Topics for Residents and Medical Students

Pediatric Endocrinology Cases

Welcome to Pediatric Endocrinology! Hopefully, these cases will help you familiarize yourself with some common Pediatric Endocrinology topics. We have included some suggested readings for each topic. During your rotation, please complete 2 cases per week and we will discuss them together.

Included cases:

1)Thyroid disorders

2)Diabetes

3)Adrenal disorders

4)Disorders of sexual differentiation

5)Obesity

6)Short Stature

7)Precocious puberty

8)Delayed puberty

Thyroid Disorders

CASE #1:

You receive a call from the state lab regarding an abnormal thyroid screening test on a now 6 day old female.

Questions:

1)What different methods are used for thyroid screening on newborn metabolic tests? What are the advantages/disadvantages of each?

2)What historical questions are important to know about this infant and mom?

3)You find that this infant was a healthy and born at term. Mom had an unremarkable pregnancy and delivery and has no known history of thyroid disorders. Review of the NBS results reveals low T4 and TSH over 100. Knowing that this infant has an abnormal newborn metabolic screen, what do you do next?

4)You examine the infant in the clinic the next morning. What are some possible signs and symptoms of congenital hypothyroidism?

5)Her confirmatory labs return quite abnormal with a high TSH and low FT4. As you do not have Peds Endo at your hospital, you begin levothyroxine 10-15 mcg/kg/day and consult Peds Endo at a nearby hospital. How do you give this medication? What do you tell the family about the medication? When do you re-check labs? What is your treatment goal?

6)The family would like to know the causes of congenital hypothyroidism. They would like to have other children and wonder if this is genetic. What do you tell them?

7)At 6 months, the infant remains on a small dose of Synthroid and the family has read that hypothyroidism can often be transient and therefore they would like to stop the medication now. What do you tell them?

Suggested Readings:

1)Update of newborn screening and therapy for congenital hypothyroidism.
Pediatrics. 2006 Jun;117(6):2290-303

2)Hypothyroidism. Pediatrics in Review. 2004 March; 25 (3): 94-100

CASE #2:

You are evaluating a 14 yr old female for concerns of ADHD. During the appointment, you note that the patient is very fidgety, tachycardiac, & has lost weight since last year. You are concerned about hyperthyroidism.

1)What questions would you ask her to help determine if she may indeed have hyperthyroidism?

2)As you proceed through her physical exam, list some of the potential findings in a patient with hyperthyroidism.

3)After completing her history and PE, you are still concerned that she has hyperthyroidism and plan to order lab testing. What is the differential diagnosis of hyperthyroidism? Which one is most likely in this patient?

4)What initial thyroid labs would you order? What other studies may be helpful?

5)She is diagnosed with Graves disease and you arrange for Peds Endo evaluation the next week. She is started on a beta-blocker to control her symptoms until the appt. The family wants to know some of the possible treatments. Briefly, what are the main treatment options for Graves?

Suggested Readings:

Clinical review 99: The management of Graves' disease in children, with special emphasis on radioiodine treatment. J Clin Endocrinol Metab. 1998 Nov;83(11):3767-76

Diabetes case

A 13 year old female presents to her primary care physician with a two week history of polyuria, polydipsia and a 9 pound weight loss.

What is the most likely diagnosis?

The astute physician is worried about diabetes and orders a finger stick glucose, which comes back at 591. What other labs would you order and what are the abnormalities that you might find in a diabetic patient?

The patient has a pH of 7.36, a CO2 of 23 and mild urine and serum ketone levels. Her CBC is normal and the rest of the labs are not back. What is the diagnostic criteria for diabetes?

The following day, she asks the hospitalist "Why did I get diabetes?" Discuss the risk factors for developing type 1 diabetes.

The patient was initially given a fluid bolus of 20 cc/kg and then started on maintenance IV fluids. Additionally, in the PICU she was started on an insulin drip at 0.1 units/kg/hr.

She is closely monitored and labs followed. How do you decide when it is time to discontinue to insulin drip?

Later she is transitioned to subcutaneous insulin with Lantus and Novolog. What is the duration of action for these types of insulin and how might you create an insulin regimen?

Prior to discharge a follow-up appointment is scheduled with a pediatric endocrinologist. How often should this patient check her blood sugar at home and what should she aim for?

Suggested Readings:

“Care of Children and Adolescents with type 1 diabetes”. Diabetes Care. Jan 2005.

ADA Position Statement. "Standards of Medical Care in Diabetes - 2007." Diabetes Care. 2007 Jan;30 Suppl 1:S4-S41.

Adeghate E. et. al. "An Update on the Etiology and Epidemiology of Diabetes Mellitus." Annals of the NY Academy of Sciences. 2006 Nov. 1084 (1), 1–29.

Daneman Denis. "Type 1 Diabetes." Lancet. 2006 Mar. Vol 367 (847-58).

