Q1.

An 8-month-old infant presents with the primary complaint of

irritability. He has been exclusively breastfed since birth. His mother was
not interested in providing any supplemental foods because her milk
supply has been adequate. Physical examination reveals a fussy infant
who has frontal bossing and whose weight and height are both at the 25th
percentile. The infant becomes irritable with movement of the left arm.
Arm radiography reveals a humeral fracture and bowing of both radii.
Chest radiography demonstrates enlargement of the costochondral
junctions.

Of the following, the MOST likely diagnosis is

A. congenital syphilis
B. osteogenesis imperfecta
C. vitamin D-deficient rickets
D. vitamin D-resistant rickets
E. vitamin E deficiency

Q2. You are evaluating an 8-week-old infant whose birthweight was 1,000
g and who was delivered at 30 weeks gestation. He experienced early
respiratory distress and sepsis, but now these problems have resolved,
and he recently progressed from parenteral nutrition to full enteral
feedings. Of the following, the feeding that will provide the BEST mineral
content to ensure healthy bone development for this infant is

A. cow milk-based infant formula

B. human milk
C. premature formula
D. protein hydrolysate formula
E. soy protein-based formula

Q3. You are addressing a group of new mothers regarding infant feeding.
One asks you when an infant can be switched from formula to whole cow
milk.

Of the following, you are MOST likely to respond that whole cow milk

A. can be introduced at 6 months of age if an infant has significant

gastroesophageal reflux
B. can be given at 9 months of age if the infant is also taking a wide
variety of supplemental
foods
C. may be given as a supplement at any age as long as the infant also
receives human milk
D. should be avoided until 12 months of age because its iron content is
absorbed poorly
E. should be avoided until 2 years of age because its caloric content is
inadequate for optimal
growth
Q4. A 2-week-old infant presents to the emergency department with a 1-
day history of decreased feeding, pallor, diaphoresis, and increasing
somnolence. He was born at term, and the delivery was uncomplicated.
On physical examination, his heart rate is 190 beats/min, his respiratory
rate is 80 breaths/min, his blood pressure is 50/30 mm Hg, and his
extremities are cool and pale with poor pulses. You place the infant on a
cardiorespiratory monitor and begin your assessment and management.

Of the following, the MOST appropriate pair of tests to consider in this

child is

A. complete blood count and bone scan

B. electrocardiography and echocardiography
C. electroencephalography and head ultrasonography
D. lumbar puncture and head computed tomography scan
E. serum electrolytes and chest computed tomography scan

Q5. You are urgently called to the newborn nursery to evaluate a 3-day-old
term male infant who is lethargic. The baby was taking formula well for
the first 2 days but vomited after his last 2 feedings and has become
increasingly difficult to arouse. A review of the record reveals that he was
born at 36 weeks gestation to a 30-year-old gravida 2, now para 2
woman. The mother is
Rh-negative and received Rh immune globulin during the pregnancy.
Pregnancy, labor, and delivery were uneventful; Apgar scores were 8 and
9 at 1 and 5 minutes. Family history is noncontributory. On physical
examination, the baby appears well developed, is very jaundiced, and has
hypotonia and tachypnea. He responds with a grimace to sternal rubbing
but does not arouse to voice or to touch. Findings on abdominal
examination are normal. You order a series of laboratory tests, start
intravenous fluids, and arrange for transfer to the neonatal intensive care
unit. A laboratory technician subsequently notifies you of some critical
laboratory values, including a platelet count of 35x103/mcL (35x109/L),
serum carbon dioxide of 4 mEq/L (4 mmol/L), anion gap of 28 mEq/L (28
mmol/L), serum ammonia of 250 mcmol/L, and total bilirubin of 20 mg/dL
(342 mcmol/L). There are large ketones in the urine.

Of the following, the MOST likely diagnosis is

A. bilirubin encephalopathy
B. citrullinemia
C. hypoxic-ischemic encephalopathy
D. propionic acidemia
E. transient hyperammonemia of the newborn
Q6. During the health supervision visit of a 5-year-old girl, you notice
pubic hair (Sexual Maturity Rating 3). Her height is at the 75th percentile
and weight is at the 95th percentile. She has no acne or clitoromegaly. Her
mother tells you the girl developed an adult body odor around 8 months
ago, and the mother noticed the pubic hair about 6 months ago. She adds
that the pubic hair is a little more noticeable now than when she first saw
it.

