Differential Diagnosis for Increasing Ammonia in a Patient without Cirrhosis or Alcohol Use

• Single most likely diagnosis:
  • Urea cycle disorders: These are genetic disorders that affect the body's ability to remove ammonia from the blood. They are a common cause of elevated ammonia levels in patients without liver disease or alcohol use.
• Other Likely diagnoses:
  • Medication-induced hyperammonemia: Certain medications, such as valproic acid, can cause elevated ammonia levels.
  • Inborn errors of metabolism: Disorders such as organic acidemias and fatty acid oxidation disorders can lead to increased ammonia production.
  • Renal failure: Kidney dysfunction can impair the excretion of ammonia, leading to elevated levels.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Gastric bleeding or intestinal obstruction: These conditions can lead to increased ammonia production and absorption from the gut.
  • Malignancy: Certain types of cancer, such as leukemia or lymphoma, can cause elevated ammonia levels.
  • Sepsis: Severe infections can lead to increased ammonia production and impaired clearance.
• Rare diagnoses:
  • Reye's syndrome: A rare condition that causes mitochondrial dysfunction and can lead to elevated ammonia levels.
  • Hyperinsulinism-hyperammonemia syndrome: A rare genetic disorder that affects insulin and ammonia metabolism.
  • Lysinuric protein intolerance: A rare genetic disorder that affects amino acid transport and can lead to elevated ammonia levels.