Kaufman FR. "Type 1 Diabetes Mellitus." Pediatrics in Review. 2003 Sep. Vol 24. No. 9. (291-300)

Adrenal disorder case

While on-call, you receive a phone call about an abnormal newborn screen for CAH. You review the record and find that this is a term infant boy born 4 days ago. If he has CAH, what is the most likely enzyme deficiency?

You read that 75% of patient with CAH are salt-wasters. Discuss the classification scheme for 21-OH deficiency CAH.

If this baby had been a girl, what would be the typical presentation of 21-OH deficiency?

You bring in the patient for further evaluation and lab testing. His 17-OH progesterone and electrolytes are still pending. What are the classic lab findings in CAH? At what age, do boys with CAH typically present with salt-losing crisis?

His 17-OHP is 9,500ng/dL and he is diagnosed with 21-OH deficiency. In consultation with Pediatric Endocrinology, he is started on Hydrocortisone, Florinef, and salt supplementation. He is seen regularly by both you and Pediatric Endocrinology and has done very well. However, at 6 months of age, he has his first febrile illness with URI symptoms. Mom calls you to confirm what she should do. What counseling do you give her regarding treatment for his mild febrile illness?

Unfortunately, later that night you received a page from the intern in the emergency room. Your patient has a fever to 102, vomited up his last dose of hydrocortisone, and is “less active” than usual according to the mother. What treatment advice do you provide the ER intern as you prepare to go evaluate your patient? What are potential signs and symptoms of acute adrenal insufficiency (crisis)?

Suggested Readings:

1) “Congenital adrenal hyperplasia” Lancet. 2005 Jun 18-24;365(9477):2125-36

2) Speiser PW. “Congenital Adrenal Hyperplasia” NEJM. 21 Aug 2003.

3) Consensus statement on 21-hydroxylase deficiency from the Lawson Wilkins Pediatric Endocrine Society and the European Society for Paediatric Endocrinology.

J Clin Endocrinol Metab. 2002 Sep;87(9):4048-53

Disorder of sexual differentiation cases

You are called to the newborn nursery to evaluate a term, newborn infant with ambiguous genitalia.

Questions:

What do you say to the parents? What should you avoid saying?

What history would you want to obtain from the parents?

Infants with ambiguous genitalia can be categorized as: 1) 46XY Disorder of Sexual Development (undervirilized male) or 2) 46XX DSD (overvirlized females). What is the most common etiology for 46XX DSD? What is the most common etiology for 46XY DSD?

What exam features would you look for to help determine if the newborn is more likely an undervirilized male or an overvirilized female?

On exam, you find an otherwise well appearing term infant in no acute distress. Only significant physical findings are found on genital exam: phallus (1.5cm in length, 2cm width), hypospadias at base of penis, bifid scrotum that are pigmented with rugae, suspected bilateral gonads in scrotum. What defines ‘microphallus’ in a term infant? By what gestational age should a testicle be located in the scrotum?

What is your differential diagnosis?

What sub-specialists should you consult at this time?

In discussion with your consultants a few baseline tests are requested. What initial lab tests and/or radiologic tests may be helpful?

Your patient is evaluated is ultimately diagnosed with partial androgen insensitivity.

Suggested Readings:

1)“Evaluation of the newborn with developmental anomalies of the external genitalia. American Academy of Pediatrics. Committee on Genetics” Pediatrics. 2000 Jul;106(1 Pt 1):138-42.

2)“Early Assessment of Ambiguous Genitalia” Arch Dis Child. 2004 May;89(5):401-7.

3) Hughes et al. “Consensus statement on management of intersex disorders”. Arch

Dis Child. 2006

OBESITY CASES

1)Janice is an eight year old girl who comes to clinic for evaluation of cough. Her illness began one week with coryza and low grade temperature, but although the coryza has resolved she has continued to cough. Her mother is concerned that she may need antibiotics. On further questioning she has had no fever since the first day of her illness and her cough is dry and non-productive and does not appear to be a significant problem. However, on PE you note that her weight is 95 pounds (greater than the 97% for age) and her height is 54 ½ inches (at the 95% for age).

Questions:

Do you address her weight at this visit?

What other questions do you want to ask in her past medical history and ROS?

Are there any family history questions of relevance?

What are the important things to note on PE?

How likely is Janice to remain overweight? What are the variable that might help to determine this?

What recommendations would you make to her and her family?

How would you follow her?

2) Peter is a 6 month old here for a well baby appt. The pregnancy was unremarkable except slight IUGR with a birth weight of 5 lbs 1 oz at term. No other medical or social issues. His developmental milestones are normal. His weight is now at 95% and length at 75% His mother is very overweight. She says she weighs 175# and is 5’2”, but you believe this may be an underestimate of her current weight. His father weighs 195# with a height of 5’7”.

Is weight likely to be an issue for this child? Why or why not?