Of the following, the MOST important initial screening study is

A. bone age radiograph

B. measurement of dehydroepiandrosterone sulfate (DHEA-S)
C. measurement of 17-hydroxyprogesterone
D. measurement of testosterone
E. pelvic and abdominal ultrasonography

Q7. The parents of a 15-year-old boy previously diagnosed as having

constitutional delay of growth and puberty are concerned that their son is
being bullied by his 10th-grade classmates. His grades have declined from
As to Bs, and he says he dislikes school. He has been in good health, and
he eats and exercises in moderation. On physical examination, his height
and weight are at the 10th percentile, and his genitalia are at Sexual
Maturity Rating 1. When you speak to the boy in private, he becomes
tearful, complaining that he is afraid to change for gym and that his
friends no longer wish to be with him. He and his parents ask for your
advice in this situation.

Of the following, the BEST response is to

A. offer reassurance and arrange for follow-up evaluation in your office in

6 months
B. recommend caloric supplements
C. refer the family for behavioral counseling
D. refer the boy for a psychoeducational evaluation
E. refer the boy to an endocrinologist for re-evaluation and possible
hormonal therapy

Q8. A 16-year-old girl presents to the clinic with a 6-day history of low-
grade fever and cough. On physical examination, she has a temperature
of 100.6F (38.1C) and widespread crackles throughout her lung fields.
You believe she has a walking pneumonia caused by Mycoplasma
pneumoniae.

Of the following, the MOST accurate method used to establish the

diagnosis is

A. polymerase chain reaction

B. serum cold agglutinins
C. serum Mycoplasma titers
D. sputum culture
E. sputum Gram stain

Q9. You are evaluating a 12-year-old girl who has a 1-month history of
daily fevers (up to 104F [40C]), cervical adenopathy, severe malaise,
headache, and lower back pain. She lives at home with her parents and
two sisters, all of whom have been well. She has a 5-year-old cat and two
birds for pets. Six months ago, she spent 2 weeks visiting relatives who
live on a ranch in Mexico where she learned to milk the cows, feed the
pigs and chickens, and ride horses. She also sampled the local cuisine.
Physical examination reveals a febrile, tired-appearing girl who is having
rigors. She has diffuse 1 x 1-cm nontender cervical adenopathy, with
splenomegaly and tenderness to palpation of her lower back. Her white
blood cell count is 4.9x103/mcL (4.9x109/L) with 31% polymorphonuclear
leukocytes, 15% band forms, 48% lymphocytes, and 6% monocytes;
erythrocyte sedimentation rate is 70 mm/hr; and C-reactive protein
concentration is 6.8 mg/dL.

Of the following, the MOST likely diagnosis is

A. brucellosis
B. cat-scratch disease
C. Epstein-Barr virus mononucleosis
D. leptospirosis
E. toxocariasis

10.A male infant who is experiencing failure to thrive and hypernatremic

dehydration is admitted to the hospital. After administration of
intravenous fluids, euvolemia is restored and the serum sodium is
normalized to 140 mEq/L (140 mmol/L). A water deprivation test results in
a 5% loss of body weight over 4 hours and an increase in serum sodium
concentration to 145 mEq/L (145 mmol/L) and serum osmolality to 310
mOsm/kg (310 mmol/kg). Simultaneous urine osmolality is 50 mOsm/kg
(50 mmol/kg). Subcutaneous administration of desmopressin does not
reduce urine output or increase urine osmolality. You decide to place the
infant on a formula that possesses a low renal solute load.

Of the following, the statement that BEST describes the properties of

infant formulas as they relate to renal solute load is that
A. human milk has a greater renal solute load than do cow milk-based
formulas
B. the carbohydrate composition of the formula increases the renal solute
load
C. the fat composition of infant formulas more greatly alters the renal
solute load when the
medium-chain triglycerides component is increased
D. the primary minerals involved in renal solute load are sodium,
potassium, chloride, and
phosphorus
E. the protein composition of the formula has no effect on renal solute
load

11. A 10-year-old African-American boy presents to your office

complaining of a 12-month history of stomach pain, nausea, bloating, and
diarrhea that occurs 45 to 60 minutes after eating dairy foods. He states
that his symptoms occur only when he eats too much. He denies
emesis, hematochezia, or pruritus associated with these episodes. On
physical examination, the boy appears healthy and has normal vital signs.
His abdomen is soft and has normal bowel sounds, and results of a stool
guaiac test are negative.

