Endocrinology

Question 1

Hi there 🫵🏼 سمِّي الله

Answer 1

بسم الله الرّحمن الرّحيم 💡

Question 2

Why is a stress-dose of hydrocortisone necessary in children with chronic adrenal insufficiency during infections?

Answer 2

✅ HPA axis suppression from chronic glucocorticoids leads to low endogenous cortisol, which can’t rise in response to stress ➡️ risk of adrenal crisis (hypotension, shock)

Question 3

Why is continuing the usual daily glucocorticoid dose during stress insufficient in adrenal insufficiency?

Answer 3

⛔ Normal doses don’t meet the body’s increased demand during stress
✅ Stress increases cortisol needs ➡️ require higher doses temporarily

Question 4

Why should glucocorticoid therapy never be stopped abruptly in patients with adrenal insufficiency?

Answer 4

⛔ Abrupt cessation can trigger adrenal crisis

Question 5

Why is cortisol testing not appropriate as a first step in suspected adrenal crisis during infection?

Answer 5

⛔ Cortisol levels take time and don’t help in acute decision-making
✅ Treat empirically with stress-dose hydrocortisone → delay in treatment risks shock

Question 6

What is the main cause of hypokalemia during diabetic ketoacidosis (DKA) treatment?

Answer 6

✅ Insulin therapy shifts potassium back into cells, unmasking total body potassium depletion and leading to hypokalemia

Question 7

What is the earliest ECG sign of hypokalemia in a child treated for DKA?

Answer 7

✅ Flattened T waves
## footnote

➡️ More severe: ST depression, U waves, prolonged QT, and QRS widening

Question 8

When should potassium be added to IV fluids during DKA treatment?

Answer 8

✅ If serum potassium is < 5.5 mEq/L and the child is producing urine ➕

Question 9

Why is hypernatremia not expected during DKA treatment?

Answer 9

⛔ DKA usually causes pseudohyponatremia due to osmotic effect of glucose
##footnote

Sodium may correct upward with fluid resuscitation, but true hypernatremia is rare

Question 10

What are the key clinical features of constitutional delay of growth and puberty (CDGP)?

Answer 10

✅ Short stature
✅ Normal birth weight and height
✅ Delayed bone age
✅ Slowed but normal variant growth velocity
✅ Delayed puberty with normal labs
✅ Often positive family history of late bloomers

Question 11

What distinguishes constitutional delay of growth and puberty (CDGP) from pathologic short stature?

Answer 11

✅ CDGP shows normal labs (GH, IGF-1, TSH)
✅ Delayed bone age but normal final adult height
⛔ No systemic disease or endocrine disorder
✅ Family history of similar growth pattern supports diagnosis

Question 12

How is constitutional delay of growth and puberty (CDGP) managed?

Answer 12

✅ Reassurance and follow-up
✅ If >2 years delay in puberty → consider short-term low-dose testosterone to initiate puberty

Question 13

What are the hallmark clinical features of primary adrenal insufficiency in children?

Answer 13

✅ Hypoglycemia
✅ Nausea, vomiting, abdominal pain
✅ Hypotension (especially orthostatic)
✅ Hyperpigmentation (due to ↑ACTH → ↑MSH)
✅ Hyponatremia (due to cortisol + aldosterone deficiency)
✅ Hyperkalemia (due to aldosterone deficiency)

Question 14

Why does hyperpigmentation occur in Addison’s disease but not in secondary adrenal insufficiency?

Answer 14

✅ In Addison’s: ↓Cortisol → ↑ACTH → derived from POMC, which also produces MSH → melanocyte stimulation
⛔ In secondary AI (hypopituitarism): ACTH is low → no MSH → no hyperpigmentation

Question 15

What distinguishes primary adrenal insufficiency from other causes of hypoglycemia in children?

Answer 15

✅ Only Addison’s presents with:
• Hyperpigmentation
• Hyponatremia + hyperkalemia
• Low cortisol despite stress
• ↑ACTH
⛔ Other causes (e.g. sulfonylurea, glycogen storage disease, FA oxidation defects) don’t cause pigmentation or electrolyte changes like Addison’s.

Question 16

What is the classic presentation of Erb’s palsy (C5-C6 injury) in newborns?

Answer 16

🚩 “Waiter’s tip” position:
• Arm hangs at side (adducted)
• Medially rotated shoulder
• Extended & pronated forearm
• Absent biceps reflex
👉🏼 Due to paralysis of deltoid, biceps, brachialis (C5-C6)

Question 17

What are the most common risk factors for Erb’s palsy in neonates?

