Endocrine Flashcards
(246 cards)
1
Q
What is the first step in the diagnostic approach to the short child?
A
Detailed medical history (including prenatal)
A thorough medical history helps identify potential underlying causes for short stature.
2
Q
During physical examination what aspects are important in diagnosing short stature?
A
Dysmorphic features, calculation of the U/L ratio, growth velocity, bone age, target height
These aspects help in assessing the child’s growth pattern and identifying any abnormalities.
3
Q
What does the U/L ratio help to exclude in short children?
A
Disproportionate shortening e.g. skeletal dysplasia
The U/L ratio compares upper and lower segment lengths to determine if the short stature is proportionate or disproportionate.
4
Q
How do you calculate target height for boys?
A
[(father’s height (cm) + (mother’s height (cm) + 13)] divided by 2
This formula estimates the expected adult height based on parental heights.
5
Q
How do you calculate target height for girls?
A
[ (father’s height (cm) - 13) + mother’s height (cm) ] divided by 2
This formula considers the father’s height adjusted for gender differences.
6
Q
What is the significance of growth velocity in assessing short stature?
A
It is the most important tool in early detection of
abnormal growth
A consistent growth velocity can indicate normal growth patterns, while a decrease may suggest an underlying issue.
7
Q
What is the purpose of assessing bone age in children?
A
To evaluate skeletal maturity and compare it with chronological age
Discrepancies between bone age and chronological age can indicate growth disorders.
8
Q
Why is crossing percentiles on a growth chart significant?
A
It demands evaluation, even when height is still within normal range.
9
Q
What defines a child as “short”?
A
• Height below the 5th percentile
or
• More than 2 standard deviations below the mean (approximately the 2.5th percentile)
10
Q
What is the most important tool in early detection of abnormal growth?
A
Growth velocity is the most important tool.
11
Q
What does it mean when a child’s height pattern is “crossing” percentile lines?
A
It suggests a deviation from their expected growth trajectory and may indicate abnormal growth
12
Q
How frequently should accurate height measurements be taken to assess growth velocity?
A
Every 6 months.
13
Q
What defines a child as “short”?
A
Height below the 5th percentile
or
More than 2 standard deviations below the mean (approximately the 2.5th percentile).
14
Q
What is the pattern of growth velocity from birth to 3 years?
A
- Birth to 1 year: ~25 cm/year
- 1–2 years: ~12.5 cm/year.
- 2–3 years: ~8 cm/year.
1-3 y period shows growth deceleration.
15
Q
What key growth pattern occurs between 9–12 months of age?
A
Crossing percentiles toward parents’ genetics
16
Q
What is the average growth velocity from 3 years to puberty, and how is it described?
A
Around 5–6 cm/year.
Characterized by steady growth velocity during childhood.
17
Q
What happens to growth velocity during adolescence?
A
Growth velocity increases up to 15 cm/year.
This marks the return of rapid growth.
18
Q
Which sex is more commonly affected by familial short stature and constitutional growth delay?
A
- FSS: Both sexes equally affected.
- CGD: More common in boys.
19
Q
What is the birth length pattern in familial short stature and constitutional growth delay?
A
- FSS: Normal at birth, drops in percentile by age 3.
- CGD: Normal at birth, but falls below 5th percentile in the first 3 years.
20
Q
What is the typical family history and parents’ stature in FSS vs CGD?
A
- Family History:
FSS: Family history of short stature.
CGD: Family history of delayed puberty. - Parents’ Stature:
FSS: One or both parents are short.
CGD: Parents are of average height.
21
Q
How does height velocity differ between FSS and CGD?
A
FSS: Less than normal but gains >4 cm/year.
CGD: Normal height velocity.
22
Q
What is the timing of puberty in familial short stature vs constitutional growth delay?
A
FSS: Normal puberty.
CGD: Delayed puberty.
23
Q
How do bone age and chronological age compare in FSS and CGD?
A
FSS: Bone age = chronological age > height age.
CGD: Chronological age > bone age = height age.
24
Q
What is the expected final height in familial short stature and CGD?
A
FSS: Short, but within target height range.
CGD: Normal final height due to continued pre-pubertal growth.
25
What is the initial step when evaluating a short child with dysmorphic features?
Perform a karyotype and refer to a geneticist.
26
What should be investigated if the child has an abnormal upper/lower body segment ratio?
Order a radiologic skeletal survey to assess for disproportionate shortening, such as skeletal dysplasia.
27
How does obesity affect stature in children?
Obese children are usually tall, not short. A short and obese child may suggest an underlying disorder.
28
What investigations are recommended for a short child who is well-nourished or obese?
* Thyroid function tests
* Bone age X-ray
* Karyotype (especially in girls)
* Serum IGF-1 and IGFBP-3
* 24-hour urinary free cortisol if all above are normal.
29
What is Hall-Pallister syndrome and how is it related to Growth Hormone Deficiency?
