RESUMEN
This report outlines the case of a 51-year-old female patient who had suffered from onycholysis of the thumbs for eight years. The patient complained of experiencing pain when she works in contact with water, affecting her quality of life. Before coming to our clinic, the patient was diagnosed and treated at three dermatology clinics. However, treatment proved ineffective and the cause was not elucidated. As the patient experienced symptoms of onycholysis and dry skin, we diagnosed her with ketsu deficiency and treated her with shimotsuto. The symptoms gradually improved with continuous oral administration, and were no longer present at eight months following the start of treatment. This case suggests that shimotsuto may be effective in treating instances of onycholysis where the cause is unknown.