Of the following, the MOST likely cause for this boys symptoms is

A. allergic eosinophilic gastroenteritis

B. lactose intolerance
C. milk protein allergy
D. milk protein enterocolitis
E. oral allergy syndrome

12. A 2-year-old boy is brought to the emergency department after his

father found the boy in the garage gagging, coughing, and drooling
profusely. His parents report that he had opened a number of containers,
but they are unable to recall the names of the products. On physical
examination, the boy is awake and crying, his heart rate is 160 beats/min,
his respiratory rate is 24 breaths/min, he has clear lung sounds, and his
blood pressure is 100/60 mm Hg. He has reactive, mid-sized pupils and
white eschars on his tongue and soft palate. Shortly after his examination,
he begins to vomit.

Of the following, the MOST likely cause of this patients symptoms is

A. antifreeze
B. drain cleaner
C. gasoline
D. glyphosophate weed killer
E. organophosphate insecticide

13. You are evaluating a 4-year-old girl who has a 2-day history of perineal
pruritus and dysuria. There is no history of trauma or sexual abuse.
Physical examination reveals Sexual Maturity Rating 1 genitalia, with
erythema of the labia majora, labia minora, and vaginal introitus. The
hymenal tissue appears normal, and there is no vaginal discharge.

Of the following, the MOST appropriate management is

A. administration of fluconazole orally

B. administration of mebendazole orally
C. examination under anesthesia for vaginal foreign body
D. report to child protective services for sexual abuse
E. sitz baths followed by the application of an emollient

14. You are examining a 12-week-old infant who was born at 28 weeks
gestation, developed necrotizing enterocolitis 7 days after birth, and
underwent a bowel resection of 20 cm of ileum. The baby has been
dependent on parenteral nutrition since shortly after birth and has
cholestasis due to the parenteral nutrition. Attempts to feed her with a
cow milk-based formula have resulted in diarrhea. Stool analysis
demonstrates 0.25% (trace) reducing substances and 3+ fecal fat.

Of the following, the intervention that is MOST likely to decrease the

infants diarrhea is

A. addition of a vitamin supplement to the formula

B. addition of ranitidine to the formula
C. increase in the protein content of the formula
D. use of a formula that has a high medium-chain triglyceride content
E. use of a formula that has a lower concentration of carbohydrates

15. A term infant is delivered by emergency cesarean section following

the acute onset of maternal vaginal bleeding and profound fetal
bradycardia. The Apgar scores are 1, 2, and 3 at 1, 5, and 10 minutes,
respectively. Resuscitation includes intubation and assisted ventilation,
chest compressions, and intravenous epinephrine. The infant is admitted
to the neonatal intensive care unit and has seizures 6 hours after birth.

Of the following, a TRUE statement about other organ-system injury that

may occur in the infant is that

A. cardiovascular injury is uncommon

B. hypoxic-ischemic encephalopathy usually is an isolated condition
C. liver injury may result in a coagulopathy
D. most infants who have seizures develop cerebral palsy
E. necrotizing enterocolitis does not occur in term infants

16.A medical student rotating in your clinic tells you about a 5-month-old
infant he has evaluated. He reports that the infant is fed goat milk
exclusively and asks you if this is adequate nutrition at this age.

Of the following, the MOST likely deficiency in this infant is of

A. folate
B. iron
C. niacin
D. vitamin A
E. vitamin D

17. You are seeing a 4-year-old boy for a health supervision visit prior to
enrollment in preschool. His mother expresses some concerns about his
speech articulation, although he uses many words. Results of his physical
examination, including pneumatic otoscopy, are normal, as are results of
tympanometry. Routine screening audiometry in your office, despite a
cooperative child and a quiet examination room, yields equivocal results.

Of the following, the BEST next step in the evaluation of this childs
hearing is

A. assessment for hearing aid placement

B. reassurance that the child will grow out of it
C. referral to an audiologist
D. referral to an otolaryngologist
E. sedated auditory brainstem evoked potentials

18. Yesterday, you received a call from the newborn nursery that they
were referring to you a term infant who was being discharged at 4 days of
age. The female newborns birthweight was 3.3 kg and the delivery was
by repeat cesarean section. Findings on physical examination at
discharge, including heart rate, respiratory rate, and blood pressure, were
normal. Her lungs were clear, and no murmurs were noted. She was
breastfeeding without difficulty. Today, her mother calls to tell you that
she is difficult to awaken, pale, and breathing much more rapidly than she
was in the hospital nursery. She has had one wet diaper in the last 12
hours. When you meet them in the emergency department, you note that
the infant has cool extremities, weak pulses, and lethargy.
Of the following, the MOST likely cause of this newborns condition is

A. aortic coarctation
B. atrioventricular septal (canal) defect
C. tetralogy of Fallot
D. transposition of the great arteries
E. ventricular septal defect

19. A 14-year-old girl who has a 1-year history of migraine headaches

presents to the emergency department with a severe headache that she
calls the worst headache of my life. The headache occurred suddenly
after she lifted a heavy box. Her mother says that the girl has been
holding her head stiffly. On physical examination, she appears in severe
pain and has meningismus. Other findings on the physical examination
are normal.

