Pediatrics

A 15-month-old boy is brought to the clinic for a routine well-child visit. He has not received any immunizations since his 6-month well-child visit due to missed appointments. Five months ago, he was hospitalized for 5 days and successfully treated with high-dose intravenous immunoglobulin (IVIG) and aspirin for Kawasaki disease. He currently takes no medications and has no other medical conditions. His parents express concern because he is not yet running or speaking in two-word phrases. He currently walks independently, drinks from a cup, and says three specific words other than "mama" and "dada". Vital signs are within normal limits, and physical examination shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?

A 3-day-old male infant is brought to the emergency department by his parents due to poor feeding, lethargy, and a bluish discoloration of his lips that started this morning. The infant was born at 39 weeks gestation via uncomplicated vaginal delivery and was discharged home at 48 hours of life. On arrival, the infant appears mottled and lethargic. Vital signs show a temperature of 36.5°C (97.7°F), heart rate of 185/min, respiratory rate of 72/min, and blood pressure of 55/35 mm Hg in the right arm and 53/34 mm Hg in the left leg. Oxygen saturation is 72% on room air. Administration of 100% oxygen via non-rebreather mask for 10 minutes raises the oxygen saturation to 74%. Physical examination reveals central cyanosis and prominent subcostal retractions. Cardiac auscultation demonstrates a single, loud second heart sound (S2) and a grade 2/6 systolic ejection murmur at the left upper sternal border. The liver edge is palpated 3 cm below the right costal margin. Femoral pulses are equal but diminished bilaterally. Capillary refill time is 4 seconds. Which of the following is the most appropriate next step in management?

A 12-year-old girl is brought to the clinic by her parents due to fatigue, poor school performance, and constipation over the past 6 months. Her parents also note that she frequently complains of feeling cold, even in warm weather. Growth chart review shows her height has dropped from the 50th percentile two years ago to the 15th percentile currently, while her weight has increased from the 50th to the 75th percentile. Physical examination reveals dry skin, a diffusely enlarged and non-tender thyroid gland (goiter), and delayed relaxation of the deep tendon reflexes. Laboratory studies show a low serum free T4 level and a markedly elevated TSH level. Which of the following is the most likely underlying mechanism of this patient's condition?

A 13-year-old boy is brought to the clinic by his mother due to a 3-week history of right knee pain and a progressive limp. He describes the pain as a dull, constant ache that worsens with physical activity. He denies any recent trauma, fever, chills, or weight loss. His medical history is unremarkable. He is at the 95th percentile for weight and 50th percentile for height. Vital signs are within normal limits. On physical examination, the right knee has no effusion, erythema, warmth, or tenderness to palpation. Ligamentous and meniscal testing of the knee is unremarkable. When asked to walk, the patient demonstrates an antalgic gait. During range of motion testing of the right lower extremity, passive flexion of the right hip results in obligatory external rotation of the thigh. Which of the following is the most appropriate next step in management?

A 10-month-old boy is brought to the emergency department by his parents after experiencing a sudden episode of generalized shaking that lasted for approximately 1 minute. During the episode, the patient's eyes rolled back, and he was unresponsive to his parents' voices. By the time they arrived at the emergency department, the shaking had stopped and he had fully regained consciousness. Over the past two days, the infant has had clear rhinorrhea, a mild cough, and a tactile fever. His temperature is 39.2°C (102.6°F), heart rate is 145/min, blood pressure is 90/60 mmHg, and respiratory rate is 42/min. On physical examination, the infant is awake, alert, and playfully reaching for the physician's stethoscope. Auscultation of the lungs reveals diffuse bilateral expiratory wheezing. Neurologic examination shows normal muscle tone, symmetric reflexes, and no focal deficits. The parents note that he recently started pulling himself up to a stand and says "dada" and "mama". Which of the following is the most appropriate next step in the management of this patient?

Match the following pediatric endocrine conditions to their most characteristic clinical or laboratory presentation.

