Low‐dose oral isotretinoin therapy in lichen planus pigmentosus: an open‐label non‐randomized prospective pilot study

BACKGROUND: Lichen planus pigmentosus (LPP) is a cosmetically distressing pigmentary disorder often posing a therapeutic challenge. Isotretinoin has been shown to be effective in oral and cutaneous LP, but its role in LPP is yet unknown. OBJECTIVE: To evaluate the efficacy and safety of isotretinoin in the management of LPP. METHODS: In this prospective study, 32 clinically and histologically proven patients with LPP were recruited. Subjects were treated with fixed low-dose (20 mg/day) oral isotretinoin once daily for 6 months along with topical sunscreens. Response was graded as mild (<25%), moderate (26-50%), and good (>50%) improvement based on decrease in intensity and progression of hyperpigmentation. RESULTS: Twenty-seven patients (17 females and 10 males), aged 20-62 years, completed the study. Twenty-three (85.2%) patients had active disease and pruritus at presentation. Treatment outcome was moderate improvement in 15 patients (55.7%) followed by good in seven (21.8%) and mild in two (6.2%). Pruritus subsided at the earliest at 9-14 days, and disease stabilized by 4-6 weeks in treatment-responsive patients. Patients with a shorter duration (≤5 years) of disease and limited body area involvement had a better outcome. CONCLUSIONS: Low-dose isotretinoin seems to be a promising treatment modality in stabilizing and decreasing the pigmentation in LPP particularly in early and limited disease.