Lichen planus

A mucocutaneous disorder with a prevalence estimated at 0.4-4% in the general population. 

Women account for 60-75% of patients with oral LP and 50% with cutaneous LP.

Mean age at diagnosis:between 50-60 years for oral disease and 40-45 years for cutaneous disease.

Drug-associated OLP, or oral lichenoid drug reactions generally present in the oral cavity as the classic reticular form; however, ulcerated or eroded forms have also been described. 

Less than 5% of cases involve children.

Manifests as papules, or rashes.

Skin involvement characterized by violaceous papules, which may have associated itching.

Cutaneous form generally heals within one year.

Long-standing skin involvement may cause hyperpigmentation, especially in dark skinned individuals.

Oral lesions characterized by white lace like pattern, but may be associated with plaques, papules, erosions, erythematous lesions.

Lichen planus cutaneous lesions are pruritic, violaceous, polygonal papules and often present on the trunk or extremities, although nail, vulvar mucosal, and oral mucosal involvement can be significant.

Oral involvement is chronic and when associated with erosive lesions may be painful.

The skin and oral mucosa are the most frequent sites of involvement.

Other mucous membranes including genitalia, esophagus, and conjunctiva may be involved, as may skin appendages such as scalp, hair, and nails can be affected.

One or multiple areas of involvement can be present, concomitantly or sequentially.

Sometimes associated with certain medications and diseases, but is basically of unknown cause.

Inciting factors include: genetic background, dental materials, drugs, infections of bacterial or viral etiology, autoimmune diseases, diabetes, stress, and hypertension.

The mean age of onset around 50 years, and lichenoid drug eruption median age at onset is around 60 years.

Prevalence of cutaneous LP among men is 0.3% and prevalence of oral LP is 1.5%, while respective prevalence is among women is 0.1% and 2.3% from Swedish data (Hellgren L McCartan BE).

LP is a mucocutaneous disorder with a prevalence estimated between 0.4-4% in the general population.

The association between HCV infection and LP is greater in Europe and Asia than it is in the United States.

In a study of patients who presented with oral lesions prior or current cutaneous involvement, was present in 16% and genital disease in 19%, and in rare involvement of other sites (Eisen D).

Characterized by fine white reticulated pattern, known as Whickham striae.

Six variants of oral lichen planus: reticular, papular, plaque like, atrophic or erythematous, and the erosive forms which are ulcerative or bullous.

These types often coexist in varying combinations.

Idiopathic LP associated with monomorphic, violaceous, shiny papules and plaques, with a fine reticulated pattern of white scale.

Mucous membranes, anterior lower legs and wrists are often affected.

Anogenital involvement clinically similar to cutaneous and oral forms of disease.

Erosive mucosal disease may lead to fibrosis with secondary complications including scarring of nails, scalp, vulva, vaginal stenosis, phimosis, and esophageal strictures.

Associated with lymphocytic infiltrate at the epidermal-dermal junction, damage to the basal layer, colloid bodies,and irregular rete ridges.

Associated with hepatitis C infection.

Lichenoid drug eruption has a latency period of weeks to years, and medications likely alter epidermal proteins acting as haptens inducing an immune response.Lichenoid drug eruption is more polymorphic, and may be more eczematous and scaly than idiopathic variant.

Lichenoid drug eruptionmay have more atypical distribution of lesions than idiopathic LP.

Spontaneous resolution usually occurs within a few weeks of discontinuing associated medications, but it may last as long as 2 to 3 months.

Histopathology reveals a dense lichenoid infiltrate along the dermoepidermal junction and a saw-toothed rete-ridge pattern with Max-Joseph spaces. 

In cases where lesions persist despite treatment, biopsy should be done to rule out displays your or squamous cell carcinoma that may be associated with LP.

1% incidence of squamous cell carcinoma among patients with LP.

Topical corticosteroids primary treatment for oral and cutaneous lesions, and oral corticosteroids reserved for extensive disease requiring symptomatic improvement.

Systemic steroids is the first treatment option for erosive form of oral lichen planus.

Retinoid acitretin is first line nonsteroidal oral therapy.