What is the cause of persistent fever with chills in a 38-year-old male with a history of Double J (ureteric stent) stenting, who has had the stent removed, despite normal laboratory reports and cultures?

Differential Diagnosis for PUO in a 38-year-old Male with History of DJ Stenting

Single Most Likely Diagnosis

• Stent-related infection or biofilm formation: Despite the removal of the DJ stent, the presence of fever and chills suggests that an infection related to the stent might still be present, possibly due to biofilm formation on the stent or a residual infection in the urinary tract.

Other Likely Diagnoses

• Urinary tract infection (UTI): Although cultures are reported as normal, UTIs can sometimes present with negative cultures, especially if the patient has been on antibiotics or if the infection is due to a fastidious organism.
• Bacterial endocarditis: This condition can present with fever and chills and might not always have positive blood cultures initially, especially if the patient has been on antibiotics.
• Intra-abdominal abscess: Given the history of DJ stenting, there's a possibility of an intra-abdominal abscess that might not be immediately apparent on initial imaging or might have developed after the stent removal.

Do Not Miss Diagnoses

• Tuberculosis (TB): TB can present with fever of unknown origin and might not always have typical symptoms or positive cultures initially. It's crucial to consider TB, especially if the patient has risk factors or exposure history.
• Endocarditis due to unusual organisms: Certain bacteria, fungi, or other pathogens can cause endocarditis and might be difficult to culture, requiring special media or techniques.
• HIV or other immunocompromised states: These conditions can predispose to a wide range of infections that might not be immediately apparent or could present atypically.

Rare Diagnoses

• Malakoplakia: A rare inflammatory condition that can affect the urinary tract and present with fever and other systemic symptoms.
• Xanthogranulomatous pyelonephritis: A rare form of chronic pyelonephritis that can present with systemic symptoms like fever and might not always have positive cultures.
• Fungal infections: Certain fungal infections, especially in immunocompromised patients, can present with fever of unknown origin and might require specific diagnostic tests for identification.