Pediatrics

A $16$-month-old boy is brought to the emergency department by his parents after they were unable to wake him up in the morning. For the past $48$ hours, the child has experienced a mild gastrointestinal illness characterized by vomiting and poor oral intake. Prior to this episode, he has been healthy and his developmental milestones are appropriate for his age. On physical examination, the child is lethargic and hypotonic, but has no rash, jaundice, or hepatosplenomegaly. Vital signs are within normal limits for his age, except for mild tachycardia. A point-of-care blood glucose measurement is $28$ mg/dL. Urinalysis is completely negative for ketones. Which of the following is the most appropriate next step in the management of this patient?

During a routine health maintenance visit, a $16$-year-old adolescent female and her mother express concern regarding the patient's worsening facial acne and irregular menstrual periods. Menarche occurred at age $12$, but over the past $2$ years, her menses have become increasingly unpredictable, occurring every $3$ to $5$ months. Recently, she has also noticed the development of coarse, dark hair on her upper lip and chin. The patient takes no medications and has no other medical conditions. Her blood pressure is $112/72\text{ mmHg}$, and her body mass index is $24\text{ kg/m}^2$. Physical examination reveals moderate cystic acne on the face and back, as well as significant hirsutism. A transabdominal pelvic ultrasound demonstrates bilaterally enlarged ovaries with multiple small peripheral cysts.

Laboratory studies obtained the previous week show the following:

Based on the clinical presentation and laboratory findings, which of the following is the most appropriate next step in the management of this patient?

A 4-year-old boy is brought to the pediatric neurology clinic by his parents due to increasing unsteadiness. The parents report that although he started walking independently at 14 months of age, he has become progressively clumsy over the past year and now falls frequently. He has also had four episodes of prolonged cough and wheezing over the last eight months, which were treated with a short-acting bronchodilator with minimal improvement. Vital signs are within normal limits. Physical examination reveals a wide-based, unsteady gait and dysmetria on finger-to-nose testing. Close inspection of the eyes shows prominent networks of fine, red, dilated blood vessels on the bulbar conjunctivae. The patient's immunization record indicates he is due for his routine 4-year-old vaccinations, which include the measles, mumps, and rubella (MMR) vaccine and the varicella vaccine. Based on the most likely underlying diagnosis, which of the following is the most appropriate next step in management?

A 15-year-old adolescent boy is brought to the emergency department via ambulance after collapsing during a high school basketball game. His friends report that he complained of a "racing heart" and severe shortness of breath right before feeling dizzy and sitting down on the court. He has a past medical history of a congenital heart defect that was surgically repaired during infancy, though he has not followed up with a cardiologist in several years. On arrival, he is agitated and diaphoretic. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $72/40 \text{ mm Hg}$, pulse is $215/\text{min}$, and respiratory rate is $28/\text{min}$. Pulse oximetry shows $93\%$ on room air. Physical examination reveals a right ventricular heave and a well-healed midline sternotomy scar. An electrocardiogram demonstrates a wide QRS complex tachycardia with a uniform morphology. Which of the following is the most appropriate next step in the management of this patient?

An 11-month-old boy is brought to the pediatric clinic by his parents due to a 4-day history of nasal congestion, low-grade fever, and noisy breathing. His parents note a new, "tight" cough that worsened last night. The patient has a history of mild atopic dermatitis. His father has moderate persistent asthma. The parents also express concern because the boy's 14-month-old cousin is already running, whereas this patient only pulls to stand and cruises along furniture but does not walk independently.

Temperature is 37.9°C (100.2°F), pulse is 138/min, respirations are 46/min, and pulse oximetry is 96% on room air. The patient appears comfortable and is drinking fluids well. Examination shows clear rhinorrhea. Tympanic membranes are slightly erythematous bilaterally, but there is no bulging and mobility is normal on pneumatic otoscopy. Lung auscultation reveals prolonged expiration, diffuse bilateral wheezes, and scattered coarse crackles, accompanied by mild intercostal retractions.

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

A 16-month-old girl is evaluated in the emergency department after her parents witnessed a 4-minute episode of generalized rhythmic jerking and loss of consciousness at home. Her rectal temperature in the emergency department is 39.2°C (102.6°F) and a rapid viral swab is positive for influenza A. She is currently fully awake, interactive, and drinking oral fluids. Her previous medical history is unremarkable, and she is up to date on immunizations. Which of the following statements regarding this patient's condition and management are correct? (Select all that apply)

A $5$-month-old boy is brought to the pediatric emergency department in January due to a $3$-day history of nasal congestion, clear rhinorrhea, and a mild cough. Over the past $24$ hours, his mother noticed that his breathing has become faster than usual and he has been feeding poorly. His mother has a history of seasonal allergies and asthma. His temperature is $37.8^\circ\text{C}$ ($100.0^\circ\text{F}$), pulse is $160/\text{min}$, respirations are $66/\text{min}$, and oxygen saturation is $93\%$ on room air. Physical examination reveals a fussy but consolable infant with moderate suprasternal and intercostal retractions, nasal flaring, and diffuse polyphonic wheezing with bilateral scattered crackles. Which of the following is the most appropriate next step in the management of this patient?

A $6$-year-old girl is evaluated in the pediatric endocrinology clinic for recent episodes of vaginal spotting and bilateral breast enlargement. Her parents report an unusually rapid growth spurt over the last $8$ months. Her medical history is notable for a recent nondisplaced right femur fracture after a minor trip and fall, which was attributed to a localized lytic bone lesion on radiographs.

