Rocky Mountain spotted fever: gastrointestinal and laboratory manifestations.

Sixty-six cases of serologically documented Rocky Mountain spotted fever (RMSF) from North Carolina are reviewed. Gastrointestinal manifestations were present in 80% of these patients. Because other common expressions of RMSF occasionally do not accompany severe gastrointestinal dysfunction, improper diagnosis and therapy can result. Sixty percent of the patients had hyponatremia and thrombocytopenia. Over 70% of those who had liver or muscle enzyme evaluations had at least one abnormality. RMSF should be strongly considered in the differential diagnosis of patients with a combination of these findings.