12th January 2024

A 48-year-old gentleman presents with progressive shortness of breath on exertion and dry cough.

A 48-year-old gentleman presents with progressive shortness of breath on exertion and dry cough. He has a background of HIV and is known to be poorly compliant with his antiretrovirals. A chest X-ray is taken, which is reported as normal. His oxygen saturations at rest on room air are 94%. You repeat these while the patient is mobilising, and the saturations reduce to 83%. What is the most likely diagnosis?

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