Answer 17

✅ Birth weight > 4 kg (macrosomia)
✅ Shoulder dystocia
✅ Multiparity
✅ Maternal diabetes
✅ Excessive maternal weight gain

Question 17

What are the prognosis and treatment options for Erb’s palsy in neonates?

Answer 17

✅ Most cases improve spontaneously in 3–6 months
✅ Physical therapy to prevent contractures and improve function
✅ Surgery if no improvement by 3–6 months (nerve grafts or transfers)

Question 18

What are the classic triad symptoms of Type 1 Diabetes Mellitus (T1DM) in children, and what is the most common initial presentation of it in children?

Answer 18

✅ Polyuria
✅ Polydipsia
✅ Weight loss

✅ Diabetic ketoacidosis (DKA) – seen in about 1/3 of newly diagnosed pediatric T1DM cases.

Question 19

What causes polyuria in uncontrolled T1DM?

Answer 19

📈 Severe hyperglycemia leads to glycosuria
➡️ Osmotic diuresis
➡️ Polyuria + electrolyte loss + dehydration

Question 20

Why is hyponatremia commonly seen in DKA?

Answer 20

✅ Due to osmotic water shift from intracellular to extracellular space from high glucose
📉 Serum sodium is diluted (pseudohyponatremia)
🧠 Corrected Na⁺ = Measured Na⁺ + 1.6 for every 10

Question 21

How can we differentiate between true polyuria (diabetes) and psychogenic polydipsia?

Answer 21

🚩 Perform fluid deprivation test:
• 👉🏼 In psychogenic polydipsia → urine output decreases, osmolality increases
• 👉🏼 In osmotic diuresis (T1DM) → polyuria continues due to glycosuria
✅ Confirms “true” polyuria vs. excessive water intake

Question 22

What is the recommended amount and type of physical activity for children with type 1 diabetes (T1DM)?

Answer 22

✅ 60 min/day of moderate to vigorous aerobic activity
➕ 3 days/week of vigorous bone- and muscle-strengthening exercises

Question 23

What is the main acute complication of exercise in children with T1DM?

Answer 23

🚨 Hypoglycemia — can occur during or after exercise due to increased glucose uptake by muscles.

Question 24

What are key strategies to prevent hypoglycemia in children with T1DM during exercise?

Answer 24

✅ Frequent glucose monitoring (before, during, after) ✅ Adjusting insulin dose around exercise ✅ Keep fast-acting carbs (e.g. glucose tablets, juice) readily available

Question 25

Why is exercise beneficial for children with T1DM?

Answer 25

🧠 Enhances insulin sensitivity 📉 Improves blood glucose regulation ✅ Increases muscle glucose uptake and insulin receptors

Question 26

Why must vigorous exercise be avoided in poorly controlled T1DM?

Answer 26

🚨 It can increase counter-regulatory hormones (epinephrine, cortisol) ➡️ 📈 leading to ketoacidosis

Question 27

What is the difference between hyperthyroidism and thyrotoxicosis?

Answer 27

📌 Hyperthyroidism = Increased production of thyroid hormone by the thyroid gland. 📌 Thyrotoxicosis = Clinical syndrome of excess circulating thyroid hormone from any source (e.g., Graves, thyroiditis, exogenous intake).

Question 28

What is the most common cause of hyperthyroidism in children?

Answer 28

✅ Graves disease — an autoimmune condition causing excess thyroid hormone production.

Question 29

What distinguishes Graves disease from other causes of thyrotoxicosis when labs are inconclusive?

Answer 29

Radioactive iodine uptake (RAIU)

Question 30

What causes lid lag and stare (Dalrymple sign) in thyrotoxicosis?

Answer 30

🚨 Increased sympathetic activity — stimulates the levator palpebrae muscle, causing retraction of the upper eyelid.

Question 31

Which thyroid antibodies are elevated in Hashimoto thyroiditis, not Graves disease?

Answer 31

🔷 Anti-thyroid peroxidase (anti-TPO) 🔷 Anti-thyroglobulin antibodies ⛔ They are not the cause of lid lag in thyrotoxicosis.

Question 32

What iatrogenic cause can lead to thyrotoxicosis, even in the absence of hyperthyroidism?

Answer 32

💊 Excess levothyroxine therapy ➡️ raises circulating thyroid hormones 📌 This is a form of thyrotoxicosis without hyperthyroidism.

Question 33

What is the most common cause of congenital adrenal hyperplasia (CAH) and what are the typical hormonal changes in its deficiency?

Answer 33

✅ 21-hydroxylase deficiency ⬇️ Cortisol ⬇️ Aldosterone ⬆️ ACTH (due to loss of negative feedback) ⬆️ 17-hydroxyprogesterone ⬆️ Androgens (e.g., testosterone)

Question 34

What is the hallmark lab finding in both classic and nonclassic 21-hydroxylase deficiency?