Of the following, the MOST appropriate initial course of action is

A. emergent noncontrast head computed tomography scan

B. intravenous administration of ceftriaxone
C. intravenous administration of dihydroergotamine
D. lumbar puncture
E. oral administration of sumatriptan

20. You care for a newborn who has Down syndrome due to an unbalanced
14;21 translocation. At the request of the cytogenetics laboratory director,
you arranged for the parents blood to be collected and karyotyped. You
now are notified that the babys mother has an unusual karyotype with a
balanced 14;21 translocation. You plan to refer her for genetic counseling.

Of the following, the recurrence risk for having a baby who has Down
syndrome in a future pregnancy for this woman is CLOSEST to

A. 1% added to her age-related risk

B. 15%
C. 30%
D. 50%
E. 100%

21. A 15-year-old girl comes to your office because she never has had a
menstrual period. She has no chronic illnesses and is active playing
softball once a week. Her mother and sister both had menarche at age 13
years. On physical examination, she is at the 15th percentile for height
and weight and has no hirsutism or acne, no breast development, and
Sexual Maturity Rating 3 pubic hair development.

Of the following, the MOST appropriate initial laboratory evaluations are

A. antiovarian antibody and antithyroid antibody concentrations

B. follicle-stimulating hormone concentration and karyotype
C. progesterone and 17-hydroxyprogesterone concentrations
D. testosterone and androstenedione concentrations
E. thyroid-stimulating hormone and thyroxine concentrations

22. You are seeing a 10-year-old girl for her yearly health supervision visit.
On physical examination, you palpate a smooth and symmetric thyroid
that seems twice normal size. There are no palpable nodules. Serum free
thyroxine and thyroid-stimulating hormone (TSH) values are both normal.
Serum thyroperoxidase antibody concentrations are elevated.

Of the following, the initial BEST approach to management is to

A. obtain a 123-I thyroid scan

B. obtain thyroid ultrasonography
C. recheck TSH concentration in 6 months
D. start treatment with triiodothyronine
E. start treatment with TSH

23. A 7-year-old girl is being treated with a gonadotropin-releasing

hormone agonist by an endocrinologist for precocious puberty. On physical
examination, she is at Sexual Maturity Rating 3. Her parents are pleased
with the medical treatment, but are concerned that their daughter is
having problems fitting in with the 7-year-old girls with whom she used to
play, who
are teasing her. She is now gravitating toward playing with older children
in her neighborhood. The parents ask for guidance regarding their
daughters behavior.

Of the following, your BEST response to their concerns is to

A. explain that having older friends is beneficial to her self-esteem and

should be encouraged
B. explain that their daughter should be treated more maturely because
her body is maturing at a faster rate
C. recommend psychological counseling to help the girl deal with her
feelings regarding the changes in her body
D. suggest that her parents call the girls playmates and tell them to stop
teasing her
E. suggest that the parents get a pet for their daughter so she will spend
less time with the neighborhood children

24. A 6-year-old boy presents to the clinic with a 2-day history of fever and
noisy breathing. His mother is concerned because she feels that her son is
going to die. His past medical history is unremarkable, but he has not
yet received his fifth diphtheria-tetanus-acellular pertussis (DTaP) or his
second measles-mumps-rubella (MMR) vaccination. On physical
examination, the boy
appears scared and toxic and has labored respirations and a very harsh
cough. He is not drooling and can lie flat while you examine him. His
temperature is 103.5F (39.7C), respiratory rate is 35 breaths/min, heart
rate is 168 beats/min, and blood pressure is 107/68 mm Hg. Although he
has tachypnea, his lungs are clear to auscultation, he has no heart
murmur, and findings on his abdominal examination are benign.

Of the following, the MOST likely diagnosis is

A. bacterial tracheitis
B. bronchitis
C. epiglottitis
D. foreign body aspiration
E. laryngotracheobronchitis

25. You are speaking to the pediatric ward nurses regarding prevention of
the nosocomial spread of rotavirus disease after three patients developed
the disease while hospitalized. You stress the importance of good
handwashing practices.

