Boutonneuse Fever

A 42-year-old woman returned from a 2-month stay in India with a rash and a low-grade fever. She also complained of fatigue, nausea, anorexia, and weight loss. Despite treatment with amoxicillin for a presumed streptococcal rash, her symptoms worsened. The pruritic rash spread over the patient’s body; only the face was spared.

A complete blood cell count was normal. Hemoglobin level was 11 g/dL. Liver function tests revealed elevated levels of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase; none were more than double the normal values. Acute and later convalescent sera were sent to the CDC for confirmation of suspected rickettsial disease. The results of indirect immunofluorescence assay showed a greater than 4-fold increase in Rickettsia conorii and Rickettsia rickettsii IgG antibody titers, which confirmed the diagnosis of boutonneuse fever (Mediterranean spotted fever).

Initial treatment with levofloxacin caused nausea and emesis, and doxycycline was substituted. The patient's symptoms resolved completely.

Boutonneuse fever and Rocky Mountain spotted fever share the same antigens, and both diseases are transmitted by ticks. This patient may have been bitten while she was staying in a hut in the mountains of India. Among certain untreated patients with rickettsial disease, mortality can be as high as 30%.¹

The take-home message: not all generalized rashes accompanied by fever represent streptococcal infection. Always inquire about recent travel.

REFERENCE:
1. Center for Disease Control and Prevention. Fatal cases of Rocky Mountain spotted fever in family clusters— three states, 2003. MMWR. 2004;53(RR-19):407-410.

FOR MORE INFORMATION:
•Palau LA, Pankey GA. Mediterranean spotted fever in travelers from the United States. J Travel Med. 1997;4:179-182.

(Case and photograph courtesy of Paul Stebbins, MD, of Audubon, Iowa.)