Answer 34

✅ Elevated 17-hydroxyprogesterone levels

Question 35

What are the typical clinical signs of nonclassic 21-hydroxylase deficiency in females?

Answer 35

✅ Precocious pubarche, hirsutism, acne, irregular menses

Question 36

What is the first-line treatment for symptomatic nonclassic 21-hydroxylase deficiency, and what its purpose?

Answer 36

✅ Suppress ACTH ➡️ Decrease adrenal androgens ➡️ Normalize growth & puberty timing

Question 37

Why are GnRH agonists not used in nonclassic CAH?

Answer 37

❌ GnRH agonists treat central precocious puberty, not peripheral androgen excess

Question 38

What electrolyte and metabolic abnormalities are commonly seen in classic CAH with salt-wasting?

Answer 38

🚨 Hyponatremia, hyperkalemia, hypoglycemia, and metabolic acidosis

Question 39

What is the hallmark lab marker used for diagnosing classic CAH (21-hydroxylase deficiency)?

Answer 39

⬆️ ACTH is produced from POMC ➡️ POMC also produces alpha-MSH ➡️ MSH stimulates melanocytes ➡️ hyperpigmentation (e.g., scrotum)

Question 40

What are the clinical features of classic CAH in females and males?

Answer 40

👧 Females: Ambiguous genitalia (virilization) 👦 Males: Normal genitalia but may present later with salt-wasting crisis Both: Dehydration, vomiting, failure to thrive, hyperpigmentation

Question 41

What is the most common cause of congenital hypothyroidism?

Answer 41

✅ Thyroid dysgenesis

Question 42

Why are most newborns with congenital hypothyroidism asymptomatic at birth?

Answer 42

Because of transplacental passage of maternal T4, which supplies ~33% of normal fetal thyroid hormone levels at birth.

Question 43

What are clinical signs of congenital hypothyroidism that may appear after birth?

Answer 43

📍 Widely open fontanelles 📍 Prolonged jaundice 📍 Lethargy (somnolence) 📍 Macroglossia 📍 Umbilical hernia 📍 Constipation 📍 Hypotonia ##footnote 🧠💡Mnemonic: “LARGE Tongue & SLOW Baby”

Question 44

Why is pseudohypothyroidism not classified as congenital hypothyroidism?

Answer 44

Because it results from peripheral resistance to thyroid hormone ➡️ TSH and T4 levels are high, but tissues are unresponsive

Question 45

What are the causes of congenital hypothyroidism other than thyroid dysgenesis?

Answer 45

Dyshormonogenesis (15%), maternal antithyroid drugs, TSH receptor mutations, iodine deficiency, and central hypothyroidism.

Question 46

What is the classic clinical triad of polycystic ovary syndrome (PCOS)?

Answer 46

🟰 Oligo- or anovulation ➕ clinical/biochemical hyperandrogenism ➕ polycystic ovarian morphology on ultrasound.

Question 47

What two skin signs in an overweight adolescent female strongly suggest insulin resistance and hyperandrogenism in PCOS?

Answer 47

➕ Acanthosis nigricans (insulin resistance) ➕ Hirsutism (androgen excess)

Question 48

What metabolic abnormalities are commonly associated with PCOS?

Answer 48

Obesity, insulin resistance, and metabolic syndrome

Question 49

What is the first-line therapy for adolescents and adults with PCOS who do not desire fertility?

Answer 49

✅ Combined estrogen-progestin oral contraceptives ➕ Antiandrogens ➡️ fot hirsutism

Question 50

What lifestyle recommendation is central to all PCOS management plans?

Answer 50

✅ Weight loss via diet and physical activity ➕use metformin ➡️ Improves insulin sensitivity, regulates cycles

Question 51

What clinical triad is characteristic of childhood cerebral adrenoleukodystrophy (ALD)?

Answer 51

➕ Adrenal insufficiency ➕ Progressive cognitive/behavioral decline ➕ White matter demyelination on MRI

Question 52

What diagnostic test confirms the diagnosis of adrenoleukodystrophy?

Answer 52

1. 📈 Elevated VLCFA in serum 2. ⬆️ ACTH, ⬇️ cortisol → adrenal insufficiency 3. 🧠 Brain MRI showing occipitoparietal white matter demyelination

Question 53

What is adrenomyeloneuropathy (AMN) and how does it differ from childhood cerebral ALD?

Answer 53

Adult-onset ALD variant ➡️ Slowly progressive spastic paraparesis ➡️ May involve adrenal dysfunction but with milder CNS effects

Question 54

What is the most common form of ALD and its typical presentation?

