When assessing a patient with acute monoarthritis, which condition must be ruled out?

When evaluating a patient with acute monoarthritis, ruling out septic arthritis is crucial due to the potential for significant morbidity and mortality associated with this condition. Septic arthritis occurs when bacteria invade a joint, leading to inflammation, pain, and potentially irreversible joint damage if not treated promptly.

The clinical presentation often includes a swollen, red, and warm joint, along with systemic symptoms such as fever. An early diagnosis is vital, and this typically involves joint aspiration to analyze synovial fluid for the presence of pathogens and other inflammatory markers. Timely management with antibiotics and possibly surgical intervention to drain the infected joint can prevent serious complications.

While conditions like rheumatoid arthritis, gout, and pseudogout can cause acute joint pain and swelling, these tend to have different presentations and management pathways. In contrast, septic arthritis requires immediate attention to ensure the best possible outcome for the patient. Therefore, among the conditions listed, septic arthritis stands out as the one that must be urgently ruled out in cases of acute monoarthritis.