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 (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.