MRCP2-2867

MRCP2-2867

A 32-year-old man presents to the emergency department with a three-day history of fever, muscle ache, retro-orbital headache, and a rash. He recently returned from a trip to Honduras. He has no significant medical history and takes no regular medications.

Observations:
Heart rate: 101 beats/min
Oxygen saturations: 97% on room air
Respiratory rate: 20 breaths/min
Temperature: 38.5ºC
Blood pressure: 124/82 mmHg

On examination, the patient’s face appears flushed, and he has a maculopapular rash covering most of his body. There is no splenomegaly or synovitis.

Blood tests:
Hb: 121 g/L (Male: 135-180, Female: 115-160)
Platelets: 89 * 109/L (150-400)
WBC: 4.4 * 109/L (4.0-11.0)
Na+: 137 mmol/L (135-145)
K+: 4.2 mmol/L (3.5-5.0)
Urea: 5.2 mmol/L (2.0-7.0)
Creatinine: 88 µmol/L (55-120)
CRP: 22 mg/L (<5)
Bilirubin: 14 µmol/L (3-17)
ALP: 111 u/L (30-100)
ALT: 143 u/L (3-40)
Albumin: 34 g/L (35-50)

What is the most likely diagnosis?