Scrub typhus with presentation of acute abdomen

Scrub typhus is a systemic illness with protean clinical manifestations. We encountered two cases of scrub typhus with unusual presentations of acute abdomen. One mimicked acute acalculous cholecystitis while the other simulated uncertain peritonitis. Both patients manifested a high fever, headache, and acute abdominal pain, but neither had eschar on their skin. The first patient presented with sepsis and a positive Murphy's sign, which was misdiagnosed as acute acalculous cholecystitis via abdominal ultrasound. An unnecessary laparotomy was performed as a result. The second patient presented with sepsis and diffuse acute abdominal pain. As the diagnosis of peritonitis was equivocal, a diagnostic laparoscopy was performed to rule out a true surgical abdomen. The clinical manifestations in both cases quickly improved after the administration of minocycline while the definite diagnosis of scrub typhus was later confirmed by a high titer of specific IgM in the acute stage and/or a four-fold increase of IgG against Orientia tsutsugamushi in the serum of convalescent patients as demonstrated by an indirect immunofluorescent antibody test. It is suggested that scrub typhus should be considered in the differential diagnosis of acute abdomen, especially in endemic areas. A diagnostic laparoscopy is highly recommended in any equivocal acute abdomen.