Pediatric Examination and Board Review (73 page)

9.
(A)
Adrenoleukodystrophy. The presence of X-linked adrenoleukodystrophy needs to be ruled out in any young man with primary adrenal insufficiency. Not all patients have neurologic symptoms when the adrenal insufficiency is diagnosed. Very long-chain fatty acid concentrations are increased in affected males. If a patient is diagnosed with adrenoleukodystrophy, all male siblings should be screened.

10.
(E)
All of the above. Adrenal hemorrhage in children has been associated with
Pseudomonas aeruginosa
sepsis, meningococcemia and
E coli
sepsis (Waterhouse-Friderichsen syndrome), and in neonates following a difficult labor or asphyxia. Patients may have a sudden fall in hemoglobin with hyponatremia and hyperkalemia.

11.
(B)
Autoimmune adrenalitis. Autoimmune adrenalitis accounts for greater than 70% of cases of Addison disease. The most common detectable antibody is against 21-hydroxylase. Autoimmune destruction of other endocrine glands is often seen. In the past, infectious adrenalitis caused by tuberculosis was the most common cause of Addison disease, but now infectious adrenalitis occurs in less than 20% of new cases of Addison disease. Adrenal insufficiency occurs at a low incidence in metastatic cancer because a significant proportion of the adrenal gland must be destroyed for adrenal insufficiency to become evident.

12.
(A)
Serum cortisol concentrations are highest in the early morning. There is a diurnal rhythm of serum cortisol, and concentrations are typically highest in the early morning between 4 and 8 AM. In patients with normal adrenal function, cortisol levels typically increase markedly with stress.

13.
(E)
He should be discharged on glucocorticoid and fludrocortisone. Patients with Addison disease are deficient in both glucocorticoid and mineralocorticoid and thus need daily replacement of both. The importance of diligence taking the medications needs to be stressed to avoid adrenal crisis. Patients with secondary or tertiary adrenal insufficiency typically only need treatment with hydrocortisone because ACTH is not an important regulator of aldosterone release.

14.
(C)
He should double his hydrocortisone dose. The major risk to the patient with primary adrenal insufficiency is the lack of an appropriate adrenal response to stress. Thus patients who are ill or undergoing any type of procedure should be treated with additional glucocorticoid. The dose of mineralocorticoid is typically not adjusted during illness. If patients are unable to keep down the medications and fluids, they need to come to the emergency department for IV therapy to avert an adrenal crisis. It is important that patients with adrenal insufficiency wear a MedicAlert tag.

15.
(A)
Poor compliance with the glucocorticoid regimen. Darkening of the skin pigmentation in a patient with primary adrenal insufficiency would suggest that treatment with glucocorticoids is not adequate and ACTH levels are elevated. Either the child has outgrown the glucocorticoid dose and will need an adjustment or, more commonly in an adolescent, they have not been as compliant as desired.

16.
(B)
Autoimmune adrenalitis. Secondary adrenal insufficiency is caused by any process that affects the pituitary gland and interferes with ACTH secretion. Autoimmune adrenalitis is a disorder of the adrenal gland and causes primary adrenal insufficiency. Isolated ACTH deficiency is rare. Megestrol acetate is a progestin with some glucocorticoid activity that is used in children with cancer or cystic fibrosis to increase appetite. Withdrawal of megestrol acetate can be associated with secondary adrenal insufficiency in some patients.

17.
(B)
Hyperkalemia can occur. Hyponatremia can be seen in secondary adrenal insufficiency because glucocorticoid action is required for appropriate renal free water clearance. However, hyperkalemia does not occur because the renin-angiotensin-aldosterone system remains intact. Hyperpigmentation of the skin occurs typically only in primary adrenal insufficiency.

