Lichen Planus Pigmentosus (LPP)
- An atypical, uncommon macular variant of lichen planus.
- Causes significant cosmetic distress.
- Morphology: Bluish-grey to brownish-black coalescing macules.
- Commonly affects sun-exposed areas.
- Course and Prognosis:
- Unpredictable course: Spontaneous resolution in some, persistent pigmentation in others.
Differential Diagnoses of Lichen Planus Pigmentosus
- Erythema dyschromicum perstans (EDP)/ashy dermatosis (AD)
- Pigmented contact dermatitis (PCD)
- Melasma
- Postchikungunya pigmentation
- Acanthosis nigricans
- Drug-induced pigmentation
- Postinflammatory pigmentation
- Macular amyloidosis
- Nevus of Ota and Hori nevus
Treatment options of Lichen Planus Pigmentosus:
- Topical Treatments:
- Topical mometasone furoate 1% cream
- Tacrolimus cream :
- Topical tacrolimus ointment 0.03% applied twice daily for 6–12 weeks
- Topical tacrolimus 0.1% once or twice daily.
- Topical 5% azelaic acid foam and tretinoin cream with twice-monthly chemical peels using glycolic acid and Jessner’s solution.
- Oral Treatments:
- Low-dose isotretinoin (20 mg/day) for 6 months with broad-spectrum sunscreen.
- Oral tranexamic acid at 250mg daily for 4–6 months.
- Oral vitamin A (100,000 IU daily for 15 days, followed by 15 days without treatment).
- Oral Mini Pulse Therapy with Dexamethasone, 2.5 mg twice weekly.
- Oral colchicine 0.5 mg twice per day for 3 months, tapered for 6 months.
- Dapsone 100mg once daily
- Acitretin 25 mg daily with topical mometasone twice daily.
- Other Treatments:
- Q-switch Nd-YAG laser therapy
- Spot Size: 5 mm
- Fluence: 3–4.6 J/cm²
- Frequency: 5 Hz
- Fluence: Periodically increased during treatment sessions
- Treatment Frequency: Every 4–8 weeks
- Average Number of Sessions: 5-6 sessions.
- Chemical peel with croton oil-free phenol.
- Narrowband ultraviolet B.
- Q-switch Nd-YAG laser therapy
Combination treatment options
- Sunscreen use should be prescibed with any regimen.
- Combiantion between topical and systemic treatments usally used.
Clinical Insights:
- Best outcomes with histopathological diagnosis and depth of pigmentation assessment.
- Disease activity control via topical or oral immunomodulators.
- Refractory hyperpigmentation due to deep dermal melanophages, treated effectively with chemical peels and laser.
References
- Updates In Therapeutics for Lichen Planus Pigmentosus[link]