How to differentiate and treat lichen planus of the face versus leprosy of the face?

Differentiating Lichen Planus from Leprosy on the Face

Lichen planus of the face presents as violaceous, polygonal, flat-topped papules with fine white Wickham striae, while leprosy presents with hypopigmented or erythematous patches with sensory loss—the key distinguishing feature is that leprosy causes anesthesia in affected areas, which lichen planus never does.

Clinical Differentiation

Lichen Planus Facial Features

• Morphology: Violaceous, polygonal, flat-topped papules and plaques covered with fine white lines (Wickham striae) 1
• Distribution: Can affect face, though less common than flexor surfaces; may involve oral mucosa simultaneously 2
• Sensation: Normal sensation preserved—pruritus is typically present 1
• Surface: Lacy, reticular white lines (Wickham striae) are pathognomonic 3, 1
• Chronicity: In chronic cases, lesions become hyperkeratotic and plaque-like 1

Leprosy Facial Features (from general medical knowledge)

• Morphology: Hypopigmented or erythematous macules, patches, or plaques; may have nodules in lepromatous form
• Distribution: Often affects cooler areas including face, ears, and extremities
• Sensation: Loss of sensation (anesthesia) in affected patches is pathognomonic—this is the critical distinguishing feature
• Associated findings: Thickened peripheral nerves, madarosis (loss of eyebrows/eyelashes), nasal involvement

Diagnostic Approach

Clinical Examination Priorities

• Test sensation carefully in all facial lesions using light touch and pinprick—sensory loss confirms leprosy, not lichen planus 1
• Examine for Wickham striae using tangential lighting or dermoscopy—their presence strongly suggests lichen planus 3, 1
• Check oral mucosa: Oral involvement is common in lichen planus (white lacy patterns or erosions) but not typical in leprosy 4, 5
• Palpate peripheral nerves: Thickened nerves suggest leprosy, not seen in lichen planus

Confirmatory Testing

• Biopsy is mandatory for both conditions before initiating treatment 4
• Lichen planus histology: Lichenoid interface dermatitis with band-like lymphocytic infiltrate at dermoepidermal junction 5, 6
• Leprosy histology: Granulomas with acid-fast bacilli (paucibacillary) or foamy macrophages (multibacillary); slit-skin smear for acid-fast bacilli

Treatment Approaches

Lichen Planus of Face

First-line therapy: High-potency topical corticosteroids (clobetasol 0.05% or fluocinonide 0.05%) 3, 4, 2

• Use cream or ointment formulation for facial skin 3
• Continue until symptoms improve to Grade 1, then taper over 3 weeks 4

Alternative first-line: Tacrolimus 0.1% ointment for all grades 3, 4

Second-line for moderate-severe disease:

• Oral antihistamines for pruritus 4
• Systemic corticosteroids (prednisone) for severe cases 3, 4, 2
• Narrow-band UVB phototherapy if available 3, 4

Refractory disease: Referral to dermatology for systemic immunosuppressants (azathioprine, cyclosporine, hydroxychloroquine, methotrexate, mycophenolate mofetil) or acitretin 3, 2

Leprosy of Face (from general medical knowledge)

• Multidrug therapy (MDT) is standard: rifampicin, dapsone, and clofazimine for multibacillary; rifampicin and dapsone for paucibacillary
• Duration: 12 months for multibacillary, 6 months for paucibacillary
• Requires infectious disease or dermatology consultation

Critical Pitfalls to Avoid

• Never assume lichen planus without testing sensation—missing leprosy has serious public health and treatment implications
• Do not start immunosuppression without biopsy confirmation—this would be catastrophic if the diagnosis is actually leprosy 4
• Remember lichen planus can coexist with oral involvement—examine the mouth in all suspected facial lichen planus cases 4, 5
• Lichen planus is a potentially malignant disorder—long-term follow-up is required to monitor for malignant transformation, particularly in oral/mucosal variants 5