Oral ulcers caused by hydroxyurea.

We present a case of oral ulceration in a patient with essential thrombocythaemia, that proved to be secondary to treatment with hydroxyurea. This complication has not yet been reported in the ENT literature. Hydroxyurea should be considered as a possible cause of persistent oral ulceration in patients with haematological conditions. It should be noted that the onset of this complication is not related to the dose and duration of therapy.