Lichen Planus

Definition

• Lichen planus is a chronic inflammatory disorder affecting the skin and mucosa, typically seen in adults over 40.

• It is considered autoimmune in nature, possibly triggered by stress, trauma, or certain medications.

• The immune response primarily targets keratinocytes, leading to characteristic lesions.

Clinical Features

• Known by the “5 Ps”:

  1. Polygonal

  2. Pruritic

  3. Purple

  4. Papular

  5. Plaques

• Lesions often show Wickham’s striae (fine white, lacy lines) on the surface.

• Common sites: Wrists, ankles, lower back, and oral mucosa (cheeks, tongue, lips).

• Approximately 1 in 100 people affected, slightly more in middle-aged or older adults.

Types

Cutaneous Lichen Planus

• Shiny, flat-topped polygonal plaques on the skin (wrists, ankles).

• Wickham’s striae on the surface.

• Severe cases can have persistent ulcers or erosions.

Oral Lichen Planus

• Involves cheeks, gums, or lips.

• Painful erosions, redness, Wickham’s striae are common.

• Increased risk of oral squamous cell carcinoma if persistent erosive lesions.

Management

General Measures

• Avoid irritating soaps, minimise friction/trauma to lesions.

• Regular emollients to reduce dryness and itching.

Specific Treatments

• Potent Topical Corticosteroids (e.g. clobetasol propionate) → first-line for localised cutaneous lesions.

• Topical Calcineurin Inhibitors (e.g. tacrolimus ointment) → especially for oral or genital lesions.

• Retinoids (topical or systemic) → help reduce thickness of plaques, can be considered in severe or recalcitrant cases.

• Intralesional Steroids (e.g. triamcinolone) → for persistent plaques or hypertrophic lesions.

Prognosis

• Many cases resolve spontaneously within 6–9 months, but some can become chronic or severe.

• Oral lichen planus may persist longer; regular follow-up is essential to rule out malignant transformation.

• Biopsy if diagnosis is uncertain or if lesions show suspicious changes (to exclude SCC).