How would you approach this question with the family?

3) Evelyn is a 16 year old who was sent by her PCM to the cardiology clinic (where you are rotating) for evaluation of hypertension. She claims that she is totally healthy, and her blood pressure was noted incidentally to be high when she came to the clinic for her pre-college physical exam. The blood pressure noted on her chart from that visit is 155/94. You also note from her record that she weighs 187 pounds and is 5’3” tall.

Do you:

Refer her to endocrinology for TFTs
Refer her directly to nutrition
Give her to the medical student to evaluate
Apply for allergy fellowship
Other? If so, what??

The best overall current, comprehensive, but relatively brief reference on pediatric obesity is the Supplement to Pediatrics from December 2007.

Assessment of Child and Adolescent Overweight and Obesity, Pediatrics 120: S163-288 (2007)

Short Stature Case

You are seeing a 3 y/o female whose parents are concerned about her growth. You plot her height and weight for today’s visit and she is currently <3% for both height and weight. What historical questions are important?

As a part of your complete physical exam, you plot out her growth chart and calculate a growth velocity over the past year since her 2 yr well baby exam.

What is a normal growth velocity? How does it vary through childhood?

After plotting her growth curve, you note that her weight was falling off the curve prior to her height. What would some of your concerns be at this point?

Instead if you determined that her she is falling away from her height curve but maintaining her weight, what would be on your differential?

Finally, how might you interpret her growth if her height and weight have been tracking just below 3%?

What one study can be very helpful in the evaluation of short stature especially if you are considering normal variants of growth in your DDx? Also, list some potentially useful labs for evaluation of short stature.

Two causes of healthy but short children are familial short stature and constitutional delay. Define these and how you would diagnose each one.

Your patient has physical exam features suggestive of Turner syndrome. List some of the physical exam findings in TS including as a newborn.

What cardiac abnormalities are found in Turner’s?

If your patient had not been diagnosed prior to puberty, what is the typical presentation of a girl with Turner syndrome during adolescence?

Suggested Readings:

A General Pediatric Approach to Evaluating a Short Child. Pediatrics in Review. Nov 2005

Care of girls and women with Turner syndrome: A guideline of the Turner Syndrome Study Group. J Clin Endocrinol Metab. Jan 2007.

Turner Syndrome: Diagnosis and Management. Am Fam Physician 2007

Precocious puberty

Case #1

15 month old female with bilateral breast development noted at well child exam. You suspect premature thelarche. What would make you confirm or refute your diagnosis?

Premature adrenarche is another normal variant of early puberty. It is more likely to occur in girls and more often in AAs. List the other expected findings in benign premature adrenarche.

Case #2

Your next well child exam is a 6 yr old female who also has bilateral breast development. Her mother reports that the breast budding started approximately 6 months ago. She also has noted a few dark pubic hairs over the past month. You are appropriately concerned about precocious puberty. What age defines precocious puberty in girls? In boys?

You complete a full history and exam and find that this girl is otherwise healthy, but has Tanner 2 breasts and pubic hair. Additionally, she has grown 4.5 cm in the past 6 months. What laboratory and radiologic evaluation would you pursue at this time?

Ultimately, she is diagnosed with idiopathic central precocious puberty. Discuss central versus peripheral precocious puberty.

Suggested Readings:

1) “Precocious Puberty” Pediatrics in Review 2006 Oct;27(10):373-81.

2) “A practical approach to precocious puberty” Clinical Pediatrics. 2007 May;46(4):299-306.

3) Merke et al. “Evaluation and management of precocious puberty” Arch Dis Child. 1996 Oct; 269-271.

4) “Precocious puberty: Who has it? Who should be treated?” J Clin Endocrinol Metab. 1999 Feb;84(2):411-4.

Delayed Puberty

A 13 and 1/2 year old female presents to your clinic without any signs of puberty. Mom is concerned that most of the girls in her class are already having their periods and knows that something must be wrong.

What is the first sign of puberty in females and does this girl meet the criteria for delayed puberty?

If this was a 13 year old boy presenting without any signs of puberty, would you be as concerned?

Having determined that this young lady does warrant further evaluation, you obtain more history and perform a physical exam. She is an only child and was adopted at 4 months of age. She is growing at the 5th percentile for height and the 10th percentile for weight. She has no pubic or axillary hair and no breast development.

Discuss the differential diagnosis for delayed puberty (in either gender).

You obtain a bone age to help in the differential diagnosis. According to your Greulich and Pyle, her bone age is somewhere between 10 and 11.

Does this change your differential diagnosis?

What is the next step in your evaluation of this young lady?

Ultimately, you diagnosis her with constitutional delay of puberty based on delayed bone age, pre-pubertal LH & FSH and 46XX karyotype. Her mother asks if there is any treatment as the patient is very distraught about her delayed puberty. What do you tell her?