Answer 54

👦🏼 Childhood cerebral ALD ➡️ Starts with behavioral/academic decline ➡️ Progresses to neurologic deficits and adrenal insufficiency

Question 55

Peroxisomal disorders result in the accumulation of __________ due to defective oxidation pathways.

Answer 55

✅ Very Long Chain Fatty Acids (VLCFAs)

Question 56

What is the most appropriate management plan for adrenoleukodystrophy in a child with adrenal insufficiency and neurological decline?

Answer 56

1. 💉 Hormone replacement for adrenal insufficiency 2. 🥦 Dietary restriction of VLCFAs 3. 🧬 Consider hematopoietic stem cell transplant in early cerebral disease

Question 57

What are the 4 diagnostic criteria for diabetic ketoacidosis (DKA) in children?

Answer 57

✅ pH < 7.3 ✅ HCO₃⁻ < 15 mEq/L ✅ Blood or urine ketones ↑ ✅ Glucose > 200 mg/dL 🧪📉 DKA = Metabolic acidosis + ketonemia + hyperglycemia

Question 58

What does a corrected sodium >150 mmol/L suggest in DKA?

Answer 58

🚨 Severe hypernatremic dehydration ➡️ requires slower fluid replacement to avoid cerebral edema.

Question 59

How do you correct serum sodium in a hyperglycemic patient to assess for true hyponatremia?

Answer 59

✅ Corrected Na⁺ = Measured Na⁺ + 1.6 mEq/L for every 100 mg/dL of glucose over 100 👉🏼 Used to distinguish true vs. pseudohyponatremia in hyperglycemia 📌 Example: Na⁺ = 124, Glucose = 900 → Correction = 124 + (1.6 × 8) = 136.8 mEq/L

Question 60

In T1DM with hyperglycemia, apparent hyponatremia is often due to __________, and does not require treatment if corrected sodium is normal.

Answer 60

✅ Pseudohyponatremia

Question 61

Which of the following corrected sodium values indicates true hypernatremic dehydration requiring treatment? A) 138 mmol/L B) 132 mmol/L C) 148 mmol/L D) 156 mmol/L E) 140 mmol/L

Answer 61

✅ D) 156 mmol/L 🚨 Corrected Na⁺ >150 mmol/L ➡️ indicates hypernatremic dehydration → needs slow IV fluid replacement

Question 62

What are the goals of DKA management in children?

Answer 62

1️⃣ Restore perfusion with careful fluid resuscitation 2️⃣ Correct acidosis and hyperglycemia with IV insulin 3️⃣ Replace electrolytes (especially potassium) 4️⃣ Monitor for cerebral edema and other complications

Question 63

What is the expected urine osmolarity in DKA?

Answer 63

⬆️ Increased due to osmotic diuresis from glucosuria and ketonuria. ⛔ Low urine osmolarity suggests diabetes insipidus, not DKA.

Question 64

What causes the metabolic acidosis in diabetic ketoacidosis (DKA)?

Answer 64

⛔ Insulin deficiency ➡️ ↑ lipolysis ➡️ ↑ free fatty acids ➡️ hepatic ketogenesis ➡️ ↑ ketone bodies (β-hydroxybutyrate, acetoacetate, acetone) ➡️ metabolic acidosis

Question 65

What is the most serious complication of DKA treatment in children, and what are its signs?

Answer 65

Cerebral edema ➡️ symptoms: headache, bradycardia, hypertension, vomiting, altered consciousness, seizures

Question 66

What is the best immediate treatment for suspected cerebral edema in a child with DKA?

Answer 66

🚩Elevate head of bed 🚩Restrict fluids 🚩Administer IV mannitol immediately (or hypertonic saline if mannitol unavailable)

Question 67

Why are excessive fluids and insulin dangerous during DKA treatment?

Answer 67

They may contribute to rapid osmotic shifts and cerebral edema formation. ⚠️ Must monitor closely and rehydrate slowly.

Question 68

Why is bicarbonate not routinely recommended in DKA treatment?

Answer 68

Bicarbonate may worsen intracellular acidosis and is not shown to improve outcomes in mild/moderate DKA. Used only in refractory acidosis or life-threatening hyperkalemia.

Question 69

Which ketone body predominates in DKA and may not be detected on standard urine tests?

Answer 69

Beta-hydroxybutyrate

Question 70

impaired glucose tolerance (IGT) defined as ______, while impaired fasting glucose (IFG) means fasting glucose ________.

Answer 70

✅ oral glucose tolerance test (OGTT)= 140–199 mg/dL ✅ 100–125 mg/dL

Question 71

What are the diagnostic criteria for diabetes mellitus in children?

