A febrile patient with a history of diabetes presents with a painful and swollen lower extremity. What is the likely diagnosis?

In this scenario, the patient has a fever, a history of diabetes, and presents with a painful and swollen lower extremity. The combination of these factors suggests an infection as the underlying cause of the symptoms.

Cellulitis is a common bacterial skin infection that typically occurs in patients with a compromised immune system, such as those with diabetes. The condition presents with signs of inflammation, including redness, heat, swelling, and pain, which align with the patient's symptoms. Furthermore, fever often accompanies cellulitis due to the body's systemic response to infection.

While deep vein thrombosis can also cause swelling and pain in the lower extremity, it usually does not present with fever unless there is an associated inflammatory process. Necrotizing fasciitis would indeed present with severe pain and systemic signs of infection, but it typically occurs in the context of a rapidly progressing soft tissue infection and may show signs of necrosis. An abscess could also cause localized swelling and pain and may be associated with fever, but the more generalized presentation without localized fluctuation or a definite pus collection leans more towards cellulitis.

Overall, given the febrile state and the diabetic history, cellulitis is the most likely diagnosis, as it aligns well with the clinical presentation and