Differential Diagnosis for 81 year old female with fever and burning micturation

• Single most likely diagnosis
  • Urinary Tract Infection (UTI): The patient's symptoms of fever and burning micturation are classic for a UTI, which is a common condition in elderly females, especially with underlying medical conditions like diabetes mellitus (DM) that increase the risk of infection.

• Other Likely diagnoses
  • Pyelonephritis: Given the patient's age and symptoms, pyelonephritis (an infection of the kidney) is a possible diagnosis, especially if the UTI has ascended to the kidneys.
  • Vaginitis: Although less likely than UTI, vaginitis could cause burning sensations and should be considered, especially if there are other symptoms like abnormal vaginal discharge.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sepsis: Any infection in an elderly patient, especially one with multiple comorbidities like hypertension (HTN), DM, and ischemic heart disease (IHD), carries a risk of progressing to sepsis, a life-threatening condition.
  • Kidney Stones with Infection: If the patient has kidney stones and they become infected, it could lead to a severe infection requiring immediate intervention.
  • Prostatitis (less likely in females but could be considered in differential for urinary symptoms): Though prostatitis is more common in males, any condition causing urinary retention or obstruction could potentially lead to similar symptoms and should be considered in a broad differential diagnosis.

• Rare diagnoses
  • Tuberculosis of the Urinary Tract: Although rare, tuberculosis (TB) can affect the urinary tract and cause symptoms similar to those of a UTI, including fever and burning micturation.
  • Interstitial Cystitis: A condition causing bladder pressure, bladder pain, and sometimes pelvic pain, which could be considered if other diagnoses are ruled out and symptoms persist.