Pediatrics

A 6-year-old girl is brought to the pediatric oncology clinic by her father. The patient has acute lymphoblastic leukemia and is currently in the maintenance phase of chemotherapy, which includes daily oral mercaptopurine and weekly oral methotrexate. The father is concerned because the patient's 8-year-old brother was diagnosed with chickenpox yesterday after developing a widespread, pruritic, vesicular rash. The brother's symptoms began 48 hours ago. The patient has no history of clinical chickenpox. Review of her medical record indicates she received her first dose of the varicella vaccine at 12 months of age but missed the second dose. She is currently afebrile and asymptomatic, with an unremarkable physical examination. Which of the following is the most appropriate next step in management?

A 14-month-old boy is brought to the emergency department due to a 4-day history of high fever, severe respiratory distress, and a progressively worsening rash. His medical history is significant for a conotruncal cardiac anomaly (truncus arteriosus) that was surgically repaired at 1 week of age. His neonatal intensive care course was complicated by recurrent generalized tonic-clonic seizures that resolved after intravenous calcium gluconate infusions. He has had no recent sick contacts and does not attend daycare. Three weeks ago, he received his routine 12-month childhood immunizations at a mobile health clinic.

On physical examination, his temperature is 39.5°C (103.1°F), heart rate is 175/min, and respiratory rate is 55/min. Oxygen saturation is 86% on room air. The patient appears lethargic and toxic. Skin examination reveals a diffuse eruption of umbilicated vesicles on an erythematous base covering his face, trunk, and extremities. Several of the vesicles are hemorrhagic. Chest auscultation reveals diffuse bilateral crackles.

Laboratory evaluation shows:
Leukocyte count: 3,200/mm³
Neutrophils: 80%
Lymphocytes: 15%
Monocytes: 5%
Serum calcium: 8.2 mg/dL (normal: 8.5–10.5 mg/dL)

Chest radiograph demonstrates diffuse, bilateral nodular interstitial infiltrates.

Which of the following is the most appropriate next step in targeted pharmacotherapy for this patient?

A 14-day-old male infant is brought to the pediatrician by his mother due to a 3-day history of bilateral eye redness and discharge. The infant was born at 39 weeks gestation via an unassisted home birth to a 22-year-old mother who received no prenatal care. Postnatal care was limited, and the infant did not receive prophylactic eye drops at birth. The infant is breastfeeding well, produces 6 to 8 wet diapers daily, and has no fever or cough. Vital signs are within normal limits for his age. Physical examination shows bilateral eyelid edema, marked conjunctival injection, and moderate mucopurulent discharge. The remainder of the physical examination is unremarkable. Which of the following is the most appropriate next step in management?

Carefully review the following clinical presentations of neonates experiencing respiratory compromise. Match each patient's clinical scenario with the most accurate underlying pathophysiologic mechanism.

Match each pediatric patient presenting with suspected osteoarticular or disseminated infection to the most appropriate initial empiric antimicrobial regimen based on their specific clinical risk factors.

An $11$-month-old female infant presents to the pediatric outpatient clinic during the winter season accompanied by her parents. They report a $4$-day history of copious nasal discharge and a worsening, wet-sounding cough. Over the past $24$ hours, the parents noted an increased work of breathing. During the visit, the parents also mention they are worried because the infant is not yet walking independently, although she pulls herself to a stand and cruises along the furniture. She babbles and says "mama" and "dada" specifically. Her temperature is $37.7^\circ\text{C}$ ($99.9^\circ\text{F}$), heart rate is $142/\text{min}$, respiratory rate is $48/\text{min}$, and pulse oximetry is $96\%$ on room air. Physical examination reveals clear nasal secretions and mild subcostal retractions. Lung auscultation demonstrates diffuse bilateral expiratory wheezes and scattered coarse crackles. Cardiovascular examination is normal. Which of the following is the most appropriate next step in the management of this patient?