Hall-Pallister syndrome is associated with GHD and includes:
* Absence of the pituitary gland
* Hypothalamic hamartoblastoma
* Post-axial polydactyly
* Congenital anomalies of the heart, lungs, and kidneys
30
What is Septo-Optic Dysplasia and how does it relate to GHD?
Septo-Optic Dysplasia is associated with GHD and involves:
* Absence of optic chiasm
* Optic nerve hypoplasia or both
It may present with visual impairment and endocrine deficiencies.
31
What are some craniofacial anomalies linked to Growth Hormone Deficiency?
* Solitary maxillary central incisors
* Cleft lip and/or palate
32
What genital abnormality may indicate Growth Hormone Deficiency in males?
Micropenis (also called microphallus), which may be a sign of congenital GHD.
33
What growth pattern is highly suggestive of Growth Hormone Deficiency?
Severely short stature (>3 SD below the mean) with decreased growth velocity (<5 cm/year).
34
What bone age pattern is typical in GHD?
**Delayed bone age** compared to chronological age and height age.
35
What are the typical IGF-1 and IGFBP-3 levels in GHD?
Both IGF-1 and IGFBP-3 are low, reflecting reduced GH action.
36
How does growth hormone impact glucose metabolism?
It can lead to insulin resistance, increasing the risk of impaired glucose tolerance or diabetes.
37
How can GH therapy affect spinal alignment?
It may worsen pre-existing scoliosis during periods of rapid growth.
38
What are the main side effects of growth hormone therapy?
* Intracranial hypertension (pseudotumor cerebri)
* Slipped capital femoral epiphysis (SCFE)
* Gynecomastia
* Worsening scoliosis
* Insulin resistance
39
What are the typical GH and IGF-1 levels in Laron’s syndrome?
* GH: High at rest and after stimulation.
* IGF-1: Low, due to inability of GH to act on the liver.
## footnote
The problem is not in producing GH but it’s in the GH receptors ( mutation )
40
What is the key definition of Diabetes Insipidus (DI)
The passage of large volumes of dilute urine with osmolality less than 300 mOsm/kg.
41
What causes Central Diabetes Insipidus?
Decreased secretion of antidiuretic hormone (ADH) from the hypothalamus or posterior pituitary.
42
What is the main mechanism in Nephrogenic Diabetes Insipidus?
Resistance to ADH action in the kidneys, leading to inability to concentrate urine.
43
What is the main difference in the underlying defect between Central and Nephrogenic Diabetes Insipidus?
* Central DI: Decreased secretion of ADH from the pituitary.
* Nephrogenic DI: Kidneys are resistant to ADH due to a defect in V2
44
What are the typical causes of Central vs. Nephrogenic DI?
* Central DI:
Idiopathic
Brain trauma or surgery
Ischemic encephalopathy
* Nephrogenic DI:
Drugs (e.g., lithium, cidofovir)
Electrolyte abnormalities (hypercalcemia, hypokalemia)
Kidney diseases (e.g., SCD, ADPKD)
Genetic V2 receptor mutation
45
What are the common clinical features of Diabetes Insipidus?
Both types:
* Polyuria
* Polydipsia (if thirst intact)
* Nocturia
46
How do serum sodium levels and response to desmopressin differ between Central and Nephrogenic DI?
* Central DI:
Serum sodium: High
Responds to desmopressin with increased urine osmolality
* Nephrogenic DI:
Serum sodium: Normal
No response to desmopressin
47
What lab findings are characteristic of Diabetes Insipidus (DI)?
* High serum osmolality (>300 mOsm/kg)
* Low urine osmolality (<300 mOsm/kg)
* Hypernatremia
* Urine specific gravity ≤ 1.005
* Urine osmolality < 200 mOsm/kg
48
49
What suggests Nephrogenic DI despite high ADH levels?
Polyuria and elevated plasma osmolality despite high basal ADH → suggests renal resistance (Nephrogenic DI).
50
What is the treatment of choice for Central Diabetes Insipidus?
Intranasal desmopressin (DDAVP) — replaces missing ADH.
51
What is the treatment of choice for Nephrogenic Diabetes Insipidus?
Thiazide diuretics — reduce polyuria by inducing mild volume depletion.
52
53
What is the pathophysiology of SIADH?
Inappropriately high ADH levels cause water retention, leading to hyponatremia, hypo-osmolality, and euvolemia or hypervolemia, with impaired water excretion.
54
What are the main causes of SIADH?
* CNS disorders: Meningitis, encephalitis, hydrocephalus, trauma
* Pulmonary diseases: Pneumonia, asthma, TB, cystic fibrosis
* Neoplastic: Leukemia, lymphoma
* Medications: Carbamazepine
55
What are key clinical features of SIADH?
* Euvolemia or hypervolemia
* Hyponatremia (symptomatic if <125 mEq/L)
* Anorexia, nausea, malaise
* Can progress to coma
56
What lab findings support the diagnosis of SIADH?
