What is the appropriate workup and treatment for a teenage male with concerns about his height?

Height Workup for a Teenage Male

Begin by plotting height and weight on CDC 2000 growth charts and calculating growth velocity over the past 6 months—if height is below the 3rd percentile or growth velocity falls below the 25th percentile, proceed with comprehensive laboratory and radiographic evaluation. 1

Initial Assessment and Growth Monitoring

• Measure height every 3-6 months using a wall-mounted stadiometer with the patient standing, and plot serial measurements on CDC 2000 growth charts to calculate growth velocity. 2, 1
• Obtain a bone age radiograph of the left wrist to determine remaining growth potential and predict adult height. 2, 1
• Calculate mid-parental target height using Tanner's formula: (mother's height + father's height + 13 cm) ÷ 2, to determine if current trajectory will reach genetic potential. 2, 1
• Assess pubertal status using Tanner staging, as delayed puberty may indicate constitutional delay of growth and puberty. 2, 1

Core Laboratory Evaluation

Order the following tests to identify treatable endocrinopathies and systemic diseases:

• Thyroid function testing (TSH, free T4) to identify hypothyroidism as a reversible cause of growth failure. 1, 3
• Celiac disease screening (tissue transglutaminase IgA with total IgA) as it can present with isolated short stature. 1
• Complete blood count to screen for chronic anemia indicating inflammatory bowel disease or nutritional deficiency. 1, 3
• Comprehensive metabolic panel including serum creatinine, calcium, phosphate, and alkaline phosphatase to screen for chronic kidney disease, metabolic bone disease, or electrolyte disturbances. 2, 3
• IGF-1 and IGFBP-3 levels to assess for growth hormone deficiency or resistance. 1

Nutritional Assessment

• Obtain albumin, prealbumin, vitamin D, vitamin B12, folate, iron studies, and zinc levels to identify nutritional deficiencies that impair growth. 1, 4
• Assess caloric intake and calculate target calories for age, as inadequate nutrition is a readily reversible cause of growth failure. 1
• Supplement identified deficiencies (vitamin D, iron, zinc) which directly impair linear growth. 1

Genetic and Syndromic Evaluation

If height is more than 3 standard deviations below the mean or there are dysmorphic features:

• Obtain karyotype or chromosomal microarray in males with severe short stature to rule out chromosomal abnormalities (though Turner syndrome is specific to females, other chromosomal disorders can affect males). 1
• Order SHOX gene testing if there are subtle skeletal findings such as short forearms, Madelung deformity, or family history of short stature, as mutations occur in 1-12% of idiopathic short stature. 1
• Perform skeletal survey if body proportions appear disproportionate to evaluate for skeletal dysplasia. 1

Growth Hormone Testing

If growth velocity remains below the 25th percentile despite normal screening tests:

• Perform growth hormone stimulation testing to exclude growth hormone deficiency (peak GH <5-10 mcg/L defines deficiency). 1
• Growth hormone deficiency requires specialized endocrine evaluation and is best managed by pediatric endocrinology. 1

Criteria for Specialist Referral

Refer to pediatric endocrinology if:

• Growth velocity deceleration below the 25th percentile persists over 6 months. 1
• Height is more than 3 standard deviations below the mean for age. 1
• Dysmorphic features are present requiring genetics evaluation. 1
• Growth hormone deficiency is confirmed on stimulation testing. 1

Common Pitfalls to Avoid

• Do not dismiss normal variants (constitutional delay, familial short stature) without documenting stable growth velocity within the 25th percentile over at least 6 months. 1
• Do not overlook nutritional deficiencies—these are readily treatable causes of growth impairment that should be addressed before considering growth hormone therapy. 1
• Do not delay evaluation of declining growth velocity, as progressive deceleration suggests pathology requiring prompt investigation. 1
• Do not skip bone age assessment—this is essential for predicting adult height and determining remaining growth potential. 2, 1
• Do not assume eating disorders are absent in males with growth failure—plot BMI and assess for high-risk eating behaviors including severe dietary restriction, excessive exercise, and social isolation. 2

Treatment Considerations if Pathology is Identified

If growth hormone deficiency is confirmed:

• Initiate recombinant growth hormone (somatropin) at 0.18-0.3 mg/kg/week divided into daily subcutaneous injections for pediatric growth hormone deficiency. 5
• Monitor height velocity every 3-6 months and repeat bone age annually to track response. 1
• Discontinue growth hormone once epiphyseal fusion has occurred. 5

If chronic kidney disease is identified:

• Address CKD-associated growth-limiting factors including protein-calorie malnutrition, metabolic acidosis, electrolyte disturbances, and mineral dysregulation before considering growth hormone therapy. 2
• Growth hormone can be initiated in children with stage 3-5 CKD if height is below the 3rd percentile and growth velocity is below the 25th percentile after optimizing metabolic factors. 2