Differential Diagnosis for Upper GI Bleed with Fever of Unknown Origin and Altered Mental Status

Single Most Likely Diagnosis

• Upper GI Bleed due to Peptic Ulcer Disease with Sepsis: This is a common cause of upper GI bleed and can lead to sepsis, which can cause fever and altered mental status due to the systemic inflammatory response.

Other Likely Diagnoses

• Variceal Bleeding with Spontaneous Bacterial Peritonitis: Patients with cirrhosis can develop variceal bleeding and spontaneous bacterial peritonitis, leading to fever and altered mental status.
• Gastrointestinal Infection (e.g., Salmonella, E. coli): Certain gastrointestinal infections can cause upper GI bleeding, fever, and altered mental status, especially in immunocompromised patients.
• Inflammatory Bowel Disease (IBD) with Toxic Megacolon: IBD can cause upper GI bleeding, fever, and altered mental status if it progresses to toxic megacolon.

Do Not Miss Diagnoses

• Aortic Enteric Fistula: Although rare, this condition can cause catastrophic upper GI bleeding and is often associated with fever and altered mental status due to sepsis.
• Malignancy (e.g., Gastric Cancer): Certain malignancies can cause upper GI bleeding, fever, and altered mental status, and it is crucial to rule out cancer in patients with these symptoms.
• Ischemic Bowel Disease: Ischemic bowel disease can cause upper GI bleeding, fever, and altered mental status, and prompt diagnosis is essential to prevent further complications.

Rare Diagnoses

• Dieulafoy's Lesion: A rare cause of upper GI bleeding, Dieulafoy's lesion is a small, superficial ulceration with a large underlying artery that can cause significant bleeding.
• Hemobilia: Bleeding from the biliary tree can cause upper GI bleeding, fever, and altered mental status, although it is a rare condition.
• Vasculitis (e.g., Henoch-Schönlein Purpura): Certain types of vasculitis can cause upper GI bleeding, fever, and altered mental status, although they are relatively rare.