* Hyponatremia (Na+ <135 mmol/L)
* Low serum osmolality (<280 mOsm/kg)
* High urine osmolality
* Low urine output
57
What is a shared symptom between DI and SIADH?
Both may present with excessive thirst (polydipsia).
58
How is body fluid status affected in DI and SIADH?
* DI: Dehydrated, due to fluid loss
* SIADH: Overhydrated, due to fluid retention
59
What are the typical serum sodium levels in DI vs. SIADH?
* DI: Hypernatremia
* SIADH: Hyponatremia
60
How do ADH levels differ in Diabetes Insipidus vs. SIADH?
* DI: Low ADH (or ineffective in nephrogenic type)
* SIADH: Inappropriately high ADH
61
How does urinary output differ between Diabetes Insipidus and SIADH?
* DI: High urinary output
* SIADH: Low urinary output
62
What is the first-line treatment for mild SIADH?
Fluid restriction to limit water intake and correct hyponatremia.
63
When is 3% hypertonic saline used in SIADH?
In severe or symptomatic cases (e.g. seizures, coma, or Na+ < 120 mEq/L).
64
What is the recommended rate of serum sodium correction in SIADH?
0.5–1 mEq/L per hour, not exceeding 10–12 mEq in the first 24 hours.
65
What is the target sodium level when treating acute symptomatic SIADH?
Raise serum Na+ to 125–130 mEq/L to relieve symptoms, then correct slowly.
66
What is a serious complication of rapid sodium correction in SIADH?
Central Pontine Myelinolysis (CPM)
## footnote
CPM:
* A demyelinating condition of the central pons
* Occurs when serum sodium is corrected too rapidly
* Presents with dysarthria, dysphagia, paralysis, or altered consciousness
67
What is the underlying mechanism of Cerebral Salt Wasting (CSW)?
Hypersecretion of atrial natriuretic peptides leading to excessive sodium and water loss.
68
What are common neurological causes of CSW?
Head trauma, neurosurgery, hydrocephalus, brain tumors, cranial irradiation, and cerebral infarction.
69
How does volume status help differentiate CSW from SIADH?
CSW presents with hypovolemia, while SIADH presents with euvolemia or hypervolemia
70
What are key lab findings in CSW?
* Hyponatremia
* High urinary sodium
* High urine output
* Normal or high serum uric acid
71
What distinguishes CSW from DI in terms of sodium levels?
CSW causes hyponatremia, while DI leads to hypernatremia.
72
What is the treatment goal in CSW?
* Restore intravascular volume with IV fluids
* Correct sodium slowly (0.5 mEq/h, max 12 mEq/24h)
* Treat the underlying neurological cause
73
How does urine output differ between CSW and SIADH?
CSW: High urine output
SIADH: Low urine output
74
What hormone is elevated in Cerebral Salt Wasting and contributes to natriuresis?
Atrial Natriuretic Peptide (ANP) is elevated and promotes renal sodium loss.
75
What is the uric acid level typically in CSW, and how does that differ from SIADH?
In CSW, uric acid is usually normal or high, while in SIADH it’s typically low.
76
Why is CSW associated with hypovolemia despite high urine sodium?
Because excessive natriuresis leads to sodium and water loss, resulting in true volume depletion.
77
Why should sodium correction in CSW be done slowly?
To prevent Central Pontine Myelinolysis (CPM) — a dangerous demyelination syndrome from rapid correction of hyponatremia.
78
First sign of puberty in boys?
Testis > 3 mL or > 2.5 cm
79
First sign of puberty in girls?
Breast buds (thelarche)
80
When does peak growth occur in boys vs. girls?
81
* Boys: SMR 4–5 (age 13–14)
* Girls: SMR 2–3 (age 11–12)
82
When does menarche usually occur?
About 2–2.5 years after breast development
83
Do boys and girls both develop pubic hair early in puberty?
Yes
84
What are the features of SMR Stage 2 pubic hair?
Sparse, lightly pigmented, straight or slightly curled.
85
At which SMR stage does the areola form a secondary mound over the breast?
SMR Stage 4
86
What indicates SMR Stage 5 for female breast development?
Mature breast with areola becoming part of the contour, papilla projects.
87
When does penis start increasing in width and not just length?
SMR Stage 4
88
What is the pubic hair distribution in SMR Stage 5?
Adult pattern, extends to medial thigh.
89
When do testes and scrotum continue to grow but penis hasn’t thickened yet?
SMR Stage 3
90
What is the definition of precocious puberty?
Onset of secondary sexual characteristics before age 8 in girls and before age 9 in boys.
91
What is usually the first sign of puberty in girls and boys?
* Girls: Breast buds
* Boys: Testicular enlargement
92
Which hormone is useful to measure in boys with suspected precocious puberty?
Testosterone
93
Which hormone is elevated in premature pubarche in both sexes?