Of the following, the MOST appropriate additional statement regarding

transmission-based precautions for rotavirus is that health-care personnel
who have patient contact

A. do not need to take transmission-based precautions

B. need to put on gloves before entering patient rooms
C. need to put on gowns and gloves before entering patient rooms
D. need to put on gowns, gloves, and mask before entering patient rooms
E. need to put on gowns, gloves, mask, and shoe covers before entering
patient rooms
26. You are asked to evaluate a 3,500-g term infant who was found to
have unilateral renal agenesis on prenatal ultrasonography. Laboratory
tests reveal a sodium concentration of 140 mEq/L (140 mmol/L),
potassium of 4.1 mEq/L (4.1 mmol/L), chloride of 110 mEq/L (110 mmol/L),
and
bicarbonate of 19 mEq/L (19 mmol/L).

Of the following, the serum bicarbonate value can be explained BEST by

A. a normal value for age

B. an inborn error of metabolism
C. renal compensation for primary respiratory alkalosis
D. renal tubular acidosis
E. stool losses of bicarbonate resulting in metabolic acidosis

27. A 9-year-old boy who has a history of asthma and allergic rhinitis
presents with coughing, wheezing, and chest tightness of 4 days
duration. He only has 1 week of school left before summer break, but his
parents have kept him home because they are administering a beta-2
agonist inhaler every 4 hours to control his symptoms. They mention that
everyone was sick in his class, and he developed clear rhinorrhea and a
temperature of 99.0F (37.3C) at the start of his current illness.

Of the following, the MOST likely causative virus is

A. coronavirus
B. influenza virus
C. parainfluenza virus
D. respiratory syncytial virus
E. rhinovirus

28. A 2-year-old boy is brought to the emergency department because of

moderate respiratory distress. History reveals that he was born at 25
weeks gestation and had bronchopulmonary dysplasia. He has had
rhinorrhea and cough for the past 2 days, and this morning he developed
retractions and wheezing that were unresponsive to albuterol. His usual
medications include
albuterol and oxygen at 1 L/min by nasal cannula to maintain his oxygen
saturation at 93%. On physical examination, his heart rate is 160
beats/min, respiratory rate is 60 breaths/min, and oxygen saturation is
82%. You place him on 100% oxygen using a nonrebreather mask and
obtain blood gases, which reveal a pH of 7.35, Pco2 of 70 mm Hg, Po2 of
226 mm Hg, and HCO3 of 35 mEq/L (35 mmol/L). As you are interpreting
the blood gases, the nurse notifies you that the boy has developed apnea.
Of the following, the MOST likely explanation for his sudden deterioration
is

A. acute pulmonary embolus with increased arterial-alveolar gradient

B. elimination of respiratory drive by correction of chronic hypoxemia
C. respiratory muscle fatigue due to acute metabolic acidosis
D. severe bronchospasm with acute respiratory acidosis
E. spontaneous pneumothorax with acute hypoxemia

29. A 10-week-old infant has undergone abdominal surgery for

gastroschisis. After 6 weeks of parenteral nutrition (PN), cholestasis has
developed.

Of the following, the intervention that is MOST likely to reduce the severity
of cholestatic liver disease due to PN is

A. addition of 800 IU of alpha-tocopherol (vitamin E) to the daily PN

B. early introduction of hypocaloric (trophic) enteral feeding
C. elimination of intravenous long-chain triglyceride supplementation
D. reduction of the dextrose concentration of the PN to 15% (15 g/100 mL)
E. removal of branched-chain amino acids from the PN

30. You are evaluating a 3-day-old preterm infant who was born at 26
weeks gestation and weighed 800 g. Her blood pressure has dropped
acutely, and she has developed seizures. Physical examination
demonstrates equal mechanical breath sounds, no heart murmur,
hypotonia, a bulging anterior fontanelle, and lethargy. Laboratory
evaluation reveals anemia, metabolic acidemia, and hyperglycemia.

Of the following, the MOST likely explanation for these findings is

A. acute pneumothorax
B. intracranial hemorrhage
C. late-onset sepsis
D. patent ductus arteriosus
E. perinatal asphyxia

31. During the prenatal visit with new parents, a mother expresses
concern about regulating the temperature of the bath water for the new
baby. You tell her that standards regarding hot water heaters have been
determined.

Of the following, the temperature that has been determined to be

appropriate for hot water heaters is CLOSEST to

A. 110F
B. 120F
C. 130F
D. 140F
E. 150F

32. A 7-year-old child who has autism presents with purulent, bloody
discharge from the ear of 1 days duration. His mother is unaware of any
antecedent events. The child is unable to provide any history, but his
mother explains that he is attending day camp. Examination of the
affected ear reveals blood-tinged, purulent discharge that prohibits
visualization of the tympanic membrane and apparent tenderness to
touch of the pinna.