Answer 71

❗ Any one of the following: • Fasting glucose ≥ 126 mg/dL • OGTT glucose ≥ 200 mg/dL • HbA1c ≥ 6.5% • Random glucose ≥ 200 mg/dL with classic symptoms (e.g., polyuria, polydipsia, weight loss)

Question 72

What are the diagnostic criteria for Maturity-Onset Diabetes of the Young (MODY)?

Answer 72

✅ Diabetes in ≥3 generations (autosomal dominant) ✅ Onset before age 25 in at least 1 individual ✅ Low C-peptide indicating impaired insulin secretion ✅ Negative diabetes autoantibodies

Question 73

MODY is a form of monogenic diabetes due to a primary defect in insulin secretion. It is inherited in a __________ manner and often shows __________ C-peptide.

Answer 73

✅ Autosomal dominant; low

Question 74

What distinguishes MODY from type 1 diabetes mellitus?

Answer 74

✅ MODY is non-autoimmune, has preserved beta-cell function, and often requires oral agents (e.g., sulfonylureas). ⛔ Type 1 DM is autoimmune, with positive antibodies, C-peptide low or absent, and requires lifelong insulin.

Question 75

What distinguishes MODY from type 2 diabetes mellitus?

Answer 75

✅ MODY is monogenic with autosomal dominant inheritance, usually in lean patients, with onset <25 years. ⛔ Type 2 DM is polygenic, linked to obesity, insulin resistance, and usually appears in adolescence or adulthood.

Question 76

What clinical findings are most suggestive of Cushing syndrome in a child?

Answer 76

✅ Arrested growth + central obesity + purple striae + fatigue + hirsutism , Moon face ➕ Hypertension and hyperglycemia support diagnosis

Question 77

What are the three initial tests used to establish the diagnosis of Cushing syndrome?

Answer 77

1. Midnight salivary cortisol 2. 24-hour urinary free cortisol 3. Low-dose dexamethasone suppression test (1 mg overnight)

Question 78

What is the most common cause of Cushing’s syndrome in general (all ages)?

Answer 78

✅ Iatrogenic from prolonged high-dose glucocorticoid therapy

Question 79

Why is an oral glucose tolerance test (OGTT) not helpful for diagnosing Cushing syndrome?

Answer 79

❌ OGTT is often abnormal due to insulin resistance but has no diagnostic utility for Cushing syndrome

Question 80

What lab test is used to evaluate for pheochromocytoma or adrenocortical carcinoma, not Cushing syndrome?

Answer 80

✅ Urinary catecholamines

Question 81

What are the 8 FDA-approved pediatric indications for growth hormone therapy?

Answer 81

1. Growth hormone (GH) deficiency 2. Turner syndrome 3. Chronic renal failure before transplantation 4. Idiopathic short stature 5. Small-for-gestational-age (SGA) short stature 6. Prader-Willi syndrome 7. SHOX gene abnormality 8. Noonan syndrome

Question 82

What is the GH therapy indication for a child born small for gestational age (SGA)?

Answer 82

✅ GH is approved if SGA short stature persists beyond early childhood.

Question 83

What hormonal profile suggests peripheral (gonadotropin-independent) precocious puberty?

Answer 83

✅ Low gonadotropins (LH/FSH) with high sex steroids

Question 84

What is the most likely cause of peripheral precocious puberty in a child with low LH/FSH and high DHEA/testosterone?

Answer 84

✅ Adrenocortical carcinoma

Question 85

Why is congenital adrenal hyperplasia (CAH) unlikely to cause precocious puberty at age 6 if it was not diagnosed earlier?

Answer 85

⛔ Classic CAH typically presents neonatally or in early infancy, often detected by newborn screening. Late onset at 6 years makes it less likely.

Question 86

Why is hypothalamic hamartoma not the likely cause of precocious puberty in a child with low LH/FSH?

Answer 86

⛔ Hypothalamic hamartomas cause central precocious puberty (gonadotropin-dependent), not peripheral.

Question 87

What tumors should be considered in peripheral precocious puberty with elevated sex hormones and low LH/FSH?

Answer 87

✅ Adrenal tumors, gonadal tumors, and HCG-secreting tumors (e.g., germinomas).

Question 88

What distinguishes primary from secondary adrenal insufficiency?

Answer 88

✅ Primary has ⬆️ ACTH and hyperpigmentation; secondary has ⬇️ ACTH and no pigmentation

Question 89

What are the cardinal symptoms of acute adrenal crisis in children?

Answer 89

✅ Hypoglycemia, hypotension/shock, vomiting, lethargy, abdominal pain, and electrolyte abnormalities (low Na⁺, high K⁺)

Question 90

What is the immediate treatment for adrenal crisis (acute primary adrenal insufficiency)?

