Simvastatin ointment in the treatment of seven childhood diffuse plane xanthomas

Diffuse plane xanthomas (DPX) is a rare, chronic, metabolic skin disease which can seriously affect the appearance of the patients and result in psychological problems. Existing treatments are seriously limited. Our objective was to assess the efficacy of and tolerance to simvastatin ointment for the treatment of skin lesions in seven DPX patients. In this study, patients were treated twice daily on the right side of the lesions for 10 months with the 1% or 5% simvastatin ointment. Meanwhile, the left body was untreated as a contralateral controlled side. Efficacy was assessed via the change of rash and was further confirmed by histological study. For all seven participants, both the 1% and 5% simvastatin ointments were effective. The histological change in DPX showed significant decrease of foam cells in skin lesions. The immunohistochemical staining of CD68, macrophage scavenger receptor type 1, oxidized low-density lipoprotein receptor 1 and Oil Red O became obviously reduced after treatment. The test medicines were safe with only some skin-related side-effects. This is the first research reported on simvastatin ointment treatment in DPX. Our results are the first to suggest that simvastatin ointment is effective in improving skin lesions of DPX clinically and histopathologically.