A 41-week gestation male infant is delivered via emergency cesarean section for placental abruption. He is limp and apneic at birth. Following initial warming, drying, and stimulation, his heart rate is 70/min. Positive pressure ventilation (PPV) is started via face mask. After 30 seconds of effective PPV with visible chest rise, his heart rate is 50/min. Assuming the infant's heart rate remains below 60/min despite each subsequent optimized intervention, arrange the following management steps in the correct chronological sequence according to the Neonatal Resuscitation Program (NRP) algorithm.

A 48-hour-old male neonate is evaluated in the newborn nursery during routine morning rounds. He was born at 39 weeks gestation via spontaneous vaginal delivery. His 22-year-old mother had prolonged rupture of membranes for 20 hours and developed a temperature of 38.2°C (100.8°F) shortly before delivery. She received two doses of intravenous ampicillin intrapartum. The infant's Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The infant's vital signs are temperature 37.1°C (98.8°F), heart rate 145/min, and respiratory rate 42/min. He is exclusively breastfeeding, latching well, and has had appropriate urine and meconium output. Physical examination reveals an alert, vigorous neonate. There is a prominent rash consisting of scattered 1- to 3-cm erythematous macules, many containing a central 1- to 2-mm pale-yellow pustule, distributed over the chest, abdomen, back, and proximal extremities. The palms and soles are completely spared. A complete blood count obtained at 24 hours of life shows a leukocyte count of 18,500/mm³ with 65% neutrophils and 10% bands. Which of the following is the most appropriate next step in the management of this patient?

A 4-year-old unvaccinated boy is brought to the emergency department with a 2-day history of high fever, severe headache, and progressive lethargy. On physical examination, temperature is 39.4°C (102.9°F), heart rate is 130/min, respiratory rate is 28/min, and blood pressure is 105/65 mm Hg. He is somnolent but arousable and has marked nuchal rigidity. Neurologic examination reveals a new-onset right-sided hemiparesis. Arrange the following management steps in the most appropriate chronological order for this patient.

Match each pediatric infectious disease exposure scenario with the single most appropriate post-exposure prophylaxis (PEP) or management step.

An 18-day-old female newborn is evaluated in the pediatric emergency room after her parents noticed she was unusually difficult to arouse this morning. Over the past 2 days, she has fed poorly and felt warm to the touch. The pregnancy was complicated by a lack of prenatal care until the third trimester, but the delivery was a spontaneous vaginal birth at term. Her temperature is $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), pulse is $175\text{/min}$, and respiratory rate is $50\text{/min}$. The infant appears lethargic and has a bulging, tense anterior fontanelle. During the physical examination, she experiences a focal clonic seizure involving the left upper extremity. Careful inspection of her skin reveals multiple scattered erythematous patches containing $1\text{-mm}$ yellow-white pustules over her trunk and proximal limbs. Lumbar puncture is performed, and cerebrospinal fluid (CSF) analysis shows the following:

Gram stain of the CSF reveals no organisms. Which of the following intravenous antimicrobial regimens is the most appropriate initial therapy for this patient?

A 15-month-old boy with a known, unrepaired congenital heart defect is brought to the pediatric cardiology clinic for a follow-up evaluation. The parents report that earlier today, the child became extremely fussy, began breathing rapidly, and developed a deep bluish discoloration around his lips during a crying spell. The mother immediately placed the toddler on his back and pushed his knees firmly against his chest, which rapidly resolved the cyanosis and calmed him down. This physical maneuver improved the patient's condition primarily by causing which of the following physiologic changes?

An 11-month-old girl is evaluated in the pediatric clinic for a follow-up appointment. The parents happily report that she is already strongly right-handed, consistently reaching for toys, feeding herself, and interacting with objects almost exclusively with her right hand. They note she often keeps her left hand clenched in a tight fist. She was born at 31 weeks gestation and required continuous positive airway pressure for two weeks due to respiratory distress. On physical examination, vital signs are within normal limits. Neurologic examination reveals increased muscle tone and brisk deep tendon reflexes in the left arm and left leg compared to the right. Which of the following is the most appropriate next step in management?

