MRCP2-2715

MRCP2-2715

A 29-year-old construction worker was referred to the hospital by his primary care physician. He had visited the doctor a week ago, complaining of malaise, headache, and myalgia for three days. Despite being prescribed amoxicillin/clavulanic acid, his symptoms persisted and he developed a dry cough and fever. At the time of referral, he was experiencing mild dyspnea, a global headache, myalgia, and arthralgia. Upon examination, he appeared unwell, had a fever of 39°C, and had a maculopapular rash on his upper body. Fine crackles were audible in the left mid-zone of his chest, and mild neck stiffness was noted.

The following investigations were conducted:
– Hb: 84 g/L (130-180)
– WBC: 8 ×109/L (4-11)
– Platelets: 210 ×109/L (150-400)
– Reticulocytes: 8% (0.5-2.4)
– Na: 129 mmol/L (137-144)
– K: 4.2 mmol/L (3.5-4.9)
– Urea: 5.0 mmol/L (2.5-7.5)
– Creatinine: 110 µmol/L (60-110)
– Bilirubin: 27 µmol/L (1-22)
– Alk phos: 130 U/L (45-105)
– AST: 54 U/L (1-31)
– GGT: 48 IU/L (<50) Additionally, a chest x-ray revealed patchy consolidation in both mid-zones. What is the most likely cause of his symptoms?