Effects of ısotretinoin on the growth rate and thickness of the nail plate

BACKGROUND Isotretinoin has various effects on nails. However, the mechanism of how isotretinoin affects the nail plate is unknown. We aimed to investigate the effects of isotretinoin on morphology, growth rate, and thickness of the nail plate. METHODS A total of 70 acne vulgaris patients treated with isotretinoin and a control group consisting of 68 healthy volunteers were included in the study. Isotretinoin treatment was started at a dose of 0.5 mg/kg per day. Nail changes were noted; length and thickness of the nail plate were measured in all participants every month. RESULTS The medians of nail growth rates in the isotretinoin and control groups were 3.16 (2.87-3.57) mm/month and 2.89 (2.56-3.19) mm/month, respectively. The medians of nail thickness in the isotretinoin and control groups were 0.47 (0.38-0.53) mm and 0.50 (0.40-0.65) mm, respectively. Statistically significant differences were observed between the groups in terms of nail growth rate and thickness (P < 0.01, P = 0.02, respectively). Nail findings were observed in nine out of 70 patients (12.8%), mostly onychoschizia. CONCLUSION Isotretinoin gradually increases the nail growth rate and thins the nail plate over time during the course of isotretinoin treatment. Dermatologists prescribing isotretinoin should also consider the nail changes, which may impact the life quality of patients.