How to diagnose and treat lichen planus?

Diagnosis and Treatment of Lichen Planus

For diagnosing and treating lichen planus, topical high-potency corticosteroids like clobetasol propionate 0.05% applied twice daily for 2-3 months is the first-line therapy for all forms, including cutaneous, genital, and mucosal erosive lesions. 1, 2

Diagnosis

Clinical Presentation

• Classic cutaneous lichen planus: "Six P's" - planar (flat-topped), purple, polygonal, pruritic papules and plaques 2
• Characteristic Wickham striae - lacy, reticular white lines on the surface of lesions 2, 3
• Common locations:
  • Flexor surfaces of wrists, forearms, and legs 2
  • Oral mucosa - white, lacy patterns or erosive lesions 4
  • Genital mucosa - often painful erosions 2
  • Scalp - can cause scarring alopecia 5
  • Nails - thinning, ridging, pterygium formation 5, 6

Diagnostic Approach

• Classic cases may be diagnosed clinically based on characteristic appearance 2
• Biopsy (4-mm punch) is recommended when:
  • Atypical features or diagnostic uncertainty exists
  • Suspicion of neoplastic change (persistent hyperkeratosis, erosion, erythema)
  • Disease fails to respond to adequate treatment
  • Extragenital lesions with features suggesting overlap with morphoea
  • Pigmented areas to exclude abnormal melanocytic proliferation
  • Before initiating second-line therapy 1

Treatment Algorithm

First-Line Treatment

1. Cutaneous lichen planus:

   • High-potency topical corticosteroids (clobetasol propionate 0.05%) twice daily for 2-3 months 1, 2
   • Gradually decrease dose if symptoms improve 1
   • Advise patients on proper hand washing after application to avoid spreading medication to sensitive areas 1

2. Oral/mucosal lichen planus:

   • High-potency topical corticosteroids as first-line therapy 2, 4
   • Apply directly to affected areas 2-3 times daily

3. Genital lichen planus:

   • Topical clobetasol propionate 0.05% twice daily 1, 2
   • Topical tacrolimus is also effective for vulvovaginal lichen planus 2

4. Nail lichen planus:

   • Intralesional or intramuscular triamcinolone acetonide as first-line therapy 5
   • Topical treatments have poor short-term efficacy 5

Second-Line Treatment

For severe, widespread, or treatment-resistant cases:

• Systemic corticosteroids for severe disease involving multiple sites 2
• Oral retinoids (acitretin) - expensive with significant toxicity profile 2, 5
• Immunosuppressants for resistant cases 2

Follow-up and Monitoring

• Regular long-term follow-up is essential, particularly for genital lesions 7
• Monitor for:
  • Treatment response - if inadequate, consider biopsy and alternative therapies 1
  • Malignant transformation - approximately 4-5% of patients with genital lichen sclerosus develop squamous cell carcinoma 7
  • Warning signs requiring biopsy: persistent hyperkeratosis, erosion, erythema, new warty or papular lesions 1, 7

Prognosis

• Cutaneous lichen planus may resolve spontaneously within 1-2 years, though recurrences are common 2
• Mucosal forms tend to be more persistent and resistant to treatment 2
• Nail involvement may lead to permanent destruction with functional consequences 5

Important Considerations

• Biopsy is crucial when clinical features are atypical or when there's suspicion of malignant transformation 1, 7
• Genital lichen planus/sclerosus carries a 4-5% lifetime risk of developing squamous cell carcinoma, requiring vigilant monitoring 7
• No increased risk of malignancy has been documented in extragenital lichen planus 7