18.
(E)
Chronic administration of high doses of glucocorticoid. With the widespread use of supraphysiologic doses of glucocorticoids, suppression of the hypothalamic-pituitary-adrenal axis is a frequent cause of adrenal insufficiency in children. Tertiary adrenal insufficiency can be seen with prolonged use of high-dose glucocorticoids (>7 days), and the timing of recovery of hypothalamic-pituitaryadrenal function can be variable. Glucocorticoids should never be discontinued abruptly in patients who have been on a prolonged course but rather should be weaned slowly.

S
UGGESTED
R
EADING

Bethin KE, Muglia LJ. Adrenal insufficiency. In: Radovick S, MacGillivray MH, eds.
Pediatric Endocrinology
,
A Practical Clinical Guide
. Totowa, NJ: Humana Press; 2003:203-226.

Brenner K, Frohna JG. Index of suspicion. Case 3. Diagnosis: acute adrenal insufficiency.
Pediatr Rev.
2001;22:245-250.

Miller WL, Achermann JC, Fluck CE. The adrenal cortex. In: Sperling MA, ed.
Pediatric Endocrinology.
3rd ed. Philadelphia, PA: WB Saunders; 2008:444-511.

Chapter 6

GASTROENTEROLOGY

CASE 46: A 1-MONTH-OLD WITH JAUNDICE

A 1-month-old boy is brought to your office for a routine checkup. The baby was born at full term and his birthweight was 4.1 kg. His mother had routine prenatal care and no complications during the pregnancy. The child is exclusively breast-fed and was first noted to be jaundiced at 3 days of age. His bilirubin peaked on day of life 6 and then began to decrease. Mom reports he has “always been yellow.” She denies irritability, fever, vomiting, or diarrhea. She reports that the child eats well and has yellow seedy stools each time he feeds.

On physical examination, the child’s weight is 5 kg. He is in no apparent distress. He has jaundiced skin and icteric sclera. His cardiac and respiratory systems are unremarkable. His abdomen is nondistended with normal bowel sounds. His liver is palpable 2 cm below the right costal margin and his spleen tip is palpable. The remainder of his examination is unremarkable.

SELECT THE ONE BEST ANSWER

1.
The first laboratory test indicated in the evaluation of this patient is

(A) conjugated bilirubin

(B) blood culture

(C) hepatic function test

(D) none; because of earlier bilirubin testing, no further testing is necessary

(E) complete blood count (CBC)

2.
Below are results for this child’s laboratory evaluation

Which entity is least likely in the differential diagnosis?

(A) biliary atresia

(B) Alagille syndrome

(C) choledochal cyst

(D) congenitally acquired hepatitis B

(E) neonatal hepatitis

3.
The additional immediate evaluation for this child should include

(A) ultrasound, α
₁
-antitrypsin level, urine reducing substance, urine culture

(B) hepatitis B surface antigen, hepatitis C antibody, toxoplasmosis, rubella, cytomegalovirus, herpes simplex, ie the so-called TORCH titers

(C) serum amino acids and urine organic acids

(D) thyroid-stimulating hormone (TSH) and a sweat test

(E) all of the above

4.
If this patient had an ultrasound that demonstrated a choledochal cyst, the next step in management is to

(A) call interventional radiology for drainage of the cyst

(B) do nothing; most cysts resolve spontaneously

(C) consult a surgeon because complete resection of cyst is necessary

(D) treat conservatively with ursodiol

(E) monitor yearly hepatic function panels

5.
If this child had a history of vomiting and no red reflex on ophthalmologic examination, the first thing you would do is

(A) check amino acids levels

(B) check an ammonia (NH
₃
) level

(C) have mother stop breast-feeding the child

(D) consult ophthalmology

(E) stop giving the infant protein

6.
If the child from question 5 has a fever and looks ill, then this child is at significant risk for

(A) liver failure

(B)
Escherichia coli
sepsis

(C) group B streptococcal sepsis

(D)
Listeria
infection

(E) all of the above

7.
If the child has laboratory results as outlined in question 2 and a sibling had a similar presentation in infancy, this child’s possible diagnoses include