A 10-month-old boy is brought to clinic for evaluation of decreased activity.  The patient has been progressively tired over the past few weeks.  He normally is able to crawl and pull up to a stand, but lately he is so tired that he prefers to sit still.  The boy is primarily breastfed and eats some pureed fruits.  He has 6 or 7 wet diapers and 3 soft stools per day.  He has no known medical conditions or prior hospitalizations.  The patient lives with his parents and 3-year-old sister, none of whom have chronic medical conditions.  His parents are originally from Ghana and moved to the United States 4 years ago.  Temperature is 36.7 C (98 F) and pulse is 100/min.  Examination shows mild conjunctival pallor.  The lungs are clear to auscultation.  A 2/6 systolic murmur is auscultated over the precordium.  The abdomen is soft and nontender, and bowel sounds are present.  Laboratory results are as follows:

Which of the following is the most likely cause of this child’s anemia?

A 4-year-old girl is brought to the emergency department for evaluation of a rash.  This morning, the family noticed “lots of little spots on her arms and legs” that have now spread to her chest and trunk.  Her mother also noticed several bruises over the lower extremities and says, “She had a nosebleed this morning but it stopped after a few minutes.”  The patient and her family do not recall any preceding trauma.  She has no fever, vomiting, diarrhea, or decrease in appetite, but did have a “cough and runny nose a few weeks ago.”  The patient has mild, intermittent asthma for which she takes albuterol as needed.  Immunizations are up to date.  Temperature is 36.7 C (98 F), blood pressure is 100/60 mm Hg, pulse is 100/min, and respirations are 20/min.  Physical examination shows a well-appearing, smiling girl.  Scattered petechiae and ecchymoses are noted over the upper and lower extremities, chest, and trunk.  There are 3 small hematomas on the buccal mucosa, and there is dry, crusted blood in the left nostril.  Cardiac, abdominal, and lymphatic examinations are normal.  Laboratory results are as follows:

Which of the following is the most appropriate management for this patient?

A 5-year-old boy is brought to the emergency department with severe leg pain that started 6 hours earlier.  His mother says that their heating system broke last night so she “tried to keep him warm with lots of blankets.”  The patient was given ibuprofen and oxycodone at home without relief of pain.  He played outside with his brother yesterday but did not experience any trauma or injury.  He has not had fever, cough, vomiting, or rash.  Medical history includes mild persistent asthma and sickle cell disease, and he has been hospitalized once for a vaso-occlusive pain episode.  Temperature is 37.2 C (99 F), blood pressure is 100/62 mm Hg, pulse is 150/min, and respirations are 20/min.  Physical examination shows a young child lying in bed in significant discomfort, crying and holding his left leg.  Mucous membranes are moist and capillary refill is <2 seconds.  The lungs are clear to auscultation, and the abdomen is soft, nontender, and nondistended without organomegaly.  The left anterior calf is markedly tender to palpation but does not have erythema, warmth, or swelling.  A peripheral intravenous line is inserted, and a complete blood count is drawn.

Item 1 of 2

What is the best next step in management of this patient?

Item 2 of 2

The child is admitted to the hospital and experiences improvement of his leg pain overnight.  The next morning, however, he develops chest pain and difficulty breathing.  Temperature is 38.9 C (102 F), blood pressure is 94/62 mm Hg, pulse is 124/min, and respirations are 28/min.  The patient’s pulse oximetry shows 95% on room air.  Examination reveals diminished left-sided breath sounds with mild subcostal retractions.  Hemoglobin is stable from admission at 9.5 g/dL, and a blood culture is sent.  A chest x-ray is obtained.  Which of the following is the best next step in management of this patient?

A 5-year-old boy is brought to an urgent care center due to fatigue.  His mother says, “Normally, my son is running and jumping, but for the past week he has been resting on the couch and sleeping more than usual.  His eyes also look a bit yellow.”  He has had no fevers, vomiting, or difficulty breathing.  A week ago, the patient had a skin infection that resolved after treatment with oral antibiotics.  Review of medical records shows a normal hemoglobin screening at his 1-year well-child visit.  Family history is significant for a maternal uncle who had several similar episodes of tiredness and jaundice.  Physical examination reveals a tired-appearing boy lying on the examination table watching television.  His neck is supple without lymphadenopathy, and scleral icterus and mild jaundice are present.  His cardiac and abdominal examinations are normal.  Laboratory results are as follows:

Peripheral blood smear is notable for red blood cell fragments and intracellular deposits of denatured hemoglobin.  Which of the following is the next best step in the diagnostic workup for this patient?