DHEA-S
94
How is central precocious puberty confirmed?
By elevated LH levels after GnRH stimulation test
95
What imaging is essential in evaluating boys with precocious puberty?
Brain MRI to rule out central causes.
96
What is the treatment for central precocious puberty?
GnRH analogue therapy; surgery/irradiation if a tumor is found.
97
What is the main difference in the mechanism between central and peripheral precocious puberty?
* Central (GnRH-dependent): Premature activation of GnRH pulse generator.
* Peripheral (GnRH-independent): Excess androgen or estrogen production without GnRH activation.
98
Is central precocious puberty usually idiopathic in girls or boys?
Often idiopathic in girls, but always considered pathological in boys.
99
Name common CNS causes of central precocious puberty.
* CNS tumors: astrocytoma, glioma, germ cell tumor, hypothalamic hamartoma
* CNS injury: trauma, surgery, irradiation
* Congenital: septo-optic dysplasia, arachnoid cyst, neurofibromatosis
100
What investigation is used to evaluate central precocious puberty?
* Brain MRI
* Pubertal response to LHRH (GnRH stimulation test)
101
What is the treatment for central precocious puberty?
GnRH analogues (e.g. leuprolide)
102
What are causes of peripheral precocious puberty?
* McCune-Albright Syndrome
* Testotoxicosis
* Hormone-secreting tumors
* Late-onset CAH
103
What investigations are used for peripheral precocious puberty?
* Abdominal/pelvic CT or MRI
* Prepubertal response to LHRH (no LH rise)
104
What is the treatment for peripheral precocious puberty?
Cyproterone acetate (androgen blocker)
Tamoxifen (estrogen receptor blocker)
105
What are the three classic features of McCune-Albright Syndrome (MAS)?
* Precocious puberty
* Café-au-lait spots (segmental distribution)
* Polyostotic fibrous dysplasia (PFD)
## footnote
3P ( Precocious puberty, Patches, PFD)
106
How do the café-au-lait spots in MAS differ from other conditions?
They show a segmental distribution, unlike the smooth-bordered lesions seen in neurofibromatosis.
107
What are the skeletal features of MAS?
* Multiple pathological fractures
* Visible bony deformities
* Radiographic finding: patchy areas of bony lysis
108
What hormonal pattern is typically seen in MAS-related precocious puberty?
Low LH and FSH levels due to GnRH-independent (peripheral) activation.
109
Besides puberty, what other endocrine organs can be autonomously activated in MAS?
* Thyroid → Hyperthyroidism
* Adrenal glands → Hyperadrenalism
* Pituitary → Acromegaly (via excess GH)
110
What imaging is helpful in confirming bone involvement in MAS?
Plain radiography showing multiple patchy lytic bone lesions.
111
What is the most common cause of cretinism?
Thyroid dysgenesis (aplasia, hypoplasia, or ectopic thyroid).
112
Why is congenital hypothyroidism hard to detect at birth?
Most infants are asymptomatic, and birth length/weight are usually normal.
113
What are early signs in the first month of congenital hypothyroidism?
Somnolence, poor feeding, hypotonia, and choking during feeds.
114
What physical findings may raise suspicion of congenital hypothyroidism?
Large tongue, constipation, umbilical hernia, large anterior fontanelle with open posterior, and prolonged jaundice.
115
What is the most common congenital anomaly associated with congenital hypothyroidism?
Cardiac anomalies
## footnote
ASD is the most common cardiac anomaly associated with criticism
116
What lab findings confirm congenital hypothyroidism?
High TSH and low free T4.
117
Which imaging is more effective in diagnosing thyroid anatomy in neonates?
Scintigraphy (Technetium scan) is more effective than ultrasound.
118
What is the treatment of choice and initial dose for congenital hypothyroidism?
Oral Levothyroxine, 10–15 mcg/kg/day.
119
What are the important instructions for giving levothyroxine to infants?
* Crush and mix with water or breast milk
* Do NOT use soy milk or iron/calcium with it
* If a dose is missed, double the dose next day
120
What is the prognosis if congenital hypothyroidism is treated early?
Excellent; early treatment prevents intellectual disability and neurological complications.
121
What is the most common cause of hypothyroidism in children over 6 years?
Hashimoto thyroiditis (autoimmune thyroiditis).
122
In which group is Hashimoto more common?
Girls (2–3 times more than boys), often with a positive family history of autoimmune disease.
123
What is the most common clinical presentation of Hashitoxicosis?
Goiter (usually diffuse, firm, and non-tender).
## footnote
Hashitoxicosis is Hashimotothyroiditis.
124
How does Hashimoto thyroiditis affect a child’s growth and school performance?
It causes growth retardation, fatigue, decreased school performance, and sometimes depression or cognitive issues.
125
What symptoms might make you suspect hypothyroidism in an older child?
Constipation, weight gain, cold intolerance, fatigue, and mood changes.
