3rd August 2023

A middle-aged relief worker is admitted to the Acute Medicine Unit with undulating fevers for several weeks, which are worse at night.

A middle-aged relief worker is admitted to the Acute Medicine Unit with undulating fevers for several weeks, which are worse at night. He has recently returned from working in Syria on mission outreach projects for several years. On further questioning, he also complains of lethargy, a dry cough with intermittent nosebleeds, and severe stiffness and pain around his lower back and ‘seat bones’. He denies any risky sexual activity and eats well cooked food. He does not smoke or drink much alcohol but admits to enjoying buttermilk on his travels.

Pelvic X-Ray shows periosteal inflammation suggestive of sacroiliitis. Blood tests demonstrate lymphopenia and thrombocytopenia. CXR is unremarkable.

What is the most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.