Rocky Mountain spotted fever in pregnancy: differential diagnosis and treatment.

Rocky Mountain spotted fever (RMSF) presents both diagnostic and therapeutic difficulties in the pregnant patient. Early clinical manifestations may be mistaken for normal pregnancy changes. Accurate diagnosis is essential, since several of the disorders in the differential diagnosis may have important obstetric implications. Antibiotics generally used to treat serious infections during pregnancy are ineffective in treating RMSF. Chloramphenicol is the antibiotic of choice. Specific recommendations for evaluating pregnant patients with suspected RMSF are given.