ABP Pediatric Endocrinology common mistakes
ABP Pediatric Endocrinology · Understand the traps and how to avoid them.
Judging a child's growth from a single height percentile or a height velocity calculated over less than six months, without plotting serial measurements on the correct chart.
Cross-sectional percentiles hide growth failure, and short intervals amplify measurement error and seasonal variation; candidates often treat one low point as diagnostic.
What to do instead
Use at least two measurements six or more months apart, calculate cm/year, plot on the age- and sex-appropriate chart, adjust for prematurity, and compare with mid-parental height and bone age before labeling short stature.
Diagnosing growth hormone deficiency after a single low random GH level or a low IGF-1, without provocative testing or excluding nutrition, thyroid, celiac, and chronic disease.
GH is pulsatile, so random levels are uninterpretable; IGF-1 falls with undernutrition and hypothyroidism, and candidates anchor on the low number instead of the clinical trajectory.
What to do instead
Screen with IGF-1 and IGFBP-3, bone age, thyroid function, celiac serology, and a growth history; confirm with two provocative GH stimulation tests and obtain brain MRI when deficiency is biochemically confirmed.
Dismissing congenital hypothyroidism because the newborn screen was normal, or treating a mildly elevated TSH in an acutely ill infant as permanent hypothyroidism without repeat testing.
Screening can miss cases, especially in preterm or sick newborns, while illness and recovery transiently alter TSH and free T4; candidates overtrust one result in either direction.
What to do instead
Repeat TSH and free T4 after recovery using age-specific ranges; treat promptly if TSH is markedly elevated or free T4 is low with clinical features, and recheck before committing to lifelong therapy.
Delaying hydrocortisone in suspected adrenal crisis until laboratory results return, or giving a low replacement dose instead of stress-dose therapy.
Adrenal crisis is rapidly fatal and candidates wait for confirmatory cortisol or electrolytes; replacement dosing is inadequate under acute stress.
What to do instead
Draw a critical sample if it will not delay treatment, then immediately give stress-dose hydrocortisone (about 50 to 100 mg/m2 IV) with isotonic fluid resuscitation and glucose monitoring; do not wait for labs.
Applying adult DKA fluid protocols to children, using rapid large isotonic boluses beyond shock resuscitation, and failing to perform hourly neurologic checks for cerebral edema.
Pediatric DKA carries a higher risk of cerebral edema with rapid osmotic shifts, and candidates copy adult algorithms or focus only on glucose correction.
What to do instead
Follow pediatric DKA guidance: give 10 mL/kg isotonic bolus only for shock, then replace deficit plus maintenance slowly over 24 to 48 hours; monitor mental status hourly and treat suspected cerebral edema immediately with mannitol or hypertonic saline.
Diagnosing central precocious puberty in a girl with breast budding alone, without documenting growth acceleration, bone age advancement, or pubertal progression.
Premature thelarche is common and isolated, while candidates overinterpret a single physical finding and order puberty-blocking therapy prematurely.
What to do instead
Track growth velocity and Tanner staging over three to six months, obtain bone age and pelvic ultrasound, and use basal or GnRH-stimulated LH; observe isolated premature thelarche without treatment.
Assigning a sex or ordering only a karyotype in a newborn with ambiguous genitalia, while omitting urgent 17-hydroxyprogesterone, electrolytes, and glucose.
Congenital adrenal hyperplasia can present with salt-wasting crisis in the first weeks, and candidates focus on diagnosis labeling before stabilizing the infant.
What to do instead
Treat as an emergency: check 17-OHP, electrolytes, glucose, karyotype, and pelvic ultrasound, involve a multidisciplinary DSD team, avoid immediate sex assignment, and start hydrocortisone and fludrocortisone if CAH is suspected.
Interpreting low total calcium or low phosphate without correcting calcium for albumin or checking PTH, 25-hydroxyvitamin D, alkaline phosphatase, and urine calcium-to-creatinine ratio.
Total calcium falls with hypoalbuminemia, and rickets or hypoparathyroidism cannot be classified from a single chemistry; candidates stop at the low number.
What to do instead
Obtain ionized calcium or correct total calcium for albumin, then check PTH, 25-OH vitamin D, magnesium, phosphate, alkaline phosphatase, and a spot urine calcium-to-creatinine ratio; obtain wrist or knee radiographs when rickets is suspected.
Ordering cortisol, thyroid, and growth hormone testing in every child with obesity before assessing lifestyle, blood pressure, lipids, liver enzymes, and glycemic status.
Most pediatric obesity is exogenous, and endocrine testing has high false-positive rates; candidates look for a hormonal cause instead of screening for comorbidities.
What to do instead
Screen blood pressure, fasting lipids, hemoglobin A1c, and ALT; reserve endocrine testing for red flags such as poor linear growth, dysmorphic features, or signs of Cushing syndrome or hypothyroidism.
Classifying hyponatremia or hypernatremia without assessing volume status, urine osmolality, and urine sodium, or correcting sodium faster than recommended.
SIADH, salt wasting, dehydration, and water intoxication require different treatments, and candidates treat the sodium number rather than the physiology; rapid correction risks osmotic demyelination.
What to do instead
Check serum and urine osmolality, urine sodium, and volume status; treat the underlying cause, restrict free water in SIADH, replace deficits in dehydration, and correct sodium slowly with frequent monitoring.