A 4-year-old girl with sickle cell disease is brought to the emergency department with fatigue and loss of appetite.  Her parents first noticed her fatigue 3 days ago when she asked to go to sleep earlier than her bedtime.  Over the past 2 days, the patient has been drinking well but eating much less than normal.  Her father states, “She’s been so tired that she wouldn’t even get out of bed this morning.”  She had an episode of acute chest syndrome 2 years prior that required an exchange transfusion.  The patient takes folic acid and penicillin.  Immunizations are up to date, including the annual influenza vaccine.  Temperature is 36.7 C (98 F), blood pressure is 110/65 mm Hg, pulse is 120/min, and respirations are 25/min.  Oxygen saturation is 95% on room air.  Physical examination shows a pale and tired-appearing girl.  Conjunctival pallor is present.  Respiratory, abdominal, and neurologic examinations are within normal limits.  Laboratory results are as follows:

Which of the following is the most likely diagnosis of this patient?

An 8-week-old boy is brought to the emergency department by his parents due to fever that began a few hours ago.  The patient has had no cough or vomiting.  He was born at term and had jaundice after birth that resolved with phototherapy.  The patient has no known chronic medical conditions and takes no medications.  He has not yet received his 2-month vaccinations.  He is on a fortified soy-based formula.  Temperature is 38 C (100.4 F), pulse is 120/min, and respirations are 30/min.  Pulse oximetry is 99% on room air.  The patient is awake and alert.  He has clear nasal drainage, and the oropharynx is clear.  Cardiopulmonary examination is unremarkable.  The abdomen is soft with no organomegaly.  Skin examination shows no pallor or rashes.  Laboratory results are as follows:

Review of records shows that hemoglobin at birth was 18 g/dL.  Which of the following is the best response when discussing this laboratory change with the patient’s parents?

A newborn boy is evaluated on arrival in the nursery.  He was born 3 hours ago by spontaneous vaginal delivery at 40 weeks gestation after an uncomplicated pregnancy.  Apgar scores were 9 at 1 minute and 10 at 5 minutes after birth.  His mother has no significant medical history and does not take any medications.  Temperature is 36.7 C (98 F), pulse is 124/min, and respirations are 26/min.  He is awake, alert, and active with a strong cry.  His head is normocephalic and atraumatic with an open flat anterior fontanelle.  Pupils are equal and reactive to light and accommodation, and red reflexes are present bilaterally.  The nares are patent, there is no cleft lip or palate, and the pharynx is not erythematous.  Clavicles are intact without crepitus.  S1 and S2 are normal without murmurs, and lungs are clear to auscultation bilaterally.  The abdomen is soft, nontender, and nondistended with normal bowel sounds and no organomegaly.  Femoral pulses are normal and symmetrical.  All extremities move spontaneously and there is no edema.  There are no rashes, skin lesions, or jaundice, but the complexion appears ruddy with generalized erythema.  Blood samples obtained from the heel through simple prick method reveal a hematocrit of 70%.

Item 1 of 2

What is the most appropriate next step in management of this patient?

Item 2 of 2

Repeat testing revealed a hematocrit of 65%.  The patient is re-evaluated in the nursery and appears comfortable, with no tachycardia or respiratory distress.  He feeds slowly but has no emesis, and voids spontaneously after his first feed.  A decision is made to observe the child without intervention.  Approximately 12 hours later, he appears irritable and lethargic.  The infant has refused all subsequent feeds and has had decreased urine output.  Nursery staff observed an episode of apnea.  Temperature is 37.4 C (99.3 F), pulse is 170/min, and respirations are 60/min.  Physical examination shows a drowsy, hypotonic, poorly responsive newborn.  The fontanelle is open and flat.  Pupils are equal and reactive with normal red reflexes.  There is no rhinorrhea.  Oral mucosa is moist.  S1 and S2 are present without murmurs.  On pulmonary examination there are no wheezes or rales, but there are intercostal retractions.  The skin is erythematous and ruddy, and there is cyanosis of the fingertips.  There are no focal neurologic deficits.  Laboratory results from peripheral blood draw are as follows:

The patient is transferred to the neonatal intensive care unit, and treatment with intravenous fluids and glucose is initiated.  His symptoms fail to improve, and his hematocrit after several hours is 71%.  What is the most appropriate next step in management of this patient?

A 16-month-old full-term girl is brought to the office to establish well-child care.  The patient’s family recently moved to the area and they have no concerns about her development.  The patient weaned from breastfeeding at age 12 months, and her current diet mainly consists of whole cow’s milk.  She has no chronic medical conditions and takes no medications.  She was born to a 24-year-old primigravida Greek woman and a 30-year-old African American man.  The patient’s father has sickle cell trait and her first cousin has sickle cell anemia; maternal family history is noncontributory.  Physical examination reveals pallor of the conjunctivae but is otherwise unremarkable.  Laboratory results are as follows:

Hemoglobin electrophoresis reveals 40% HbS and 60% HbA.  Which of the following is the most likely cause of this patient’s anemia?

