An Unholy Alliance: “Spotless” Rocky Mountain Spotted Fever and Shigella sonnei Bacteremia
Bacteremia complicating Shigella infection is uncommon as is Rocky Mountain spotted fever (RMSF) without a rash. A 27-year-old previously healthy MSM presented with a 4-day history of watery stool, abdominal cramps, nausea and vomiting, and yellow skin and finger tips of 2 days duration. He reported a self-limited diarrhea illness in two close contacts in preceding days. No tick exposure. On examination, he was dehydrated, icteric, febrile and had no rash. Relevant laboratory data included WBC of 2200/µl, elevated AST, ALT (201 IU/L, 73 IU/L respectively), normal alkaline phosphatase, elevated total and direct bilirubin of 8.2 mg/dl and 4.4 mg/dl, albumin of 3.2 g/dl, INR of 2.9, prothrombin time of 31.7 and platelet of 96,000/µl. Work up for infectious, autoimmune and medication-induced hepatitis, Wilson’s disease and hemochromatosis was negative. He tested negative for HIV. CT abdomen and magnetic resonance cholangiopancreatography showed hepatic steatosis, right sided colitis and normal biliary ducts. Rickettsia ricketsii IgM was positive. Stool and blood cultures were positive for Shigella sonnei. He was treated with Doxycycline and Ciprofloxacin with clinical improvement. Follow up blood test 4 months later was within normal limits.
Our patient had Shigella bacteremia and positive Rickettsia ricketsii IgM without a typical rash. Absence of a rash occurs in 10% of cases, delays diagnosis of RMSF and is associated with increased mortality. Rash typically appears in the first five days of illness. Marked hepatic derangement with coagulopathy occurs in advanced RMSF or may have been a sequelae of Shigella bacteremia.
Annual ACP Regional Meeting
Shogbesan, O., & Donato, A. A. (2016). An Unholy Alliance: “Spotless” Rocky Mountain Spotted Fever and Shigella sonnei Bacteremia. Annual ACP Regional Meeting Retrieved from https://scholarcommons.towerhealth.org/gme_int_med_resident_program_read/226