A 12-year-old boy is brought to the pediatric endocrinology clinic by his parents due to poor growth and increasing fatigue over the past 12 months. He used to be energetic but now frequently falls asleep in class. He also complains of feeling cold, even during the summer, and reports new-onset frequent morning headaches. Over the past year, his height has plateaued, falling from the 50th percentile to below the 10th percentile. Physical examination reveals a pale, prepubertal boy with dry skin and delayed relaxation phase of deep tendon reflexes. Visual field testing by confrontation reveals diminished peripheral vision bilaterally. Which of the following serum laboratory patterns is most likely present in this patient?

A $2$-hour-old term male neonate is evaluated in the neonatal intensive care unit for profound cyanosis that developed shortly after birth. His mother had an uncomplicated pregnancy and vaginal delivery. On initial evaluation, his oxygen saturation was $60\%$ on room air and failed to improve significantly during a hyperoxia test. An echocardiogram revealed D-transposition of the great arteries with an intact ventricular septum. An intravenous prostaglandin E1 infusion was promptly initiated. One hour later, the neonate becomes apneic, requiring endotracheal intubation and mechanical ventilation. Despite $100\%$ fraction of inspired oxygen ($FiO_2$) on the ventilator, his oxygen saturation remains at $58\%$. An arterial blood gas shows pH $7.15$, $PaCO_2$ $40$ mmHg, $PaO_2$ $25$ mmHg, and $HCO_3^-$ $14$ mEq/L. The patient is tachycardic and hypotensive. A repeat bedside echocardiogram demonstrates a widely patent ductus arteriosus and a severely restrictive patent foramen ovale bowing right-to-left. Which of the following is the next best step in management?

Match each of the following pediatric congenital heart defects with its classic clinical or auscultatory finding.

A 5-year-old unimmunized boy is brought to the emergency department by his parents due to sudden onset of high fever, difficulty swallowing, and drooling. He is sitting upright, leaning forward with his neck extended, and appears toxic. He has marked inspiratory stridor and severe suprasternal retractions. Arrange the following steps in the most appropriate sequential order for the acute management of this patient.

A 6-month-old boy is brought to the pediatric clinic by his parents due to strange jerking movements that began two weeks ago. The parents report that he suddenly flexes his neck, trunk, and arms for 1 to 2 seconds. These movements occur in clusters of up to 20 episodes, typically just after he wakes from a nap. Previously, the infant had begun to roll over and smile, but he has not done either since these episodes started. He was born at 39 weeks' gestation without complications. Temperature is 37.0°C (98.6°F), heart rate is 120/min, and blood pressure is 85/50 mm Hg. Physical examination reveals three 1.5-cm elliptical, hypopigmented macules on his trunk that become more prominent under a Wood's lamp. The remainder of the examination shows decreased muscle tone. An electroencephalogram (EEG) demonstrates a high-amplitude, chaotic background with asynchronous, multifocal spikes and slow waves. Which of the following is the most appropriate next step in the management of this patient?

A 7-month-old boy is brought to the clinic by his parents due to "strange movements" that began two weeks ago. The parents report that the child has episodes where he suddenly bends his head and body forward while extending his arms stiffly. These episodes last for a few seconds, occur in clusters of 10 to 15, and typically happen just after he wakes up from a nap. Previously, the infant was able to sit with support and babble, but recently he has stopped vocalizing and seems less engaged with his surroundings. Vital signs are within normal limits for age. Physical examination reveals an infant who does not visually track objects well. Skin examination under a Wood lamp reveals three 2-cm elliptical hypopigmented macules on his trunk. An electroencephalogram (EEG) demonstrates a chaotic, high-voltage, asynchronous background with intermixed multifocal spikes and slow waves. Which of the following is the most appropriate initial pharmacotherapy for this patient's underlying condition?

A 10-month-old boy is brought to the emergency department by his parents following an episode of profound cyanosis. The parents report that he was crying inconsolably when he suddenly developed blue discoloration around his lips and began breathing very rapidly. His mother states she instinctively brought his knees to his chest, which seemed to gradually improve his color over several minutes. The patient has a history of a heart murmur, but the family recently immigrated and his medical records are unavailable. He is currently resting quietly. Vital signs are temperature 37.1°C (98.8°F), heart rate 130/min, respiratory rate 28/min, and blood pressure 85/50 mm Hg. Oxygen saturation is 94% on room air. Cardiac auscultation reveals a normal S1, a single S2, and a grade 3/6 harsh systolic ejection murmur heard best at the left upper sternal border. If a similar cyanotic episode recurs while the patient is in the emergency department, which of the following is the most appropriate next step in management?

