How should I evaluate and manage growth failure in a 10‑18‑year‑old adolescent?

Evaluation and Management of Growth Failure in Adolescents (Ages 10-18)

Begin by plotting height on standardized growth charts and calculating height velocity over a minimum 6-month period; adolescents with height >2 SD below the mean (below 3rd percentile) or height velocity below the 25th percentile warrant immediate evaluation for underlying pathology. 1, 2

Initial Clinical Assessment

Growth Parameters to Document

• Serial height measurements plotted on CDC growth charts (for ages ≥2 years) to calculate height standard deviation score (SDS) 1, 2
• Height velocity assessed over 6 months minimum in adolescents to identify progressive growth failure 3, 4
• Mid-parental target height calculated using: For girls: (mother's height + father's height - 13)/2; For boys: (mother's height + father's height + 13)/2 3
• Pubertal staging according to Tanner criteria in all patients ≥10 years: boys assessed by testicular volume via orchidometer (first sign of puberty), girls by breast development (thelarche as first sign) 3, 4

Key Historical Elements

• Timing of growth deceleration using serial heights and photographs to pinpoint onset 3
• Nutritional intake with detailed feeding history, as inadequate caloric intake is the most common cause of growth failure 3, 2
• Systemic symptoms suggesting chronic disease: polyuria, polydipsia (renal disease), chronic diarrhea (malabsorption), headaches or visual changes (intracranial pathology) 3
• Family history of short stature, delayed puberty, or pituitary disorders 3

Physical Examination Findings

• Body proportions to distinguish skeletal dysplasia (disproportionate) from endocrine causes (proportionate) 5
• Dysmorphic features: Turner syndrome stigmata in girls, acromegalic features if GH excess 3
• Signs of chronic disease: pallor, wasting, cushingoid features, goiter 3, 1
• Pubertal delay indicators: boys with testicular volume <4 mL at age 14 years; girls with breast stage <B2 at age 13.5 years require endocrinology referral 3, 4

Essential Laboratory and Radiographic Evaluation

First-Line Testing

• Bone age radiograph (left wrist) to assess growth potential and distinguish familial short stature (normal bone age) from endocrine pathology (delayed bone age) 3, 5
• Serum IGF-1 level matched to age, sex, and Tanner stage as marker of GH status 3
• Thyroid function: TSH and free T3 (hypothyroidism must be corrected before GH therapy can be effective) 3, 6
• Complete metabolic panel: assess renal function (creatinine, eGFR), electrolytes, bicarbonate, calcium, phosphorus 3
• Complete blood count and inflammatory markers to screen for chronic systemic illness 1

Additional Testing When Indicated

• Karyotype in all girls with unexplained short stature to rule out Turner syndrome 7, 1
• Celiac screening (tissue transglutaminase antibodies) if poor weight gain accompanies growth failure 1, 2
• GH stimulation testing if IGF-1 is low and clinical suspicion for GH deficiency is high (requires two provocative tests showing inadequate GH response) 7, 8
• Genetic testing for syndromic causes if dysmorphic features present 3, 1

Management Based on Etiology

Growth Hormone Deficiency

Initiate recombinant GH therapy at 0.045-0.05 mg/kg/day subcutaneous injection in the evening, with dose escalation up to 0.7 mg/kg/week divided daily in pubertal patients. 5, 6, 7

Pre-Treatment Requirements

• Fundoscopic examination to rule out papilledema (GH can worsen intracranial hypertension) 3, 5, 6
• Confirm open epiphyses on bone age radiograph (treatment futile after epiphyseal closure) 3, 5
• Optimize thyroid function first, as hypothyroidism prevents GH efficacy 3, 5

Monitoring During GH Therapy

• Clinical visits every 3-6 months to assess height velocity (should increase ≥2 cm/year above baseline in first year), growth parameters, and pubertal progression 5, 6
• Laboratory monitoring: glucose (for insulin resistance), calcium, phosphorus, PTH, bicarbonate, thyroid function 6
• Adverse effect surveillance: persistent headache/vomiting (intracranial hypertension requiring immediate fundoscopy), lipoatrophy at injection sites (prevented by daily site rotation), slipped capital femoral epiphysis 6

Treatment Duration and Outcomes

• Continue until epiphyseal closure documented or height velocity <2 cm/year 5, 6
• Expected gain: approximately 7 cm increase in final adult height after 2-5 years of treatment 5

Chronic Kidney Disease-Associated Growth Failure

GH therapy at 0.35 mg/kg/week divided into daily injections is indicated for CKD patients with persistent growth failure (height <3rd percentile and velocity <25th percentile for >6 months) after optimizing modifiable factors. 3, 7

Optimize Before Starting GH

• Nutritional support: ensure adequate caloric intake via gastrostomy/nasogastric tube if needed 3
• Correct metabolic acidosis: target serum bicarbonate ≥22 mEq/L with sodium bicarbonate supplementation 3
• Manage CKD-mineral bone disease: control secondary hyperparathyroidism to PTH within CKD-stage-appropriate range; maintain 25-hydroxyvitamin D >30 ng/mL 3
• Optimize dialysis adequacy: use biocompatible solutions and ensure adequate urea clearance 3
• Electrolyte repletion: provide sodium and free water supplementation in salt-wasting conditions 3

Constitutional Delay of Growth and Puberty

• Reassurance and observation for adolescents with delayed bone age matching height age, family history of late puberty, and predicted adult height within normal range 1
• Endocrinology referral if no pubertal signs by age 14 in boys or 13.5 in girls for consideration of pubertal induction 3, 4

Idiopathic Short Stature

GH therapy at 0.3 mg/kg/week divided daily is FDA-approved for ISS defined as height SDS ≤-2.25 with growth rates unlikely to permit normal adult height, after excluding other treatable causes. 7

Turner Syndrome

GH therapy at 0.375 mg/kg/week divided into 3-7 injections weekly is indicated for short stature associated with Turner syndrome. 7

Critical Pitfalls to Avoid

• Do not use testosterone in prepubertal children to stimulate growth, as it causes premature epiphyseal closure and permanently limits final height 5
• Do not start GH without first correcting hypothyroidism, as thyroid hormone is required for GH efficacy 3, 5
• Do not initiate GH in patients with active malignancy, uncontrolled diabetes, closed epiphyses, or papilledema 3, 6, 7
• Do not rely on single height measurement; growth velocity over ≥6 months is essential to identify true growth failure 3, 4
• Do not overlook nutritional deficiency, the most common cause of growth failure, which may resolve with feeding optimization alone 3, 2

When to Refer to Pediatric Endocrinology

• Height >2 SD below mean with decreased height velocity despite addressing modifiable factors 1
• Suspected GH deficiency based on low IGF-1 and delayed bone age 3, 1
• Pubertal delay: boys with testicular volume <4 mL at age 14; girls with breast stage <B2 at age 13.5 3, 4
• Disproportionate short stature or dysmorphic features suggesting genetic syndrome 1
• Growth failure with systemic symptoms requiring subspecialty coordination 2