Differential Diagnosis for Chronically Elevated Alk Phos with Normal LFTs
Single Most Likely Diagnosis
- Bone-related disorders: Conditions such as Paget's disease, osteomalacia, or hyperparathyroidism can cause elevated alkaline phosphatase (alk phos) levels due to increased bone turnover, without affecting liver function tests (LFTs).
Other Likely Diagnoses
- Vitamin D deficiency: This condition can lead to increased bone turnover and elevated alk phos levels, even in the absence of abnormal LFTs.
- Pregnancy: Alk phos levels can rise during pregnancy due to increased production by the placenta, without indicating liver disease.
- Osteoporosis: While not always associated with elevated alk phos, osteoporosis can lead to increased bone resorption and subsequent elevation in alk phos levels.
Do Not Miss Diagnoses
- Biliary obstruction: Although LFTs may be normal, biliary obstruction (e.g., due to gallstones or a tumor) can cause elevated alk phos levels. Missing this diagnosis could lead to severe consequences, including liver damage or infection.
- Celiac disease: This condition can cause malabsorption of fat-soluble vitamins, leading to elevated alk phos levels due to bone disease, without abnormal LFTs.
Rare Diagnoses
- Hypophosphatasia: A rare genetic disorder characterized by low alkaline phosphatase activity in tissues, but elevated levels in blood due to the body's attempt to compensate.
- Wilson's disease: A genetic disorder that can cause liver disease and elevated alk phos levels, although LFTs may be normal in early stages.
- Fibrous dysplasia: A rare bone disorder that can lead to elevated alk phos levels due to increased bone turnover.