126
On physical exam, how can you differentiate Hashimoto thyroiditis from other thyroid conditions?
The thyroid is diffusely enlarged, firm, and non-tender; may feel lobular or nodular in 30% of cases.
127
Which lab tests confirm the diagnosis of Hashimoto thyroiditis?
Positive antithyroid antibodies:
* Anti-thyroid peroxidase (anti-TPO)
* Anti-thyroglobulin antibodies
128
Why is it important to recognize Hashimoto thyroiditis early in practice?
Early diagnosis prevents growth delay, improves cognitive and academic performance, and avoids long-term complications of untreated hypothyroidism.
129
What is the ideal treatment for Hashimoto thyroiditis (Autoimmune hypothyroidism)?
Levothyroxine (LT4) is the treatment of choice.
130
When should TSH and FT4 be rechecked after starting or adjusting Levothyroxine?
After 6–8 weeks
131
What is the half-life of Levothyroxine?
5–7 days.
132
Does persistently elevated TSH always indicate non-compliance?
No, it may reflect underdosing or recent dose changes.
133
What is the most common cause of hyperthyroidism in pediatrics?
Graves’ disease — an autoimmune condition caused by thyroid-stimulating immunoglobulins (TSI) that mimic TSH.
134
What are key clinical features of Graves’ disease in children?
* Weakness.
* Goiter.
* Weight loss, muscle wasting.
* Diarrhea, palpitations, insomnia.
* Heat intolerance.
* Stellwag sign.
## footnote
Weakness is the most common
Goiter can cause dysphagia
135
What is Stellwag sign?
Mild exophthalmos, eyelid retraction, infrequent blinking
136
What lab findings support the diagnosis of Graves’ disease?
* High free T4 and T3
* Low TSH
* Positive TSI (confirms diagnosis)
* Anti-TPO antibodies may also be present
137
What is the most common side effect and the which is the most serious one of Methimazole?
* Transient urticarial rash (most common)
* Agranulocytosis ( most serious and more common in elderly)
138
What is hypoparathyroidism?
A condition caused by deficiency of parathyroid hormone (PTH), leading to hypocalcemia.
139
What are common causes of hypoparathyroidism?
* Accidental removal of parathyroid glands during neck surgery
* Congenital causes (e.g., DiGeorge syndrome)
* Metabolic disorders like Wilson disease and hemochromatosis
140
What are typical clinical features of hypoparathyroidism?
* Paresthesias (especially perioral, fingers, toes)
* Hyperirritability, muscle cramps
* Seizures (even in known epilepsy)
* Laryngospasm causing hoarseness
141
How do you differentiate primary hypoparathyroidism from pseudohypoparathyroidism?
* Primary hypoparathyroidism:
* Low PTH, low calcium
* Pseudohypoparathyroidism:
* High PTH (resistance at receptor level), low calcium
142
What is the most common cause of primary hyperparathyroidism in children?
A single parathyroid adenoma.
143
What are some conditions associated with familial hyperparathyroidism?
MEN 1 and MEN 2A syndromes.
144
What are secondary causes of hyperparathyroidism in children?
* Chronic renal failure
* Cholestatic liver disease
* Medications like lithium
145
What are typical symptoms of hyperparathyroidism?
* Often asymptomatic
* Muscle weakness, bone pain
* Abdominal pain, pancreatitis
* Nephrolithiasis
146
What lab findings suggest hyperparathyroidism?
* High calcium (>12 mg/dL)
* Low phosphorus (<3 mg/dL)
* High PTH
147
What is the treatment for primary hyperparathyroidism in children?
Subtotal or total parathyroidectomy.
148
How is acute severe hypercalcemia (Ca >14 mg/dL) managed?
* IV hydration
* Loop diuretics (e.g. furosemide) after hydration
* Hemodialysis if needed
149
What is the most common cause of Cushing syndrome in infants?
Functioning adrenocortical tumor.
150
What are the most characteristic clinical signs of Cushing syndrome in children?
* Moon face, buffalo hump, central obesity
* Growth failure / short stature
* Purple striae, easy bruising
* Hypertension, osteopenia/fractures
151
What is the best initial diagnostic test for Cushing syndrome?
24-hour urine free cortisol
152
What are common lab findings in Cushing syndrome?
* Leukocytosis
* Hyperglycemia
* Hypokalemic metabolic alkalosis
153
When is brain MRI indicated in a child with suspected Cushing syndrome?
When pituitary tumor is suspected.
154
What is the treatment of choice for a unilateral adrenal tumor causing Cushing syndrome?
Unilateral adrenalectomy
155
What is the treatment of choice for pituitary adenoma in Cushing disease?
Transsphenoidal pituitary microsurgery
156
What is the most common cause of Addison disease in children?
Autoimmune adrenalitis,
## footnote
especially in females
157
Name autoimmune conditions commonly associated with Addison disease.
