Differential Diagnosis

The patient presents with severe pain and swelling in the right ankle, low-grade fever, recurrent pedal edema, insomnia, and frequent voiding episodes. The following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Gout: The patient's history of recurrent ankle pain and swelling, especially with the involvement of the big toe (podagra), is highly suggestive of gout. The presence of hyperuricemia (indicated by the elevated creatinine and uric acid levels, although not directly measured) and the patient's response to Diclofenac and Mefenamic Acid also support this diagnosis. The recent onset of insomnia and frequent voiding episodes could be related to the pain and discomfort or possibly to the side effects of medications.

• Other Likely Diagnoses

  • Chronic Kidney Disease (CKD): The patient's elevated BUN and creatinine levels, along with the presence of hyperkalemia (K 5.2), hyperphosphatemia (Phos 6.5), and metabolic acidosis (low HCO3), suggest impaired renal function. The urinalysis showing hematuria and proteinuria further supports CKD.
  • Hypertension: The patient has a history of hypertension, and the current blood pressure reading is elevated (160/90). Uncontrolled hypertension can lead to target organ damage, including the kidneys, which might explain the CKD findings.
  • Heart Failure: The presence of cardiomegaly on the chest X-ray, engorged neck veins, and coarse crackles on lung examination suggest heart failure. The patient's history of hypertension is a significant risk factor for heart failure.

• Do Not Miss Diagnoses

  • Sepsis: Although the patient does not have a clear source of infection, the presence of fever, tachycardia, and elevated white blood cell count could indicate a systemic infection. Sepsis is a life-threatening condition that requires prompt recognition and treatment.
  • Cellulitis or Osteomyelitis: The swelling, erythema, warmth, and tenderness of the right ankle could be indicative of a soft tissue infection (cellulitis) or bone infection (osteomyelitis), especially given the patient's history of recurrent infections and the presence of fever.

• Rare Diagnoses

  • Pseudogout (Calcium Pyrophosphate Deposition Disease, CPPD): This condition can present similarly to gout, with acute inflammatory arthritis, but is caused by the deposition of calcium pyrophosphate dihydrate crystals within the joint. It is less common than gout but should be considered in the differential diagnosis, especially if the patient does not respond to typical gout treatment.
  • Amyloidosis: This rare condition involves the deposition of abnormal proteins (amyloid) in various tissues and organs, which can lead to a wide range of symptoms, including renal failure, heart failure, and neuropathy. The patient's long-standing hypertension, CKD, and heart failure could be related to amyloidosis, although it is a less likely diagnosis without more specific findings.