An 8-year-old boy is brought to the clinic by his parents due to a 1-month history of right knee pain and a worsening right-sided limp. He has no history of trauma, fever, or recent illnesses. His parents note that he has been growing at a slower rate than his peers, falling from the 50th percentile to the 5th percentile for height over the past two years. His current weight is at the 30th percentile. The parents also report that he has been more fatigued lately and has developed constipation. Vital signs are within normal limits. On physical examination, the right knee has no effusion, erythema, or tenderness; range of motion is full and painless. Evaluation of the right hip reveals limited internal rotation. When the right hip is passively flexed, the thigh obligatorily rotates externally. Radiographs of the right hip show widening of the proximal femoral physis and posterior displacement of the femoral head relative to the femoral neck. Which of the following is the most appropriate next step in the management of this patient?

Match the following clinical vignettes of neonatal cyanotic heart disease with the most likely underlying congenital cardiac defect.

A 4-year-old boy presents to the emergency department with acute-onset limping and an inability to bear weight on his right lower extremity. His parents report that he developed a high fever earlier today. He was previously healthy and has no recent history of trauma. Temperature is 39.1°C (102.4°F), blood pressure is 100/65 mm Hg, and pulse is 125/min. On examination, the patient is distressed. The right hip is held in a position of flexion, abduction, and external rotation. Passive range of motion of the right hip elicits severe pain. There is no overlying erythema or swelling. Arrange the following steps in the most appropriate chronological order for the evaluation and management of this patient's condition.

A 7-month-old infant is brought to the pediatric clinic by his parents who report that he has been having recurrent episodes of sudden, brief, symmetric forward flexion of the neck and trunk with arm extension. These episodes occur in clusters, particularly when he is waking from sleep. Physical examination reveals three hypopigmented macules on his trunk that fluoresce under a Wood lamp. Which of the following additional clinical or diagnostic findings are most likely to be associated with this patient's underlying condition? (Select all that apply)

A 9-year-old boy is brought to the pediatrician by his parents for evaluation of fatigue, constipation, and poor growth. The parents report that he has been feeling cold even in warm weather and has not outgrown any of his clothes over the past year. Review of his growth chart shows a decline in height from the 50th percentile to the 10th percentile. Physical examination reveals dry skin and delayed relaxation of the ankle reflexes. Laboratory evaluation shows a free T4 level of $0.5 \text{ ng/dL}$ (normal: $0.9-1.7 \text{ ng/dL}$) and a thyroid-stimulating hormone (TSH) level of $2.1 \text{ }\mu\text{U/mL}$ (normal: $0.5-4.5 \text{ }\mu\text{U/mL}$). Which of the following is the most likely diagnosis?

A 3-year-old boy is brought to the emergency department by his parents due to a rapidly worsening sore throat, high fever, and difficulty breathing that began 4 hours ago. The parents recently immigrated and state the child has not received any childhood immunizations. On examination, the patient appears toxic, anxious, and is sitting leaning forward with his neck extended and chin thrust out. He is drooling and has a muffled voice. Temperature is 39.8°C (103.6°F), heart rate is 155/min, and respiratory rate is 42/min. Oxygen saturation is 91% on room air. Marked inspiratory stridor and suprasternal retractions are present.

Arrange the following interventions in the most appropriate chronological sequence for the management of this patient.

A 5-year-old boy is brought to the emergency department by his parents due to a sudden onset of right hip pain and a complete refusal to bear weight on his right leg since this morning. His temperature is 38.9°C (102.0°F). On physical examination, he appears uncomfortable and holds his right hip in a flexed, abducted, and externally rotated position. Any attempt at passive range of motion of the right hip elicits severe crying and guarding. The clinical suspicion for septic arthritis is high. Arrange the following diagnostic and therapeutic steps in the most appropriate sequential order for the management of this patient.