Answer 90

✅ IV 0.9% saline + 5% dextrose to correct hypovolemia, hyponatremia, and hypoglycemia ➕ IV hydrocortisone bolus ➡️ followed by maintenance steroids

Question 91

What are the key clinical and lab findings that suggest primary adrenal insufficiency in a child?

Answer 91

✅ Fatigue, hypotension, tachycardia, nausea/vomiting, tongue hyperpigmentation ✅ Labs: Hyponatremia, hyperkalemia, hypoglycemia, low cortisol, metabolic acidosis

Question 92

Why does cortisol deficiency cause hypotension and shock?

Answer 92

✅ Cortisol is needed for vascular tone and inotropy ⬇️ Cortisol ➡️ ⬇️ responsiveness to epinephrine and angiotensin II

Question 93

What lab findings confirm adrenal insufficiency with mineralocorticoid loss?

Answer 93

✅ Hyponatremia, hyperkalemia, hypoglycemia, and metabolic acidosis

Question 94

How does AVP (ADH) contribute to hyponatremia in adrenal insufficiency?

Answer 94

✅ Low BP + cortisol deficiency → ⬆️ AVP secretion → ⬇️ free water excretion → dilutional hyponatremia

Question 95

What ocular finding is strongly suggestive of Graves’ disease in a child?

Answer 95

✅ Proptosis (exophthalmos) with a staring look

Question 96

In a child with nervousness, sleep disturbances, mood swings, and diffuse goiter, Graves disease is suspected. The most specific test to confirm the diagnosis is measurement of ________, while ________ uptake is increased on scintigraphy if antibody testing is inconclusive.

Answer 96

✅ Thyrotropin receptor antibodies (TSI or TBII), radioactive iodine (RAI)

Question 97

Why is methimazole preferred over PTU in pediatric Graves’ disease treatment?

Answer 97

✅ PTU has been linked to severe hepatotoxicity and is avoided in children methimazole is the first-line treatment

Question 98

When is radioactive iodine or surgery considered in pediatric Graves’ disease?

Answer 98

✅ When there is poor medication compliance, severe side effects, or treatment failure

Question 99

What distinguishes Kallmann syndrome from Klinefelter syndrome in labs?

Answer 99

✅ Kallmann = low LH/FSH/testosterone (central cause) Klinefelter = high LH/FSH, low testosterone (primary gonadal failure) 📌 Klinefelter has 47,XXY karyotype

Question 100

What is the treatment for Kallmann syndrome in males?

Answer 100

✅ Testosterone replacement

Question 101

How is Kallmann syndrome different from Prader-Willi syndrome?

Answer 101

✅ Kallmann has anosmia; Prader-Willi has hyperphagia & obesity

Question 102

Why is Turner syndrome ruled out in a patient with hypogonadism and anosmia?

Answer 102

✅ Turner syndrome occurs in females (45,X) and presents with hypergonadotropic hypogonadism

Question 103

What is the most common cause of acquired hypothyroidism in children?

Answer 103

✅ Hashimoto’s thyroiditis (autoimmune thyroiditis)

Question 104

What is a common early clinical sign of acquired hypothyroidism in children?

Answer 104

✅ Growth delay with weight gain

Question 105

Which medication types can cause acquired hypothyroidism?

Answer 105

✅ Amiodarone, anticonvulsants (e.g. phenytoin), methimazole, lithium

Question 106

What are typical physical exam findings in acquired hypothyroidism?

Answer 106

✅ Bradycardia, myxedema, constipation, goiter, delayed bone age

Question 107

Craniopharyngioma is a common childhood tumor typically located in the ______ region, and presents with symptoms such as ______ and ______ due to pituitary hormone deficiencies.

Answer 107

✅ suprasellar region; short stature and delayed puberty

Question 108

On brain imaging, craniopharyngioma appears as a ______ mass with ______ components, and may cause visual symptoms like ______ due to compression of the optic chiasm.

Answer 108

✅ heterogeneous mass; solid and cystic components; bitemporal hemianopsia

Question 109

The treatment of choice for craniopharyngioma is ______. Chemotherapy is ______ indicated, and radiation may be considered if complete resection is not possible.

Answer 109

✅ surgical resection; not

Question 110

In a girl <8 years with early secondary sexual characteristics and LH that increases after LHRH stimulation, the diagnosis is ______ precocious puberty, which is treated by continuous administration of ______ to suppress pituitary gonadotropin release.

Answer 110

✅ central (gonadotropin-dependent) precocious puberty; GnRH agonists (e.g., LHRH)

Question 111

Why are estrogen or progesterone treatments inappropriate for managing central precocious puberty, and what are the risks of observation alone?

