ABSTRACT
This chapter presents guidelines to manage the patient coming back from the tropics with an unexplained pyrexia. In areas free of malaria, one must think of the disease in two types of patients: the intravenous drug addicts and the recipients of blood transfusions. The main differential diagnoses includes bacterial liver abscesses, cholecystitis, and hepatic cancers. A prolonged fever may be seen only in lymphatic filariasis. Transmitted by various mosquitoes, it is present in most tropical areas, including the Pacific islands. Central nervous system cysticercosis may be a cause of Unexplained Fever (U.F.). False-positive results may be seen in malaria or trypanosomiasis. An infection due to P. pseudomallei must be considered in any patient who has lived in endemic areas, mainly Southeast Asia. High fever is associated with prostration, diarrhea and/or vomiting and in severe cases hemorrhage and collapse. In contrast, infiltrative pulmonary disease with eosinophilia may present as U.F.