* Type 1 diabetes
* Celiac disease
* Hashimoto thyroiditis / Graves disease
158
What are the classic electrolyte findings in Addison disease?
* Hyponatremia
* Hyperkalemia
159
What skin sign is typical in chronic Addison disease? What is its cause?
Hyperpigmentation, due to high ACTH levels.
160
What is the best initial test for suspected adrenal insufficiency?
Serum cortisol level
161
What test confirms adrenal insufficiency?
Rapid ACTH stimulation test (Synacthen)
162
What is the treatment for chronic adrenal insufficiency?
* Hydrocortisone 9-12 mg/m²/day (oral)
* Fludrocortisone 0.1-0.2 mg/day if salt-wasting
163
What is the emergency management during adrenal crisis or vomiting?
* Triple the usual hydrocortisone dose for fever/illness
* Hydrocortisone IM if vomiting or shock
164
What can cause acute adrenal crisis in a known Addison patient?
* Missed stress dose during illness or surgery
* Adrenal hemorrhage (e.g., meningococcemia)
165
Weight change in Addison vs. Cushing?
* Addison → Weight loss
* Cushing → Weight gain, especially face & trunk
166
Skin signs in Addison vs. Cushing?
* Addison → Hyperpigmentation
* Cushing → Purple striae, thin skin, easy bruising
167
Blood pressure in Addison vs. Cushing?
* Addison → Hypotension
* Cushing → Hypertension
168
ACTH level in Addison vs. Cushing?
* Addison → High ACTH (primary)
* Cushing → High or low, depends on cause (pituitary, ectopic, adrenal)
169
Cortisol level in Addison vs. Cushing?
* Addison → Low cortisol
* Cushing → High cortisol
170
Electrolyte disturbance in Addison vs. Cushing?
* Addison → Hyponatremia + Hyperkalemia
* Cushing → Hypokalemic metabolic alkalosis
171
Best initial test in Addison and cushing?
* Addison → Serum cortisol
* Cushing → 24h urinary free cortisol
172
Bone findings in Addison and cushing.?
* Addison → May have normal or ↓ bone mass
* Cushing → Osteoporosis, fractures
173
Main treatment of Addison and Cushing?
* Addison → Hydrocortisone + Fludrocortisone
* Cushing → Depends on cause (e.g., surgery for tumor)
174
What is the likely diagnosis in a boy with adrenal insufficiency and progressive neurologic symptoms (e.g. ataxia, vision/hearing loss)?
Adrenoleukodystrophy (X-linked)
175
What is the pathophysiology of Adrenoleukodystrophy?
Accumulation of very long chain fatty acids in the adrenal glands and CNS.
176
What are key features of Adrenoleukodystrophy?
* X-linked (affects boys)
* Adrenal insufficiency → hyperpigmentation
* Neurologic symptoms: ataxia, vision/hearing loss
* MRI: Periventricular demyelination
177
What are keywords that help identify Adrenoleukodystrophy in exams?
* Boy + adrenal insufficiency + neurologic decline
* Very long chain fatty acids
* MRI: demyelination
## footnote
TTT will be supportive.
178
What is the most common cause of ambiguous genitalia in a female newborn?
Congenital Adrenal Hyperplasia (CAH)
179
What is the most common cause of ambiguous genitalia in a male newborn?
Androgen Insensitivity Syndrome (AIS)
180
How does CAH typically cause ambiguous genitalia in females?
Excess androgens → virilization of external genitalia
181
Why do males with Androgen Insensitivity Syndrome appear with ambiguous or female external genitalia?
End-organ resistance to androgens despite normal or high androgen levels
182
What is the most common cause of ambiguous genitalia in females?
21-hydroxylase deficiency
## footnote
It is the most common enzyme deficiency in CAH.
183
What is the inheritance pattern of CAH?
Autosomal recessive
184
What lab value is diagnostic for 21-hydroxylase deficiency?
↑↑ 17-hydroxyprogesterone >1000 ng/dL
## footnote
Search for 17 first, it gives sign of 21
185
What are the electrolyte disturbances in salt-wasting CAH?
Hyponatremia, hyperkalemia, hypoglycemia
186
Why does hyperpigmentation occur in CAH?
Due to ↑ ACTH (stimulates melanocytes)
## footnote
* In CAH, there’s a deficiency in cortisol production.
* Cortisol normally gives negative feedback to the hypothalamus and pituitary.
* When cortisol is low → the pituitary compensates by increasing ACTH secretion.
* ACTH is derived from the same precursor as melanocyte-stimulating hormone (MSH) → both come from POMC (Pro-opiomelanocortin).
* So, when ACTH levels rise, MSH also increases → this stimulates melanocytes in the skin to produce more melanin.
* Result: Generalized hyperpigmentation, especially in skin creases, nipples, and mucous membranes.
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How is CAH diagnosed prenatally?
Molecular testing from chorionic villus (10 wks) or amniocentesis (18 wks)
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What is the first-line treatment during adrenal crisis?
