Abstract
Japanese spotted fever (JSF) is a tick-borne disease caused by Rickettsia japonicaand primarily affects the warmer coastal areas of Japan. Early treatment with tetracycline antibiotics is crucial to prevent severe complications, such as pneumonia, meningitis, disseminated intravascular coagulation (DIC), and systemic inflammatory response syndrome. An 83-year-old man with hypertension, chronic kidney disease, and hyperuricemia presented with DIC and subsequently developed septic shock. Polymerase chain reaction confirmed JSF caused by R. japonica. Initial treatment with ceftriaxone was ineffective, leading to a switch to intravenous minocycline and levofloxacin. Considering the high levels of C-reactive protein, procalcitonin, ferritin, and soluble interleukin-2 receptor, intravenous hydrocortisone (200 mg/day) was administered to control the cytokine storm. On day 4, the patient's condition improved significantly, with increased blood pressure, reduced DIC markers, and decreased levels of inflammatory cytokines, including interleukin-6 and tumor necrosis factor-α. The patient's recovery continued, and he was transferred to a chronic care hospital. Severe JSF cases are primarily driven by a cytokine storm caused by an excessive immune response. Early administration of corticosteroids along with antibiotics effectively suppressed the cytokine storm in this case. Reports have shown mixed results, indicating the need for further research to determine the optimal type, dosage, and duration of corticosteroid treatment.