A 5-year-old girl is evaluated in the pediatric neurology clinic for progressive unsteadiness. Her parents report that she attained independent walking at 16 months of age, which was considered slightly delayed, but over the past year she has become increasingly clumsy and falls frequently. Additionally, they have noticed that she turns her entire head to follow moving objects rather than moving her eyes. Her medical history is significant for three hospital admissions due to severe bacterial pneumonia since age 2. Physical examination reveals a broad-based, unsteady gait and truncal titubation. Neurologic evaluation demonstrates markedly impaired smooth pursuit eye movements. Closer inspection of her face and eyes reveals prominent, blanching, tortuous vascular networks on the bulbar conjunctivae. Which of the following is the most appropriate management consideration for this patient?

A 13-year-old boy is brought to the pediatric neurology clinic by his parents due to progressive walking difficulties over the last 18 months. He frequently trips and recently had to stop playing on his school basketball team because he loses his balance easily. The parents note that his 10-year-old brother has also begun to display similar clumsiness. The patient's vital signs are within normal limits. Physical examination reveals high-arched feet and a noticeable lateral curvature of the thoracic spine. Neurological examination demonstrates a wide-based, unsteady gait. Deep tendon reflexes are absent at the knees and ankles, and there is markedly decreased vibratory and proprioceptive sensation in both lower extremities. Motor strength is mildly decreased in the distal lower extremities. Which of the following investigations is most appropriate to evaluate for the leading cause of mortality associated with this patient's underlying condition?

A $14$-month-old boy is brought to the emergency department by his parents due to persistent fever, worsening cough, and rapid breathing. Four days ago, he was seen at an urgent care clinic for a runny nose, low-grade fever, and diffuse wheezing. At that time, he was diagnosed with a viral upper respiratory tract infection and discharged with supportive care. Over the past $24$ hours, his temperature has spiked to $39.8^\circ\text{C}$ ($103.6^\circ\text{F}$). The patient has a history of mild atopic dermatitis. His immunizations are up to date, including the pneumococcal conjugate and Haemophilus influenzae type b vaccines. Vital signs show a heart rate of $165/\text{min}$, respiratory rate of $58/\text{min}$, and blood pressure of $90/55\text{ mm Hg}$. Oxygen saturation is $92\%$ on room air. On physical examination, the child appears acutely ill but is alert and interactive. Lung auscultation reveals diffuse expiratory wheezing and new focal crackles in the right lower lung field. A chest radiograph demonstrates a dense right lower lobe consolidation with a small, free-flowing right-sided pleural effusion. Which of the following is the most appropriate next step in pharmacologic management?

During a routine well-child visit, a pediatrician evaluates a 15-month-old girl due to parental concerns regarding her development. She is currently unable to stand with support and exhibits minimal vocalizations. Physical examination reveals several dysmorphic features, including a broad nasal bridge, low-set ears, and a single transverse palmar crease. The physician suspects an underlying genetic etiology. Arrange the following steps in the diagnostic evaluation and management of this patient in the most appropriate sequential order, progressing from initial clinical assessment to definitive management.

Match the following clinical and laboratory profiles of pediatric patients to the most likely underlying endocrine disorder.

Match the following clinical presentations of suspected adrenal enzyme deficiencies with their most likely underlying diagnosis. Evaluate both the mineralocorticoid status and the degree of virilization to determine the correct enzyme defect.

A 3-week-old boy is brought to the pediatric clinic by his parents due to 'seizures'. The parents report that over the past week, the infant has exhibited repetitive, rhythmic jerking movements of his arms and legs. These movements occur exclusively when he is asleep and cease immediately when his limbs are gently held or when he wakes up. The infant was born at 39 weeks gestation via an uncomplicated vaginal delivery. He is exclusively breastfed, feeds vigorously, and has normal urine and stool output. On physical examination, the infant is alert and has normal tone, reflexes, and pupil reactivity. His anterior fontanelle is flat and soft. Skin examination reveals multiple 1- to 3-mm yellow-white pustules on a broadly erythematous base scattered across his chest and back. Which of the following statements regarding this patient's condition and management are correct? (Select 2 that apply)