Hydroxyurea as a Cause of Drug Fever

We report on a patient with essential thrombocythemia treated with hydroxyurea who became febrile 3 weeks after the treatment was started. After drug withdrawal, the fever resolved but after rechallenge there was recurrence of the fever. Although hydroxyureainduced fever is rare, this drug must be added to the list of drugs that produce fever and the physicians should be aware of this possibility.