Differential Diagnosis

• Single most likely diagnosis
  • Congo Crimean hemorrhagic fever: This diagnosis is the most likely due to the combination of symptoms such as high fever, severe headache, chills, body aches, back pain, hemorrhagic rash, and the presence of hemorrhage in the sclera. The patient's residence in the West Kazakhstan region, an area known to be endemic for this disease, further supports this diagnosis.
• Other Likely diagnoses
  • Omsk hemorrhagic fever: Although less common, Omsk hemorrhagic fever could be considered due to the presence of hemorrhagic symptoms and the patient's geographic location. However, the specific constellation of symptoms and the severity of the presentation might lean more towards Congo Crimean hemorrhagic fever.
  • Hemorrhagic fever with renal syndrome: This diagnosis is also plausible given the symptoms of fever, headache, and renal involvement indicated by decreased diuresis and the positive symptom of tapping on the lower back, which could suggest kidney involvement.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
  • Glomerulonephritis: Although less likely given the acute presentation with hemorrhagic symptoms, glomerulonephritis could lead to severe renal complications if not addressed promptly. The presence of decreased diuresis and an enlarged liver might suggest renal involvement, making it crucial not to miss this diagnosis.
  • Pyelonephritis: This condition, an infection of the kidney, could present with fever, back pain, and decreased urine output. While the hemorrhagic symptoms are not typical, the severity of the illness and potential for sepsis make it a diagnosis that should not be overlooked.
• Rare diagnoses
  • Other rare hemorrhagic fevers or viral illnesses could be considered, but given the information provided, they are less likely and would not be the primary focus of the differential diagnosis without additional specific clues or exposures.