Oral and Topical Retinoid Therapy for the Treatment of Lichen Planus Pigmentosus in a 21-year-old Filipino

Lichen planus pigmentosus (LPP) is a rare condition causing dark brown to gray patches, usually appearing on sun-exposed areas such as the face and neck. Various treatment modalities have been reported to be beneficial in stabilizing the disease and improving pigmentation; however, an optimal treatment method is yet to be established. We report a case of a 21-year-old healthy Filipino female, who presented with a 1-year history of multiple grayish-brown macules and patches that were visible on the face, neck, trunk, limbs, and flexures. The patient was started on oral isotretinoin (20 mg/day) and daily application of topical tretinoin 0.05% cream. After 4 months, her condition stabilized with no new lesions, and by the 7 th month, hyperpigmentation reduced significantly. The recalcitrant nature of LPP makes therapy challenging, and there is still no definitive treatment for this condition. In this case, combining oral and topical retinoids worked well for stabilization and pigmentation reduction. However, additional treatments might be needed for more significant skin lightening since retinoids alone may not fully reduce the hyperpigmentation.