Background: Hydroxyurea has few side effects excepting the known bone marrow toxicity. Fever with or without pneumonia has occasionally been reported.
Case report: A patient given hydroxyurea for polycythemia suddenly developed severe interstitial pneumonia with fever and hypoxemia. All bacteriological tests were negative and an empirical antibiotic regimen was ineffective. Fever recurred after reintroducing hydroxyurea and definitive cure was achieved after its withdrawal. The clinical course was rapidly favorable without the need for corticosteroids.
Discussion: Fever, and in some cases interstitial pneumonia, in patients given hydroxyurea generally suggests an infection. However, 15 cases of pneumonia have been reported as caused by hydroxyurea in patients treated for a myeloproliferative syndrome. Delay to onset is 3 to 8 weeks after initiating treatment. The course is favorable after withdrawal, with or without corticosteroids. Fever may be the only sign of a drug reaction, resolving with withdrawal and recurring at re-challenge. The underlying mechanism remains unknown. Definitive cure can be achieved by discontinuing hydroxyurea, avoiding the need for further investigations.