Answer 111

➡️ Estrogen or progesterone treatments are inappropriate because they can worsen the signs of precocious puberty by further promoting secondary sexual characteristics. ➡️ Observation alone is not recommended in rapidly progressing cases, as it denies the patient timely intervention and may lead to reduced adult height and psychosocial issues.

Question 112

What is hemihypertrophy, and with which syndrome and complications is it associated?

Answer 112

➡️ Hemihypertrophy is asymmetric overgrowth of one side of the body. ➡️ It is a hallmark of Beckwith-Wiedemann syndrome ➡️ And is associated with a higher risk of abdominal tumors such as Wilms tumor, hepatoblastoma, and adrenal carcinoma.

Question 113

_________ syndrome presents with macroglossia, abdominal wall defects, hemihypertrophy, ear creases/pits, and neonatal hypoglycemia due to hyperinsulinism.

Answer 113

Beckwith-Wiedemann

Question 114

A neonate with low calcium, high phosphate, and low PTH likely has which condition, and how does it present?

Answer 114

Transient neonatal hypoparathyroidism — presents with tremor, jitteriness, or seizures due to symptomatic hypocalcemia. ##footnote ✅ Clue 🕵️‍♂️: Hyperphosphatemia + low PTH rules out vitamin D deficiency and points to PTH deficiency.

Question 115

Why is congenital hypothyroidism unlikely to cause hypocalcemia with hyperphosphatemia in a neonate?

Answer 115

⛔ Congenital hypothyroidism is usually asymptomatic at birth due to maternal T4, and does not cause electrolyte disturbances like hypocalcemia or hyperphosphatemia.

Question 116

Why is Turner syndrome an unlikely cause of hypocalcemia with hyperphosphatemia in neonates?

Answer 116

⛔ Turner syndrome causes gonadal dysgenesis, short stature, and cardiac/renal anomalies, but does not cause hypocalcemia or phosphate imbalance in the neonatal period.

Question 117

Why is congenital vitamin D deficiency an unlikely cause of hypocalcemia with hyperphosphatemia?

Answer 117

⛔ Congenital vitamin D deficiency typically causes hypocalcemia with hypophosphatemia, not hyperphosphatemia.

Question 118

A newborn with low calcium and high phosphate levels, born to a diabetic mother and showing signs of jitteriness or seizures, most likely has ________, whereas similar lab findings in a dysmorphic infant with cardiac defects may suggest ________ syndrome.

Answer 118

✅ Transient hypoparathyroidism, DiGeorge syndrome (CATCH22) ##Footnote 🔷 Clues: • Transient hypoparathyroidism ⟶ common in infants of diabetic mothers • CATCH22 (DiGeorge) ⟶ hypocalcemia + cardiac anomalies + facial dysmorphism

Question 119

What lab findings distinguish central from primary congenital hypothyroidism in neonates?

Answer 119

✅ Central: Low free T4 with normal or low TSH ✅ Primary: Low free T4 with high TSH (often >100 mU/L) 💡 Central = pituitary origin; Primary = thyroid gland defect (e.g., dysgenesis)

Question 120

What clinical features strongly suggest Cushing’s syndrome in a child?

Answer 120

✅ Moon face, central obesity, growth arrest, purple striae, hypertension, hyperglycemia, emotional lability, and delayed puberty

Question 121

What clinical findings in a newborn suggest congenital GH deficiency due to pituitary/hypothalamic defect?

Answer 121

✅ Severe hypoglycemia, micropenis, apnea, high-pitched cry, midline facial defects (e.g., cleft palate, flat nasal bridge, solitary central incisor), ± cholestatic jaundice

Question 122

What is the definitive treatment for confirmed GH deficiency in a neonate with hypoglycemia and midline defects?

Answer 122

✅ Recombinant human GH (subcutaneous injection daily) ➡️ Begin as early as possible to improve outcomes

Question 123

What initial lab findings support the suspicion of GH deficiency in neonates with hypoglycemia?

Answer 123

✅ Low IGF-1 levels suggest GH deficiency ➕ Confirm with provocative GH testing ➕ Evaluate other pituitary hormones: TSH, ACTH, cortisol, LH/FSH

Question 124

In a hypoglycemic infant, what two findings point toward hyperinsulinemic hypoglycemia?

Answer 124

✅ Low blood glucose ➕ Absent ketones in blood and urine ➕ Inappropriately elevated insulin (>5 µU/mL) during hypoglycemia

Question 125

What physical findings and labs suggest a non-insulin cause of hypoglycemia such as hormone deficiency or metabolic disease?