A 4-year-old boy is brought to the office with right leg pain.  The pain began about a week ago when the patient bumped his leg into a coffee table.  At the time, his parents were not concerned as he “cried for only a few minutes” and was able to walk normally afterward.  However, the pain has worsened over the past few days and the patient is now limping.  He also developed a persistent fever 4 days ago that is not improving despite ibuprofen and acetaminophen.  The patient has had no cough, vomiting, diarrhea, or rash.  Medical history is notable for sickle cell disease, and he has been hospitalized several times for vaso-occlusive pain crises.  He has no history of splenic sequestration or acute chest syndrome.  The patient takes no medications other than the antipyretics.  Immunizations are up to date.  Temperature is 39.4 C (103 F), blood pressure is 95/60 mm Hg, pulse is 158/min, and respirations are 30/min.  Physical examination shows warmth and swelling of the right distal thigh with decreased spontaneous movements, although the patient has full range of motion in his hips and knees.  The lungs are clear to auscultation with no increased work of breathing, and the abdomen is soft and nontender with no organomegaly.  Laboratory results are as follows:

Additional diagnostic testing is pending.  Which of the following is the most appropriate empiric antibiotic therapy for this patient?

A 3-day-old boy is in the nursery for routine evaluation.  He is breastfed exclusively and is passing adequate urine and stool.  He was born to a 22-year-old African American woman with an unremarkable prenatal course.  Prenatal laboratory studies showed a maternal blood type O positive.  The infant was delivered by repeat cesarean section at 39 weeks gestation, and his blood type is O positive.  A transcutaneous bilirubin level obtained at 24 hours of life was 3.4 mg/dL, which was considered low risk.  He has a healthy older sister who did not have jaundice in the newborn period.  Vital signs are normal.  Physical examination shows jaundice extending from the head to the thighs.  The lungs are clear to auscultation.  Abdominal examination reveals no tenderness, distension, or organomegaly.  Laboratory results from 72 hours of life are as follows:

Direct Coombs test is negative.  Serum bilirubin repeated 4 hours later is 20 mg/dL, and phototherapy treatment is initiated.  Which of the following is the most likely diagnosis?

A 7-year-old boy is brought to the office due to easy bruising and frequent epistaxis for 2 weeks.  Temperature is 36.7 C (98 F), blood pressure is 106/60 mm Hg, pulse is 94/min, and respirations are 18/min.  Examination shows pale lips with mucositis in the oropharynx.  The neck is supple.  The abdomen is soft, and pulses are 2+.  Laboratory results are as follows:

Findings from a bone marrow biopsy are shown in the image below:

Which of the following is the most likely diagnosis?

A 48-hour-old boy is evaluated in the newborn nursery on morning rounds.  The infant has been breastfeeding exclusively with good latch.  He passed meconium yesterday and has urinated several times, but the parents are concerned about his increasing yellow discoloration.  He was born at 38 weeks gestation via normal spontaneous vaginal delivery.  Review of prenatal records shows a maternal blood type of O+ and normal routine blood testing.  Physical examination shows an alert, nondysmorphic boy with a strong suck and intact Moro reflex.  He has icteric sclerae and appears jaundiced from head to feet.  The abdomen is soft, nontender, and nondistended.  The liver is palpable 1 cm below the right costal margin.  The examination is otherwise unremarkable.  The infant’s blood is drawn at 49 hours of life; laboratory results are as follows:

Which of the following is the most appropriate next step in management of this patient?

A 15-year-old boy comes to the office for a follow-up visit regarding acne.  He first developed acne a year ago and has tried over-the-counter acne washes with no improvement.  His first visit for acne was 3 months ago, at which time he was prescribed a topical retinoid and benzoyl peroxide for inflamed papules and pustules on his cheeks and forehead.  The patient says, “I’ve been using these 2 ointments every day.  Do you think I should keep using them?  Sometimes my face gets red and stings a little.  I don’t feel like my skin looks much better than before.”  He takes no other medications and always uses an oil-free, non-comedogenic sunscreen when outdoors.  He has no allergies.  Skin findings on examination are shown below.

Which of the following is the most appropriate next step in management of this patient?

