Unusual cause of recurrent fever after travel in South America

Fever in returning travelers is a common problem and usually the diagnosis is made within a few days or the traveler recovers. We present two travelers who presented with fever two weeks after returning from a six week vacation in South America. Over the following 18 months they presented with short attacks of fever, elevated CRP and leukocytosis and the program for investigation became more and more elaborate. A curious and key feature was, that they were completely synchronous both developing symptoms within an hour and presentation with the same laboratory findings of leukocytosis and elevated CRP. Extensive and repeated tests were performed, at our facility and abroad. After a year it was discovered that the uses of aroma oils were associated with the symptoms. No similar case has been found to be reported previously. These cases emphasize that natural products are not inherently safe. The investigational program was build up over time as new attacks continued to occur and suggestions from different centers which were consulted were followed up. The number of tests performed at different laboratories took an extensive amount of time. These cases emphasize that a panel of analysis in returning travelers in which no clear diagnosis is found should be developed.