Of the following, the MOST appropriate next step is to

A. lavage the ear in an attempt to examine the tympanic membrane

B. prescribe oral trimethoprim-sulfamethoxazole
C. prescribe topical fluoroquinolone solution
D. prescribe topical tobramycin
E. refer the patient immediately to an otolaryngologist

33. A 1-week-old infant presents to the emergency department with a 1-

day history of poor feeding, pallor, diaphoresis, and increasing
somnolence. She was born at term, and the delivery was uncomplicated.
On physical examination, her heart rate is 180 beats/min, respiratory rate
is 90 breaths/min, and blood pressure is 50/30 mm Hg. Her breath sounds
are shallow, and cardiac evaluation reveals no murmurs but a gallop
rhythm. Her liver is palpable at 3 cm below the costal margin. Her
extremities are cool, pale, and mottled, and she has poor distal pulses.
After you administer normal saline at 20 mL/kg, her heart rate is 194
beats/min.

Of the following, the MOST appropriate next step is

A. adenosine infusion at 50 mcg/kg
B. computed tomography scan of the head
C. dopamine infusion at 10 mcg/kg per minute
D. lumbar puncture followed by antibiotics
E. normal saline infusion at 20 mL/kg

34. A 10-year-old boy presents with leg weakness that has progressed
over 24 hours, bladder and bowel incontinence, and back pain. There is no
history of trauma. On physical examination, leg reflexes are diminished,
and there is numbness in the legs and lower trunk. Rectal examination
demonstrates decreased tone. Sensory examination shows absent
pinprick sensation below T6.

Of the following, the MOST appropriate initial diagnostic test is

A. brain magnetic resonance imaging with contrast

B. electromyography of the legs
C. lumbar puncture
D. nerve conduction velocities
E. spine magnetic resonance imaging with contrast

35. A 16-year-old girl comes to your office with a 2-day history of

moderate pelvic pain. She is sexually active and using no contraception.
She has had a scant yellowish-white discharge from her vagina, but no
vaginal itching. On physical examination, she is afebrile, has a heart rate
of 95 beats/min and a blood pressure of 110/75 mm Hg. Bowel sounds are
of normal pitch and frequency. She has no rebound or guarding on
abdominal evaluation, but has moderate pelvic tenderness to palpation.
She has no costovertebral angle tenderness. Findings on pelvic
examination include scant yellow cervical discharge, a friable inflamed
cervix, cervical motion tenderness, and mild uterine tenderness but no
adnexal masses. Results of her pregnancy test are negative, and findings
on urinalysis are normal.

Of the following, the MOST appropriate next step is

A. C-reactive protein measurement

B. endometrial biopsy
C. laparoscopy
D. pelvic computed tomography scan
E. testing for gonorrhea and chlamydia

36. A 1-year-old boy presents with generalized seizures. His general

physical examination findings are normal except for a prominently positive
Chvostek response. Results of laboratory studies include total serum
calcium of 4.5 mg/dL (1.1 mmol/L) and phosphorus of 8.2 mg/dL (2.73
mmol/L). Blood urea nitrogen and creatinine values are normal for age.

Of the following, the MOST likely diagnosis is

A. dietary calcium deficiency

B. hypoparathyroidism
C. hyperphosphatasia
D. vitamin D deficiency rickets
E. vitamin D-resistant rickets

37. The parents of a 12-year-old boy are concerned about his changing
behavior. He was previously a straight A student, but now he is getting Cs
in most of his classes. He no longer wants to be with his friends after
school, and he recently quit the basketball team. On weekends, he sleeps
much of the day, and when awake, he stays alone in his room. Findings on
his physical examination are normal. He appears apathetic and speaks
softly in a monotone.

Of the following, your MOST appropriate next step is to

A. evaluate him for attention-deficit/hyperactivity disorder

B. recommend that he rejoin his basketball team
C. refer him for educational evaluation
D. refer him for mental health evaluation
E. schedule a follow-up evaluation in 1 month

38. You are treating a 2-year-old girl who has suspected meningococcal
bacteremia and meningitis. Over the past 2 hours, she has required
multiple fluid boluses and inotropic support to help maintain her blood
pressure. She has been intubated due to respiratory failure. Her
temperature is 96F (35.6C), and she is covered in a petechial and
purpuric rash (Item Q44). Her most recent laboratory results reveal a
white blood cell count of 1.2x103/mcL (1.2x109/L) with 80% lymphocytes,
10% neutrophils, and 10% band forms and a platelet count of 32x103/mcL
(32x109/L).

