What are the next steps for a child with elevated alkaline phosphatase (alk phos) levels?

From the Guidelines

The next steps for a child with elevated alkaline phosphatase levels should include a thorough medical evaluation to determine the underlying cause, starting with a complete medical history, physical examination, and laboratory testing, including liver function tests and bone-specific alkaline phosphatase isoenzymes, as recommended by the most recent guidelines 1.

Key Considerations

• Elevated alkaline phosphatase in children can be normal due to bone growth, with levels typically higher than adult reference ranges, especially during growth spurts.
• A thorough medical evaluation is necessary to determine the underlying cause of elevated alkaline phosphatase levels.
• Laboratory testing should include liver function tests (AST, ALT, bilirubin, GGT), calcium, phosphorus, vitamin D levels, and possibly parathyroid hormone.
• Depending on the clinical picture, additional tests may include bone-specific alkaline phosphatase isoenzymes, X-rays of bones, liver ultrasound, or bone scans.

Potential Underlying Causes

• Bone growth and development
• Liver disease (e.g., cirrhosis, chronic hepatitis, viral hepatitis)
• Bone disorders (e.g., Paget's disease, bony metastases, fracture)
• Other conditions (e.g., hypophosphatasia, X-linked hypophosphatemia)

Management and Treatment

• Treatment will depend entirely on the underlying cause, ranging from simple monitoring for physiologic elevations to specific interventions for liver disease, bone disorders, or other conditions.
• Referral to a pediatric gastroenterologist, endocrinologist, or orthopedist may be necessary if the elevation is significant or accompanied by symptoms.
• Parents should be reassured that isolated alkaline phosphatase elevation in an otherwise healthy, growing child often requires no treatment beyond monitoring, as supported by recent clinical practice recommendations 1.

From the Research

Next Steps for a Child with Elevated Alkaline Phosphatase (Alk Phos) Levels

• The first step is to determine if the elevated alkaline phosphatase level is due to a benign condition or an underlying bone or liver disease 2, 3.
• If the child is otherwise healthy and has no other clinical or laboratory suspicion of bone or liver disease, a "wait and see" approach may be optimal, with a repeat of the alkaline phosphatase level within a few months to confirm resolution of the condition 2, 3.
• It is essential to exclude other known causes of markedly elevated serum alkaline phosphatase, especially bone and liver disease, before considering a benign condition such as transient hyperphosphatasemia 2.
• Elevated alkaline phosphatase levels can also be associated with rickets, a disease of the growing child arising from alterations in calcium and phosphate homeostasis 4, 5.
• A diagnostic workup for rickets includes clinical symptoms, radiological findings, and biochemical analyses, such as serum alkaline phosphatase levels 5.
• Reference intervals for alkaline phosphatase vary with age and gender, and the prevalence of high alkaline phosphatase among healthy children is approximately 2.4% below 5 years of age and 6.2% below 2 years 6.

Possible Causes of Elevated Alkaline Phosphatase

• Benign transient hyperphosphatasemia, a condition characterized by greatly increased serum alkaline phosphatase without laboratory or clinical evidence of underlying bone or liver disease 2, 3.
• Rickets, a disease of the growing child arising from alterations in calcium and phosphate homeostasis 4, 5.
• Other bone or liver diseases, such as vitamin D deficiency or dietary calcium deficiency 4, 5.

Diagnostic Approach

• Clinical evaluation, including medical history and physical examination 2, 3.
• Laboratory tests, such as serum alkaline phosphatase, liver enzymes, calcium, intact PTH, and vitamin D 2, 3, 6.
• Radiological findings, such as X-rays of the wrist or knee, to evaluate for rickets or other bone diseases 5.