

Localized lichen planus

Initial therapy

First-line treatment: Superpotent topical steroid ointment or cream. Apply superpotent fluorinated topical steroid ointment or cream such as fluocinonide (such as Lidex), betamethasone (such as Diprolene), or clobetasol proprionate (such as Temovate) q.d. to b.i.d. until the lesions flatten and disappear.

Prescribe an antihistamine to control pruritus. During waking hours, loratadine 10 mg (such as Claritin), cetirizine 5-10 mg (such as Zyrtec), or fexofenadine 60-180 mg (such as Allegra) may be taken. Before bed, diphenhydramine (such as Benadryl) 50-100 mg or hydroxyzine (such as Atarax) 1-2 mg/kg may be taken.

Subsequent therapy

  • Reduce the superpotent fluorinated topical steroid to a medium-potency agent (e.g., triamcinolone acetonide (Kenalog) 0.1% ointment or cream q.d. to b.i.d.) and apply as necessary to control lesions.
  • Reduce antihistamines to levels necessary to control pruritus.

Generalized lichen planus

Initial therapy

First-line treatment: Treat with oral prednisone (or an equivalent steroid) at 40-60 mg/day. Maintain the dose until symptoms abate and lesions clear (approximately 2-6 weeks).

While treatment with systemic steroids leads to rapid improvement, generalized LP almost invariably relapses as the steroids are tapered. Therefore, systemic steroids should only be used when absolutely necessary.

Subsequent therapy

Taper prednisone at a rate of 10 mg/week until a dose of 20 mg q .d. is reached, then taper by 5 mg/week. Expect recurrence when the dose reaches 20-30 mg/day and control with topical steroids if possible. All patients will clear, but only about 25% will remain disease free. Patients who have a recurrence must be weaned from steroids. Other steroid-sparing alternatives (see below) should be employed.

Alternative therapy

  • Photochemotherapy (PUVA) may be helpful in rare cases. Treat 3 times a week and expect a response in 3-6 weeks. Narrowband UVB may also be effective at 3 times per week.
  • Acitretin (Soriatane) 0.25-1 mg/kg/day or isotretinoin (such as Claravis, Sotret) 0.5-1 mg daily.
  • Hydroxychloroquine 200 mg once to twice daily. This medication may have significant ocular toxicity and a baseline ophthalmologic exam should be performed prior to initiating the medication and every 3-6 months while on treatment.

Oral lichen planus

Most nonulcerative cases are asymptomatic and do not require therapy. Ulcerative disease is often symptomatic and should be treated. Oral lichen planus may affect the oropharynx and the esophagus, and patients should be asked about dysphagia as a screening for pharyngeal or esophageal disease. Forty percent of females with erosive oral LP also have erosive vulvar lesions but do not identify them to their dermatologist unless specifically queried. Lesions are frequently misdiagnosed as genital lichen sclerosus. Erosive genital lesions are treated identically to oral lesions.

If the patient responds to treatment, continue as required. Patients with ulcerative disease must be followed for the development of oral or genital squamous cell carcinoma.

Optimal oral hygiene is an important adjunctive intervention in the management of oral lichen planus. Furthermore, eliminate potential sources of trauma to the mouth, including smoking; hot, acidic or crunchy foods; or ill-fitting dental appliances (such as dentures, retainers, bridges).

Because oral lichen planus may be found in association with or triggered by allergy to dental materials (especially metals), patch testing should be considered.

Initial therapy

  • Apply fluorinated steroids in a gelatin dental paste (betamethasone or clobetasol in Orabase) t.i.d. to q.i.d.
  • Inject lesions with triamcinolone acetonide 5-10 mg/cc using a 30-gauge needle. Lesions may be injected every 2-3 weeks, up to 3-4 times if necessary.
  • Use a medicated mouth rinse such as dexamethasone 5 mg/cc, (such as Decadron or Hexadrol – use 5 cc per rinse) or cyclosporine (100 mg/cc, 5 cc per rinse) that is gargled for 15-30 seconds and then spit out, 3 times daily.
  • Apply topical anesthetic (viscous lidocaine) as needed.
  • For disease of the gingivae, a dental tray may enhance therapy.
  • Oral and vulval erosive disease is frequently complicated by secondary infection with Candida albicans. Topical anticandidal therapy with nystatin solution swish/spit, nystatin troches, or systemic fluconazole 6 mg/kg daily for one week, then 6 mg/kg every week, will control this complication and make the management of the mucosal disease much easier.