Of the following, the MOST important additional laboratory test is

A. erythrocyte sedimentation rate

B. measurement of creatine kinase
C. measurement of fibrinogen
D. measurement of lactic acid
E. review of peripheral blood smear

39. A 6-year-old child presents for a health supervision visit. On physical

examination, his weight is 18 kg, height is 102 cm (<3rd percentile),pulse
rate is 90 beats/min, respiratory rate is 18 breaths/min, and blood
pressure is 134/88 mm Hg. Of note, he has pale conjunctivae and mild
edema. Among the results of laboratory evaluation are:
Hemoglobin, 7.5 g/dL (75 g/L)
White blood cell count, 6.0 x103/mcL (6.0 x109/L)
Platelet count, 275x103/mcL (275x109/L)
Mean cell volume, 82 fL
Reticulocyte count, 0.4% (0.004)
Blood urea nitrogen, 94 mg/dL (33.6 mmol/L)
Serum creatinine, 12.1 mg/dL (1,070 mcmol/L)
The stool is negative for occult blood.

Of the following, the MOST likely explanation for this patients anemia is

A. chronic gastrointestinal blood loss

B. erythropoietin deficiency
C. folic acid deficiency
D. hemolysis
E. iron deficiency

40. You are working with a medical student in an outpatient pediatric

clinic. His first case is a 4- month-old male infant who has a 4-day history
of rhinorrhea, coughing, and tachypnea. On physical examination, the
infant is fussy and has a temperature of 99.2F (37.4C), pulse rate of 110
beats/min, respiratory rate of 60 breaths/min, and pulse oximetry of 92%
on room air. On
auscultation, expiratory wheezes are audible in all lung fields. You discuss
the differential diagnosis and ask the student what he knows about
respiratory syncytial virus (RSV) bronchiolitis.

Of the following, the MOST accurate statement regarding RSV bronchiolitis

is that

A. household pets can be colonized with RSV and may act as reservoirs for
transmission to
family members
B. most chest radiographs of infants hospitalized for RSV bronchiolitis
appear normal
C. most infants who develop RSV bronchiolitis require hospitalization
D. recurrent wheezing may occur for several years after mild or severe
RSV bronchiolitis
E. the initial RSV infection usually occurs in school-age children

41. A mother brings in her 5-year-old son in for a health supervision visit.
Family history reveals that the boys father has had a soft-tissue sarcoma
and a colectomy for colon polyps. Results of the boys physical
examination are within normal limits. The mother asks if her son is at
increased risk for polyps and cancer. You review the fathers medical
records, which indicate that his colectomy was performed at age 20
because of the discovery of 50 adenomas in the colon.

Of the following, the BEST recommendation for the son at this time is

A. a colonoscopy to survey for polyps

B. annual fecal occult blood testing
C. annual screening of serum alpha-fetoprotein
D. genetic testing to determine his risk
E. ultrasonography for testicular tumors

42. You are conducting prenatal counseling with a 30-year-old mother of

two healthy children. She is 34 weeks pregnant and asks you about
potential newborn problems for her soon-to-be delivered infant, reminding
you that her last child was treated for early-onset group B streptococcal
(GBS) infection.

Of the following, your MOST likely reply is that

A. antibiotic treatment during pregnancy will eradicate maternal GBS

B. both the mother and her newborn will require treatment
C. intrapartum chemoprophylaxis is indicated
D. previous GBS infection has no bearing on this pregnancy
E. urinary tract infection with GBS is uncommon

43. You are seeing 16-year-old twin brothers for health supervision visits.
They tell you that they plan to spend most of the summer boating and
fishing at their camp on the lake.
Of the following, the advice that is MOST likely to decrease their risk of a
boating-related fatality is to

A. conduct regularly scheduled engine maintenance

B. have both boys take swimming lessons before the summer
C. install a carbon monoxide detector on the boat
D. post the phone number to the United States Coast Guard on the boat
E. wear life jackets at all times while on the boat

44. You care for a 6-month-old boy who was born with pulmonary atresia
and ventricular septal defect. He received a modified Blalock-Taussig
(systemic-to-pulmonary artery) shunt 5 days after birth. His oxygen
saturations have ranged between 70% and 84% at office visits over the
past 2 months. During a health supervision visit, you record a hematocrit
of 57% (0.57).