IV fluids + IV dextrose + IV hydrocortisone (50-100 mg/m²)
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What is the maintenance therapy for CAH?
Oral hydrocortisone + fludrocortisone (if mineralocorticoid deficient)
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What is the stress-dose adjustment of steroids during illness?
Triple the daily oral dose
191
Which CAH type causes HTN and virilization?
11β-hydroxylase deficiency
## footnote
(due to accumulation of 11-deoxycorticosterone, which has mineralocorticoid effect).
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Which CAH type causes hypertension and hypokalemia with sexual infantilism?
17α-hydroxylase deficiency
## footnote
(due to excess mineralocorticoids, but ↓ androgens).
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What is the classic triad of symptoms in salt-wasting 21-hydroxylase deficiency?
1. Ambiguous genitalia (in females)
2. Hyponatremia
3. Hyperkalemia
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What is the hormonal pattern in 21-hydroxylase deficiency?
• ↓ Cortisol
• ↓ Aldosterone (in salt-wasting form)
• ↑ ACTH
• ↑ 17-hydroxyprogesterone
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Which CAH type is associated with ambiguous genitalia in both sexes and salt-wasting?
3β-hydroxysteroid dehydrogenase deficiency
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How do you differentiate 21-hydroxylase deficiency from 11β-hydroxylase deficiency?
• 21-OH deficiency: No hypertension
• 11β-OH deficiency: Hypertension present due to DOC accumulation
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What is the underlying mechanism of CAH vs. Precocious Puberty?
• CAH: Enzyme deficiency → adrenal hormone imbalance (↑ androgens).
• PP: Early activation of HPG axis (central) or excess sex steroids (peripheral).
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What is the sex hormone pattern in CAH vs. Central Precocious Puberty?
• CAH: ↑ Androgens, but low LH/FSH (prepubertal response to GnRH).
• CPP: ↑ LH/FSH (pubertal response to GnRH stimulation).
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What is the bone age status in CAH, Precocious Puberty?
Advanced bone age in both conditions.
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Is CAH a gonadotropin-dependent or independent process?
• CAH: Gonadotropin-independent (Peripheral PP).
• CPP: Gonadotropin-dependent (Central PP).
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What test confirms Central Precocious Puberty?
GnRH stimulation test → pubertal LH response (↑↑ LH after stimulation).
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What lab finding is key for diagnosing CAH?
↑ 17-hydroxyprogesterone (>1000 ng/dL).
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What clinical feature can appear in both CAH and Precocious Puberty?
Early pubic/axillary hair, but in CAH it’s due to adrenal androgens; in PP it’s due to true puberty.
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What’s the treatment approach difference between CAH, CPP?
• CAH: Hydrocortisone ± fludrocortisone
• CPP: GnRH analogues
205
What is gynecomastia?
Benign enlargement of male breast tissue due to glandular proliferation, often bilateral.
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What is pseudogynecomastia?
Fat deposition in the breast without glandular tissue proliferation (seen in obesity).
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What’s the most common cause of gynecomastia in adolescents?
Physiologic pubertal gynecomastia
## footnote
Due to transient estrogen-testosterone imbalance.
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When is gynecomastia considered pathological?
• If breast size >5 cm (macromastia)
• Tender, progressive, recent onset
• Hard or fixed mass
• Associated lymphadenopathy
## footnote
Red flags 🚩
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What are causes of gynecomastia?
• Klinefelter syndrome
• Testicular tumors
• Adrenal or germ cell tumors (ectopic HCG)
• Drug-induced or endocrine disorders
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How to manage pubertal gynecomastia?
Observe and re-evaluate in 6 months; no treatment usually needed as it resolves in 90% within 3 years.
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When should you investigate further for gynecomastia ?
If symptoms are atypical, persistent, progressive, or associated with systemic signs.
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What HLA types are associated with the highest risk of T1DM?
HLA-DR3 and DR4
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What are the autoimmune markers for diagnosing T1DM?
• Glutamic acid decarboxylase (GAD) antibodies
• Islet cell antibodies
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What are the classic symptoms of Type 1 DM?
• Polydipsia
• Polyuria
• Weight loss
• Hyperglycemia, glycosuria
• May present with ketoacidosis
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What are the diagnostic criteria for diabetes?
• FPG ≥ 126 mg/dL
• Random glucose ≥ 200 mg/dL + symptoms
• 2-hour OGTT ≥ 200 mg/dL
• HbA1c ≥ 6.5%
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What insulin regimens are used in T1DM?
• Basal: long-acting insulin (glargine, detemir)
• Bolus: rapid-acting insulin (lispro, aspart, glulisine) before meals
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What’s the target HbA1c in pediatric T1DM patients?
Less than 7.5%
218
What conditions are commonly associated with T1DM?
• Autoimmune hypothyroidism
• Celiac disease
219
What routine monitoring is needed for T1DM?
