A case of lower limb ulcer caused by hydroxyurea in treating primary thrombocytosis.

Hydroxyuria is a common medication for treating blood system diseases, but ulcers in the lower limbs caused by this medication are often rare and not often suspected. We reported an elderly patient with lower limb ulcers caused by hydroxyurea treatment for primary thrombocytosis. When hydroxide is used, close observation of skin lesions and prompt handling of any skin disruption should prevent ulcers.