Lichen Planus
Jill C. Cash, Amy C. Bruggemann, and Cheryl A. Glass
Definition
A.Lichen planus is a relatively uncommon condition of acute or chronic inflammatory dermatosis. It affects skin and mucous membranes with characteristic flat-topped, shiny, violaceous (purplish color) pruritic papules with lacy lines on the skin, and milky-white papules in the mouth.
Incidence
A.Lichen planus accounts for 0.1% to 1.2% of office visits to dermatologists.
B.It exhibits no racial preference.
Pathogenesis
A.Etiology is unknown, although it is possibly a cell-mediated immune response. Most cases remit within 7 years. Lesions may heal with significant postinflammatory hyperpigmentation.
Predisposing Factors
A.Severe emotional stress.
B.Drugs may induce lichenoid plaques.
Common Complaints
A.Rash with or without pruritus.
B.Primary lesions: Small, flat-topped papules or plaques that are polygonal, lightly scaly, and violaceous.
C.Secondary lesions: Erythema, scales, and erosions.
Other Signs and Symptoms
A.Distribution: Volar aspect of wrists, ankles, mouth, genitalia, and lumbar region.
B.Wickham’s striae (white, lacelike pattern on surface).
C.Scalp: Atrophic skin with alopecia.
D.Nails: Destruction of nail fold and bed, especially in large toe.
E.Men: Lesions of glans penis.
F.Women: Erosive lesions of labia and vulva.
Subjective Data
A.Determine whether the onset was sudden or gradual.
B.Ask the patient to describe if the skin is itchy or painful.
C.Assess lesions for any associated discharge (blood or pus).
D.Identify the location(s) of the problem.
E.Complete a drug history. Ask the patient if he or she has recently taken any antibiotics or other drugs. Ask if he or she has used any topical medications, lotions, or other creams.
F.Determine the presence of any preceding systemic symptoms (fever, sore throat, anorexia, or vaginal discharge).
G.Rule out insect bites.
H.Identify any possible exposure to industrial toxins, domestic toxins, or color-film-developing chemicals.
I.Ask if the patient has had any possible sexual contacts with persons with HIV or sexually transmitted infections (STIs).
J.Ask if the patient has had close physical contact with others with skin disorders.
Physical Examination
A.Inspect:
1.Inspect skin and note lesion distribution.
2.Inspect mucous membranes: Buccal mucosa, tongue, and lips.
3.Examine hair and nails.
4.Observe genitalia.
Diagnostic Tests
A.Dermoscopy to accentuate Wickham’s striae.
B.If necessary to confirm diagnosis, deep shave or punch biopsy of developed lesions.
C.HIV or STI testing if indicated.
Differential Diagnoses
A.Lichen planus.
B.Lichenoid drug eruptions.
C.Leukoplakia.
D.Chronic graft-versus-host disease.
E.Candidiasis (thrush).
F.Lupus erythematosus.
G.Contact dermatitis.
H.Bite trauma.
I.Secondary syphilis.
Plan
A.General interventions: Discontinue any suspected drug agent.
B. 
See Section III: Patient Teaching Guide Lichen Planus.
1.Instruct patients that the disease may be chronic; most cases resolve spontaneously.
2.Encourage the patient to avoid severe emotional stress.
3.Encourage the patient to avoid scratching and prevent secondary infection.
4.Reassure the patient that lichen planus is not contagious.
C.Pharmaceutical therapy:
1.Oral antihistamines to assist with pruritus: Hydroxy zine hydrochloride 10 to 50 mg four times daily as needed for pruritus, or cetirizine Hcl (Zyrtec) 10 mg daily.
2.Medium- to high-potency topical corticosteroids:
a.Mouth lesions: Fluocinonide 0.05%, ointment or gel, two or three times daily.
b.Body lesions: Betamethasone dipropionate (Diprolene) 0.05%, triamcinolone (Kenalog) or other class 1 cream or ointment, two times daily. Caution patients about steroid atrophy.
c.Genital lesions: Desonide cream 0.05% twice daily initially, although higher-potency creams may be necessary. Topical corticosteroids should be used on genitalia in short bursts only.
d.Hypertrophic lesions: Intralesional injections, such as injecting triamcinolone 2.5 to 10 mg/mL, 0.5 to 1 mL per 2-cm lesion, are helpful for pruritus relief. Use cautiously in dark-skinned patients because of risk of hypopigmentation. Limit the total dose to no more than 40 mg per treatment session. Injections may be repeated after 4 to 6 weeks.
3.Oral prednisone is rarely used, but if necessary use with a short course only and taper.
Follow-Up
A.See the patient in 1 week for evaluation of treatment.
Consultation/Referral
A.Refer the patient to a dermatologist if there is no response to initial treatment.
Individual Considerations
A.Pregnancy: Use caution with medications prescribed.
B.Geriatric red flags:
1.Avoid first-generation anticholinergics because of risk of confusion, dry mouth, constipation, and other anti-cholinergic effects or toxicity.