• HbA1c every 3 months
• Microalbuminuria (after 5 years)
• Eye exam (after 5 years)
• TSH every 1–2 years
## footnote
HA1c every 3m as thee half life of RBCs is 3m.
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What viral infections are associated with increased risk of T1DM?
• Enteroviral infections
• Congenital rubella
221
Does breastfeeding have a role in prevention of T1DM?
Yes, breastfeeding is protective and associated with lower risk.
222
What is the risk of T1DM in siblings or children of a patient?
Around 4–6% risk in first-degree relatives.
223
When do we suspect ketoacidosis in a child with T1DM?
• Vomiting
• Abdominal pain
• Kussmaul breathing
• Fruity breath
• Altered mental status
(Especially in undiagnosed cases or missed insulin)
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What is the first-line treatment of Diabetic Ketoacidosis (DKA)?
1. IV fluids (0.9% NS) for rehydration
2. IV insulin (regular) after fluids
3. Correct electrolytes (especially potassium!)
4. Monitor for cerebral edema (risk in kids!)
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When do we start screening 🔎 for complications in T1DM?
• After 5 years of diagnosis
## footnote
Screening includes eye exam, microalbuminuria, lipid profile, and TSH
226
What are the red flags 🚩 in poor T1DM control?
• Frequent hypoglycemia
• HbA1c > 9%
• Growth delay
• Delayed puberty
• Recurrent DKA episodes
227
9-year-old female with type 1 DM presents with abdominal pain and weight loss — what is the best screening test?
Tissue transglutaminase IgA antibodies (tTG-IgA) to screen for celiac disease.
## footnote
Why?
• Celiac disease is a common autoimmune comorbidity in children with type 1 diabetes.
• Symptoms like abdominal pain, weight loss, and sometimes growth failure raise suspicion.
• tTG-IgA is the most sensitive and specific screening test.
Bonus Tip:
Also check total serum IgA (to rule out IgA deficiency which can give false negatives).
228
What is Diabetic Ketoacidosis (DKA)?
A serious complication of insulin deficiency causing metabolic acidosis, hyperglycemia, and dehydration.
229
What is the most common cause of death in DKA?
Cerebral edema
230
What are the main precipitating factors of DKA?
• Infection
• Insulin omission
• Illness or stress without insulin adjustment
231
Diagnostic criteria for DKA?
• Blood glucose > 200 mg/dL
• pH < 7.30
• Bicarbonate < 15 mmol/L
232
How is the severity of DKA classified?
• Mild: pH 7.21–7.30, HCO₃⁻ 11–15
• Moderate: pH 7.11–7.20, HCO₃⁻ 6–10
• Severe: pH < 7.10, HCO₃⁻ < 5
233
Risk factors for cerebral edema in DKA?
• Young age
• Bicarbonate therapy
• Rapid/overaggressive fluids
• Early insulin administration
234
Clinical signs of cerebral edema in DKA?
• Headache, vomiting, drowsiness
• Altered mental status
• Inappropriate bradycardia
• Diastolic BP > 90 mmHg
• Age-inappropriate incontinence
235
Treatment of cerebral edema in DKA?
Mannitol IV or 3% hypertonic saline
236
What is the first step in the management of DKA?
Fluid resuscitation with 0.9% Normal Saline (10cc/kg IV over 1 hour).
237
What is the fluid composition used for rehydration after the first hour in DKA?
• 0.9% NS
• +20 mEq/L KPhos
• +20 mEq/L K Acetate
Given at maintenance + deficit rate over 48 hours.
238
When should the IV fluids be changed to include dextrose?
When blood glucose reaches 250–300 mg/dL.
239
What fluids should be given once glucose drops to 250–300 mg/dL?
D5 0.45% NS + 40 mEq/L (KPhos + KCl), at the same previous rate.
240
What is the recommended insulin dose in DKA?
IV insulin at 0.1 units/kg/hour.
241
When should IV insulin be discontinued?
When the patient tolerates oral intake and is transitioned to subcutaneous (SC) insulin.
242
What are the criteria for resolution of DKA?
• pH > 7.3
• Bicarbonate > 15
243
What should be done if blood glucose falls below 150 mg/dL and the patient is still acidotic?
• Use 10% dextrose
• Continue IV insulin
• Decrease insulin rate if hypoglycemia persists despite max dextrose
244
What symptoms in infants should raise suspicion for diabetes mellitus or DKA?
• Persistent vomiting
• Polyuria (increased wet diapers)
• Recurrent or persistent candidal diaper rash
• Oral thrush (not resolving with routine care)
245
Why is persistent candidal rash concerning in an infant?
It may be a sign of underlying immunosuppression or hyperglycemia, especially in early-onset Type 1 DM or DKA.
246
What’s the next step if an infant presents with vomiting, polyuria, and candidal rash?
• Check random blood glucose
• Consider urine ketones
• Evaluate for DKA if clinical suspicion is high