Alternative therapy

Tacrolimus ointment 0.1% (such as Protopic) applied twice daily or tretinoin 0.05% cream or gel (such as Atralin, Refissa, Retin-A) applied once daily.

Subsequent therapy

If symptoms cannot be controlled, systemic steroids as given for widespread lichen planus, are appropriate.

Pitfalls

  • Lichen planus may be drug induced. Commonly used culprits include thiazides, gold, quinidine, and chloroquine. Discontinue these agents. In the case of gold-induced lichen planus, resolution may take months.
  • Lesions of oral lichen planus have been reported in associated with dental mercurial amalgams or other dental prosthetics and likely reflect a hypersensitivity reaction. Individuals with recalcitrant lesions on the buccal mucosa in contact with amalgam dental work should be referred to a dentist/ orthodontist for evaluation and possible dental restoration.
  • Most cases of lichen planus resolve spontaneously. Do not use long-term, chronic systemic steroid therapy to control lesions. Rather, aim for control of symptoms, employing topical care if possible.

When to refer to a dermatologist

  • If the diagnosis of lichen planus is not clear.
  • For management of rapidly evolving or recalcitrant disease, especially requiring systemic immunosuppression or phototherapy.
  • For management and screening of oral lesions, especially if they are erosive.

Clinical Cases

Case 1

Generalized cutaneous and mucosal lichen planus

  • 53-year-old man with hepatitis C viral infection
  • Acute onset of intensely pruritic, purpuric, papular eruption
  • No constitutional symptoms

Initial evaluation

  • Bilateral symmetric distribution of 3-5 mm violaceous, flat-topped papules on arms (accentuated on wrists), legs, penis, and lower mucosal lip
  • A skin biopsy confirms the diagnosis
  • Topical and systemic corticosteroids are discussed; the patient prefers to start on topical therapy because of his HCV disease. Patient is started on topical fluocinonide ointment under occlusion b.i.d.
  • Antihistamines (hydroxyzine 25 mg at bedtime) given
  • Follow-up in 2 weeks

Two-week follow-up evaluation

  • Minimal reduction in lesions, although pruritus is improved on antihistamines
  • Prednisone 0.25 mg/kg daily dose started; persistent disease leads to starting PUVA therapy on top of prednisone therapy, which leads to full resolution of skin lesions
  • Patient successfully tapered off prednisone therapy
  • Intermittent lichen planus managed with topical corticosteroid therapy (clobetasol propionate) ointment t.i.d. and maintenance phototherapy.

Case 2

Oral lichen planus

  • 17-year-old healthy teenage girl who presents with “oral ulcers”
  • No history of tobacco, smoking, alcohol consumption
  • No recent dental implants or dental work
  • Denies dysphagia

Initial evaluation

  • Widespread buccal mucosal involvement with lavender ill-defined reticular plaques with Wickham’s striae overlying
  • No cutaneous lesions
  • Patient is given topical clobetasol ointment to apply to the bilateral buccal mucosa
  • Follow-up evaluation in 4 weeks

Four-week follow-up evaluation

  • Lesions are 50% reduced in number and distribution
  • Patient is not certain where to apply medication
  • Switched to dexamethasone swish/spit: 5 cc t.i.d. (when disease is active)
  • Nystatin troches (used daily to b.i.d.) are also given, to be used with dexamethasone use
  • Disease resolved: minimal flares 1-2 times a year, responsive to dexamethasone treatment

References

Assouly P and Reygagne P (2009) Lichen planopilaris: update on diagnosis and treatment, Semin Cutan Med Surg, 28:3-10.

Asch S and G Goldenberg (2011) Systemic treatment of cutaneous lichen planus: an update, Cutis, 87:129-134.

Birkenfeld S et al (2011) A study on the association with hepatitis B and hepatitis C in 1557 patients with lichen planus, JEADV, 25(4): 436-440.

Lodi G et al (2010) HCV infection and lichen planus: a systematic review with meta-analysis, Oral Diseases, 16:601-612.

Schlosser BJ (2010) Lichen planus and lichenoid reactions of the oral mucosa, Dermatologic Therapy, 23:251-267.