A 19-year-old man consults for a 24-hour history of pain, swelling and functional impotence of the right knee accompanied by a fever of 38°C. Physical examination reveals inflammatory signs and joint effusion in the right knee. Laboratory tests showed leukocytosis with neutrophilia and elevated C-reactive protein. The syndromic diagnosis of acute monoarthritis is made. What is the most likely etiologic diagnosis?
Acute monoarthritis associated with fever, leukocytosis with neutrophilia and increased acute phase reactants does not always have a septic origin. In the absence of further information (more complete anamnesis on the current disease, risk factors, personal and family history, extra-articular symptoms or signs, etc.) it can be said that also 1 and 2 (and very exceptionally 5) could debut with a similar clinical and biological picture. With the data provided and taking into account that this is a young male, the most likely option would be bacterial infectious arthritis (that caused by mycobacteria usually have a chronic course). And above all, because of its implications, the first one to always rule out.
Arthritis due to microcrystals.
Reactive arthritis.
Bacterial infectious arthritis.
Mycobacterial infectious arthritis.
Rheumatoid arthritis.
And above all, because of its implications, the first one to always rule out.
taking into account that this is a young male, the most likely option would be bacterial infectious arthritis
(that caused by mycobacteria usually have a chronic course).