Patient Education on Lichen Planus

 

 What is Lichen Planus?

 

Lichen planus is a relatively common inflammatory, pruritic (itchy) disease of the skin and mucous membranes. Lichen planus is characterized by distinctive papules which may be as small as a pinhead or larger. The lesions may be flat, polygonal, slightly raised, glistening facets with a violaceous (purple) color and lying between and defined by the natural lines of the skin. The surface is dry and shiny with scanty, adherent scales. The eruption is commonly discrete, but may coalesce to form plaques or annular lesions. With lichen planus, there may be seen toward the center of the papule, an umbilication or a small horny plug at the site of a pore may. Lichen planus commonly involves the volar aspects of the wrists and the medial sides of the thighs, where the lesions tend to be grouped. The shins, backs of the hands and glans penis are also frequently involved. The face is rarely affected, except for the upper eyelids and the vermilion of the lower lip. Mucous membrane involvement is seen in over 50 percent of patients with lichen planus. Wickman's striae of the oral mucosa are thin whitish lines on the surface of the mucosa. The lesions are often on the buccal mucosa and appear as a lacy, white network. Other oral lesions appear as white papules or plaques on the tongue. Nail changes are present in 5 to 10 percent of patients. The nail matrix is replaced by fibrosis. Longitudinal grooving, ridging, splitting, and a peculiar midline fissure are frequent manifestations. The scalp lesions are patches of scarring, atrophic alopecia secondary to inflammatory destruction of the follicles and is called pseudopelade.

What are the symptoms?

Pruritus (itching) is usually a prominent symptom, often occuring in spasms, and causes itching frenzies that can last from minutes to hours, gradually subsiding. Koebner's isomorphic phenomenon (localized spreading of the lesions of lichen planus) is frequently seen in lichen planus due to scratching or rubbing. There are a number of clinical forms of lichen planus. The papular lesions are by far the most common. Small vesicles and bullae may be seen as part of the general papular eruption. Another, but rare manifestation is lichen planus pemphigoides, which shows large bullae (blisters) on normal and involved skin. Lichen planus erythematosus is another unusual form of the disease seen primarily in elderly patients. Soft, nonpruritic, slightly erythematous or pruritic papules usually occur on the forearms. Hypertrophic (thickened) lichen planus may be seen on the lower extremities, especially in Mediterranean regions. Malignant change has been noted in some chronic hypertrophic forms of lichen planus, especially in the ulcerative lesions of the tongue or oral mucosa. If oral lichen planus is severe, Dr. Jacobs may refer the patient to an oral surgeon.

 

What Causes Lichen Planus?

The cause is often unclear. The exclusion of causative drugs and chemicals is essential before making the diagnosis of lichen planus. Some patients complain of emotional stress. The differential diagnosis is long and includes psoriasis, discoid lupus erythematosus, lichen sclerosus et atrophicus, and folliculitis decalvans. When in doubt, a biopsy may help. The histopathology (microscopic features) of lichen planus is diagnostic in the majority of cases. Under the microscope, the epidermis shows what doctors call: hyperkeratosis, a thickened granular layer, patchy acanthosis, and liquefaction  (degeneration) of the basal cell layer of the skin.

 

How is Lichen Planus treated?

Local symptomatic treatment may be achieved with corticosteroid creams, ointments, or sprays, along with colloidal baths. Antihistamines may give relief for itch. It is important to follow the instructions outlined in Dr. Jacobs educational handout on dry and sensitive skin. When there is widespread involvement with limited lesions, intralesional corticosteroid injections may produce prompt involution of the lesions. Hyperkeratotic lesions may respond to topical retinoic acid 0.1% cream base. A course of systemic corticosteroids may induce long term or temporary resolution. Oral lichen planus may respond to topical triamcinolone in Orabase. Oral lichen planus may require surgical excision due to the danger of subsequent development of squamous cell cancer. Dr. Jacobs usually refers oral lichen planus to the oral surgeon for evaluation and regular follow up.

 

What can you expect?

The prognosis of acute lichen planus is good with expected resolution in 6 to 18 months. Relapse does occur, but usually clears again within several months. Chronic cases may persist for more than 15 years. There may be no treatment to shorten the course of the disease. This is especially true of the hypertrophic form, the oral forms of lichen planus, and lichen planopilaris of the scalp. After the lesions have disappeared, deep pigmentation may persist for many months. Less often, depigmented atrophic (thin) spots may remain. There are usually no other systemic complications except the slight danger of development of squamous cell carcinoma in the oral lesions.