Differential Diagnosis

The patient presents with elevated parathyroid hormone (PTH) levels, cirrhosis, cellulitis, and various laboratory abnormalities. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Sepsis: The patient's elevated CRP (241), presence of cellulitis, and cirrhosis suggest a high likelihood of sepsis, which can lead to multi-organ dysfunction and elevated PTH levels due to systemic inflammation and potential renal impairment.

• Other Likely Diagnoses

  • Hypervitaminosis D: Although less likely, given the context, hypervitaminosis D could lead to elevated PTH levels. However, this would typically be associated with hypercalcemia, which is not mentioned.
  • Chronic Kidney Disease (CKD): The patient's elevated creatinine (SCr 60) suggests impaired renal function, which can lead to secondary hyperparathyroidism. The presence of cirrhosis and potential sepsis complicates the interpretation but makes CKD a plausible consideration.
  • Rhabdomyolysis: The significantly elevated creatinine kinase (741) is indicative of muscle damage, which could be due to rhabdomyolysis. This condition can lead to renal failure and potentially affect PTH levels.

• Do Not Miss Diagnoses

  • Malignancy: Although not directly suggested by the information provided, malignancy can cause elevated PTH levels (either primary through a parathyroid tumor or secondary through malignancy-related hypercalcemia) and should be considered, especially in a patient with cirrhosis who may have an increased risk of hepatocellular carcinoma.
  • Adrenal Insufficiency: In critically ill patients, especially those with sepsis and cirrhosis, adrenal insufficiency can occur and may present with non-specific symptoms. It's crucial to consider this diagnosis due to its high mortality if untreated.

• Rare Diagnoses

  • Familial Hypocalciuric Hypercalcemia (FHH): A rare genetic disorder that could lead to elevated PTH levels. However, it's less likely given the patient's acute presentation and other comorbidities.
  • Parathyroid Carcinoma: A rare cause of primary hyperparathyroidism, which could explain the elevated PTH level but would be unusual without other suggestive symptoms like a palpable neck mass or more significantly elevated calcium levels.