[Differential diagnosis of fever after returning from the tropics].

Fever is the cardinal symptom of many infections in travellers returning from the tropics and is second in place only to infectious diarrhea. Once the obvious causes of fever in an individual patient have been eliminated, it may be very difficult to find the cause of fever. Fevers can be distinguished by their length of duration and divided into acute fevers i.e. up to 3 weeks duration and chronic fevers i.e. more than 3 weeks duration. Whether fever goes along with leucopenia or a normal white blood cell count on the one hand or with leucocytosis on the other hand is of differential diagnostic value. A schedule based on these two parameters will be presented to simplify differential diagnostic considerations. Two rules of thumb will be stressed: (1) Each febrile illness, even febrile diarrhea, jaundice or meningitis, is to be considered a malaria until it is excluded. (2) Patients returning from tropical areas might suffer from banal infections such as pneumonia, urinary tract infections, cholangitis, etc. as well.