Answer 125

✅ Ketones present → suggests ketotic hypoglycemia, hormone deficiency, or glycogen storage disorders ✅ Hepatomegaly → glycogen storage disease ✅ Hyperpigmentation → adrenal insufficiency ✅ Growth delay/neuro signs → pituitary deficiency

Question 126

Why is skipping lunch-time insulin without replacement not advised in children with type 1 diabetes?

Answer 126

⛔ It leads to postprandial hyperglycemia and poor glycemic control ✅ Always ensure mealtime insulin coverage, either with rapid analogs or NPH as needed

Question 127

What is the risk of increasing short-acting insulin dose in the morning without lunch coverage?

Answer 127

🚨 Hypoglycemia during mid-day ⛔ Short-acting insulin has a peak effect and needs to be timed properly with meals

Question 128

What is the most practical insulin regimen for children with type 1 diabetes who want to avoid taking injections at school?

Answer 128

✅ A 3-injection regimen: ➡️ Morning: NPH + rapid-acting insulin analog ➡️ Evening: Rapid-acting insulin analog ➡️ Bedtime: Long-acting insulin (e.g., glargine)

Question 129

Which chromosomal disorder in males is characterized by tall stature, gynecomastia, small testicles, and elevated LH/FSH levels?

Answer 129

✅ Klinefelter syndrome (47,XXY)

Question 130

What genetic disorder causes intellectual disability, long face, large ears, and macroorchidism in males?

Answer 130

✅ Fragile X syndrome

Question 131

Which pituitary tumor can present with gynecomastia and galactorrhea?

Answer 131

✅ Prolactinoma

Question 132

Is breast cancer a common cause of bilateral gynecomastia in adolescent males?

Answer 132

⛔ No 🧠 Breast cancer is rare in adolescent males and usually presents unilaterally with a mass

Question 133

Which endocrine or adrenal tumors can cause gynecomastia in adolescent boys?

Answer 133

✅ CAH, Leydig cell tumors, or feminizing adrenal tumors

Question 134

What is the most likely diagnosis in a prepubertal child with lower back pain, vertebral compression fracture, decreased BMD, normal labs, and no identifiable cause of bone loss?

Answer 134

✅ Idiopathic Juvenile Osteoporosis (IJO)

Question 135

Which of the following is typically associated with high PTH and secondary osteoporosis: IJO or hyperparathyroidism?

Answer 135

✅ B) Hyperparathyroidism

Question 136

What triad defines McCune-Albright Syndrome, and what is the underlying pathophysiology?

Answer 136

✅ Triad: 1️⃣ Endocrinopathies (e.g., precocious puberty, Cushing syndrome, hyperthyroidism, acromegaly) 2️⃣ Café-au-lait macules 3️⃣ Polyostotic fibrous dysplasia (bone lesions)

Question 137

In McCune-Albright Syndrome, precocious puberty occurs with ________ levels of LH and FSH and ________ response to GnRH stimulation.

Answer 137

✅ Low LH/FSH ⛔ No response to GnRH (i.e., gonadotropin-independent precocious puberty)

Question 138

What is the key hormonal profile in Laron syndrome (GH receptor mutation)?

Answer 138

⬆️ High GH (at baseline and after stimulation) ⬇️ Low IGF-1

Question 139

Why is craniopharyngioma ⛔ NOT the cause of growth failure in Laron syndrome?

Answer 139

⛔ Craniopharyngioma causes central GH deficiency (low GH), whereas in Laron syndrome GH is elevated due to receptor resistance.

Question 140

🧠 What is the most accurate imaging modality for identifying the underlying cause of congenital hypothyroidism in a newborn with high TSH and low T4?

Answer 140

✅ Thyroid scintigraphy (technetium scan

Question 141

When is thyroid ultrasound preferred over scintigraphy in evaluating congenital hypothyroidism?

Answer 141

Thyroid ultrasound is preferred when the goal is to assess the presence or absence of thyroid tissue in its normal anatomical position, especially if scintigraphy is unavailable or contraindicated (e.g., radiation concerns).

Question 142

When is a urine catecholamine test indicated in a neonate?

Answer 142

A urine catecholamine test is indicated if there is suspicion of catecholamine-secreting tumors, such as neuroblastoma or pheochromocytoma, especially with symptoms like hypertension, sweating, pallor, or an abdominal mass.

Question 143

When is thyroid antibody testing relevant in a newborn with hypothyroidism?

Answer 143

Thyroid antibody testing is useful if maternal autoimmune thyroid disease is suspected, especially if the hypothyroidism is thought to be transient or caused by transplacental passage of maternal TSH receptor-blocking antibodies.

Question 144

إلى هُنا تنتهي رِحلتنا لهذا الشّابتر ☺️

Answer 144

والسَّلامُ عليكم ورحمة الله وبركاته 💡