Of the following, this childs polycythemia puts him at INCREASED risk for

A. acute leukemia
B. bacteremia
C. cerebrovascular accident
D. congestive heart failure
E. necrotizing enterocolitis

45. You are called to the nursery to evaluate a newborn who has
respiratory distress. On observation, the baby appears pink while crying
but becomes dusky when calm. You note a hypoplastic nose and
depressed nasal bridge on physical examination. A review of her chest
radiographs reveals stippling of the vertebrae.

Of the following, the MOST likely teratogen to cause these findings is

A. alcohol
B. hydantoin
C. retinoic acid
D. valproic acid
E. warfarin

46. A 15-year-old boy comes to your office for a sports physical

examination. Compared with when you saw him at his 10-year-old health
supervision visit, he has progressed from Sexual Maturity Rating 1 to 4.

Of the following, the laboratory value that is MOST likely to have changed
is
A. calcium
B. hemoglobin
C. platelet count
D. serum albumin
E. white blood cell count

47. A 12-year-old girl is receiving learning support because of difficulty

with reading and language arts. She struggles to do well in the classroom
but realizes she can never compete successfully with her older sister
academically. She is well-coordinated and enjoys playing basketball in her
yard. Her parents are concerned by her negative comments about herself
and ask your advice on how they can help her improve her self-image.

Of the following, your BEST recommendation is to

A. evaluate the girl for attention-deficit/hyperactivity disorder

B. recommend extracurricular activities for the girl
C. repeat the psychoeducational evaluation
D. suggest that her older sister help with her homework
E. suggest the parents hire an educational advocate

48. A 12-year-old boy who has a history of Hodgkin disease presents to

the emergency department with fever, headache, and malaise of 4 hours
duration. He has not received any cancer treatment in more than 1 year.
His immunizations are up to date, including the 23-valent pneumococcal,
Haemophilus influenzae type b, and polysaccharide meningococcal
vaccines. He has had a splenectomy. He currently takes oral penicillin
twice daily. Physical examination reveals a toxic-appearing boy who has a
temperature of 104F (40C), heart rate of 110 beats/min, respiratory rate
of 30 breaths/min, and a blood pressure of 118/76 mm Hg. No other
findings on the physical examination suggest the source of his fever.

Of the following, the MOST likely cause of his fever is infection with
A. Haemophilus influenzae type b
B. Pseudomonas aeruginosa
C. Staphylococcus aureus
D. Streptococcus pneumoniae
E. Streptococcus pyogenes

49. You are evaluating a 6-year-old boy who has a 2-day history of fever
(102F [38.9C]), headache, vomiting, moderate crampy periumbilical
pain, and watery diarrheal stools (six to eight a day) that have become
blood-streaked in the last 12 hours. He just returned yesterday from a 3-
week visit
to his grandparents farm in India. Physical examination reveals a tired
boy who has a temperature of 102.5F (39.2C), tacky mucous
membranes, and dry lips. He has diffuse abdominal tenderness to
palpation that is most pronounced in the periumbilical area andassociated
with some voluntary guarding but no rebound. Laboratory tests show a
peripheral white blood cell count of 9.0 x103/mcL (9.0x109/L) with 60%
polymorphonuclear leukocytes, 5% band forms, 30% lymphocytes, and
5% monocytes. A test for the presence of fecal leukocytes is positive. You
suspect Campylobacter sp as the cause of this patients condition.

Of the following, the laboratory condition that is REQUIRED to isolate this

organism is

A. aerobic culture conditions

B. antibiotic-free culture media
C. blood agar media
D. incubation temperature of 35C
E. incubation temperature of 42C

50. A 1-year-old year boy who has chronic kidney disease from posterior
urethral valves presents to your office because his breathing has been
noisy for the past 2 hours. His usual medications include calcium
carbonate and vitamin D. On physical examination, you note inspiratory
stridor. He has not had upper respiratory tract symptoms or fever, and
there is no history of choking. The mother reports that the boy was seen
by the nephrologist 1 week ago, and because of worsening renal function,
he was begun on sodium bicarbonate.

Of the following, the electrolyte abnormality that BEST explains his current
symptoms is

A. hyperkalemia
B. hypermagnesemia
C. hypocalcemia
D. hyponatremia
E. hypophosphatemia
1. C
2. C
3. D
4. B
5. D
6. A
7. E
8. C
9. A
10. D
11. B
12. B
13. E
14. D
15. C
16. A
17. C
18. A
19. A
20. B
21. B
22. C
23. C
24. A
25. C
26. A
27. E
28. B
29. B
30. B
31. B
32. C
33. C
34. E
35. E
36. B
37. D
38. C
39. B
40. D
41. D
42. C
43. E
44. C
45. E
46. B
47. B
48. D
49. E
50. C