Scrub typhus is becoming a clinically important cause of acute undifferentiated febrile illness in Taiwan. The incubation period is between 6 and 21 days after exposure. It is transmitted by chiggers (larva of trombiculid mite) in long grasses and in dirt-floor homes, with infection characterized by a flu-like illness of fever, headache, and myalgia lasting approximately 1 week. It has various systemic manifestations, including GI symptoms. In some, the illness progresses to multiorgan dysfunction syndrome and death. We report on a 13-year-old boy who lived in Taipei City and who had initially tentative diagnosis of acute pyrexia of unknown origin with high fever up to 40.3°C for 1 week, but later had thrombocytopenia and diffuse abdominal pain with peritoneal sign suspected acute appendicitis. During the clinical course, septic shock and disseminated intravascular coagulopathy (DIC) were noted. There were skin rash in his trunk and extremities and an eschar with black crust surrounded by a scaling erythematous rim on his right buttock. In addition, we got the information of his travel history in Green Island and Orchid Island for 10 days.With the correct antibiotics, vancomycin, meropenem, and doxycycline, the patient was getting better and corresponding with high level of granulysin and tumor necrosis factor-alpha. The diagnosis of scrub typhus was confirmed by the biopsy of eschar and high quantitative real-time polymerase chain reaction values of Orientia tsutsugamushi (16sRNA and 56 kDa) tested by Centers for Disease Control and Prevention, Taiwan. Histopathological findings of the eschar revealed the leukocytoclastic vasculitis, crust and thrombus formation with many gram-negative microorganisms, O. tsutsugamushi demonstrated by 47 kDa monoclonal antibody immunohistochemical stain and electromicroscopy.
Outcomes: After the careful selection of appropriate antibiotics including meropenem, vancomycin, and doxycycline, he recovered and was subsequently discharged 7 days after admission.
Lesson subsections: This case highlights that scrub typhus infection can mimic acute abdomen and septic shock with DIC. This rare presentation of acute abdomen and septic shock with thrombocytopenia and DIC caused by scrub typhus should remind physicians to be alert to the possibility of acute abdomen and febrile illness resulting from scrub typhus.