A 7-month-old girl is brought to the office due to a rash.  The mother states, “The rash began 3 days ago on her buttocks and has spread to her genitalia.  I have been changing her diapers constantly and tried different brands of baby wipes, but the rash is getting worse.”  She reports that the child has been tugging at her diaper and has been “a little fussier than normal” but otherwise playful.  The patient has been drinking her usual 4 bottles of formula daily, and her sleep pattern has not changed.  A week ago, the child had a mild diarrheal illness that has since resolved.  She has had no fever, runny nose, or cough.  The patient was born full term without complications and has no chronic medical conditions.  Family history is significant for allergic rhinitis in her mother and asthma in her 4-year-old sister.  All vaccinations are up to date.  Temperature is 36.7 C (98.1 F), and all other vital signs are normal.  Physical examination reveals an active child in no distress.  The rash is shown in the image below.  A similar rash is present over the labia but not over the inguinal folds or thigh creases.

Which of the following is the best treatment for this patient?

A 17-year-old girl is brought to an urgent care center for sunburn.  She was jogging outside for an hour today and subsequently developed redness and pain on the exposed portion of her arms and face.  The patient says, “It wasn’t even that sunny today.  I’ve been outside for a lot longer than this and have never had a sunburn this bad.”  Her medical history includes acne vulgaris for which she was prescribed a topical and an oral medication, neither of which she can remember by name.  She does not take any other medications and has no allergies.  The patient is a long-distance runner for her high school track team.  She lives with her father, who has dyslipidemia.  Physical examination shows numerous comedones, papules, and pustules on her face and chest.  Confluent areas of erythema, warmth, and edema are present on the patient’s face and upper extremities.  Her left arm is shown in the image below.

Item 1 of 3

Which of the following medications most likely influenced the severity of this patient’s sunburn?

Item 2 of 3

Which of the following treatments is indicated for this patient’s condition?

Item 3 of 3

Over the next several months, the patient consistently uses a topical retinoid, a topical antibiotic, and an oral antibiotic.  She is also prescribed a daily oral contraceptive as adjunctive therapy for acne.  Six months later, the patient returns to the office for a follow-up appointment.  She says she is not sexually active, and review of systems is positive for occasional feelings of anxiety with school workload.  Current BMI is 19 kg/m².  Blood pressure is 90/60 mm Hg, and pulse is 68/min.  Examination shows oily skin on the forehead, nose, and cheeks.  Inflammatory and nodular acne is present on the face, back, and upper arms.  There is also scarring on the forehead.  The patient has no hirsutism or acanthosis nigricans.  Urine β-hCG is negative.  The patient desires the most effective treatment, and appropriate pharmacotherapy is discussed.  Which of the following should also be discussed prior to prescribing the new medication?

An 8-year-old girl is brought to the office by her mother due to hair loss on her scalp.  The mother first noticed a patch of hair loss a week ago, and the affected area is now slightly larger in diameter.  The area is flaking and very pruritic.  She also mentions, “My son had a similar rash on his arm but I didn’t want to use his cream on her without an evaluation.”  The patient has had no fever, and there is no oozing, warmth, or edema of the scalp.  She has no medical conditions and takes no medications.  Immunizations are up to date.  Physical examination shows a well-appearing girl who is scratching her scalp.  Examination of the area of hair loss is shown below.  Mildly tender posterior cervical lymphadenopathy is present.

Which of the following is the most appropriate treatment for this patient’s condition?

An 8-year-old boy is brought to the office due to a lower extremity skin rash for the past 3 days.  The rash began as tender papules that quickly progressed to form vesicles and flaccid bullae that rupture easily.  The patient has no mucosal lesions and has never had similar symptoms before.  He is up to date with recommended vaccinations and takes no medications.  Physical examination of the affected limb is shown below.

The skin overlying the rest of his body appears normal.  Which of the following is the most likely cause of this patient’s current presentation?

A 2-week-old girl is admitted to the hospital for dehydration and vomiting.  She was born via an uncomplicated vaginal delivery at home and did not undergo newborn screening.  Breastfeeding has been difficult due to the newborn’s lethargy and frequent vomiting.  The mother has no medical conditions, took no medications during pregnancy, and had normal prenatal laboratory results.  Family history is significant for a brother who died at age 1 month from severe dehydration several years ago.  The patient has a healthy 2-year-old sister.  Vital signs show hypotension and tachycardia.  Examination shows a sunken fontanelle and ambiguous genitalia.  The rest of the examination is unremarkable.  Abdominal x-ray and ultrasound, and upper gastrointestinal studies are normal.  Karyotype analysis is pending.  Serum chemistry results are as follows:

Item 1 of 3

A deficiency of which of the following is the most common cause of this patient’s presentation?

Item 2 of 3

Karyotype analysis shows 46,XX female.  Laboratory results would most likely show elevation of which of the following substrates?

Item 3 of 3

Which of the following is the best medication to administer in the treatment of this patient’s condition?