Physical examination shows Tanner stage $3$ breast development and Tanner stage $1$ pubic hair. A large, flat, hyperpigmented skin macule with irregular, jagged margins is present on her left lateral trunk. Bone age radiography reveals a skeletal age of $10$ years.

Laboratory evaluation:

Pelvic ultrasound reveals a $3.5\text{-cm}$ unilateral ovarian cyst.

Which of the following pharmacologic mechanisms is most appropriate to halt the progression of this patient's pubertal development?

A $14$-year-old adolescent male is brought to the emergency department immediately following a basketball game due to severe, acute right knee pain. He reports that while forcefully contracting his quadriceps to jump for a rebound, he felt a loud "pop" in his knee and immediately collapsed to the floor. He has been unable to bear weight since the injury. The patient has a $6$-month history of localized pain over the right anterior proximal tibia that worsens with running, which his pediatrician previously diagnosed as a traction apophysitis. Vital signs are within normal limits. On physical examination, the right knee has a large, tense effusion. The patient is completely unable to perform a straight leg raise or actively extend the right knee against gravity. A distinct, palpable defect is noted just inferior to the patella, and the tibial tuberosity is exquisitely tender and appears proximally migrated. Radiographs demonstrate a displaced fracture fragment arising from the anterior proximal tibia. Which of the following is the most appropriate next step in the management of this patient?

During a busy evening shift at the pediatric emergency center, a 14-month-old male toddler is triaged for rapidly worsening breathing difficulties and profound lethargy. According to his caregivers, the child developed a persistent cough 72 hours ago and now completely refuses to crawl or pull to a stand. He was previously healthy, though he experienced a self-limited diarrheal illness approximately two weeks ago. Upon evaluation, his temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is 78/48 mmHg, heart rate is 185/min, and respiratory rate is 58/min. Pulse oximetry shows an oxygen saturation of 92% on ambient air. Physical assessment reveals a pale, mottled, and inconsolable child with significant subcostal retractions. Thoracic auscultation detects diffuse expiratory wheezing and bilateral basilar crackles. The cardiac rhythm is tachycardic with a distinct S3 gallop, but no discrete murmurs are appreciated. The inferior hepatic edge is palpable 4.5 cm below the right costal margin. A 12-lead electrocardiogram displays sinus tachycardia alongside low-voltage QRS complexes in the limb leads and diffuse T-wave flattening. Based on these findings, which of the following is the most appropriate next step in management?

A 4-year-old boy, who recently immigrated and has an unknown immunization history, is brought to the emergency department by his parents. Over the last 6 hours, he has developed a high fever, a muffled voice, and significant difficulty breathing. On physical examination, the child appears toxic and highly anxious. He is sitting upright, leaning forward with his neck extended, and drooling. His temperature is 39.5°C (103.1°F), heart rate is 150/min, respiratory rate is 42/min, and oxygen saturation is 93% on room air. Severe inspiratory stridor and marked intercostal retractions are noted visually. Arrange the following acute management steps in the most appropriate chronological sequence for this patient.

A 6-year-old girl is brought to the clinic by her parents due to breast development and the appearance of pubic hair over the past 6 months. Her parents also report that she has outgrown her clothes rapidly during this period. She has no significant past medical history and takes no medications. Her height is at the 98th percentile, and her weight is at the 90th percentile. Vital signs are within normal limits for her age. Physical examination reveals Tanner stage 3 breast development and Tanner stage 2 pubic hair. There is no axillary hair, acne, or clitoromegaly.

Initial workup reveals the following:
- Radiograph of the left wrist: Bone age of 9 years
- Basal luteinizing hormone (LH): 0.1 mIU/mL (normal prepubertal: < 0.3 mIU/mL)
- Follicle-stimulating hormone (FSH): 0.2 mIU/mL
- Estradiol: 45 pg/mL (elevated for age)

A gonadotropin-releasing hormone (GnRH) stimulation test is performed, and the peak LH level is measured at 0.2 mIU/mL.

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

A 4-year-old girl is evaluated in the emergency department for severe shortness of breath and wheezing. Her mother reports that the child developed a runny nose and a low-grade fever two days ago, which progressed to a persistent, tight cough and difficulty breathing this morning. The patient's medical history includes atopic dermatitis and allergic rhinitis, for which she uses emollients and as-needed oral antihistamines. Her immunizations are up-to-date. On arrival, her temperature is 37.3°C (99.1°F), pulse is 138/min, respirations are 44/min, and blood pressure is 95/60 mm Hg. Pulse oximetry shows 91% on room air. Physical examination reveals a distressed, tachypneic child sitting upright. There are prominent intercostal and subcostal retractions. Lung auscultation demonstrates a prolonged expiratory phase with diffuse, bilateral polyphonic wheezing. Which of the following is the most appropriate next step in management?

A 3-month-old girl is brought to the clinic by her parents because they are concerned about her feeding. The parents report that she tires easily, breaks into a sweat during feedings, and takes over 45 minutes to finish a 3-ounce bottle. Her weight has dropped from the 50th percentile at birth to the 5th percentile. Vital signs show a heart rate of 160/min and a respiratory rate of 65/min. Physical examination reveals a harsh, holosystolic murmur at the left lower sternal border with a palpable thrill. The liver edge is palpable 3 cm below the right costal margin, and bilateral fine crackles are heard on lung auscultation. Which of the following is the primary pathophysiological mechanism underlying this patient's current symptoms?

While playing unsupervised in a playroom, a 22-month-old toddler experiences a sudden onset of choking and spasmodic coughing. His caregiver reports that the intense coughing resolved after several minutes, but the child has since been breathing rapidly. He has been previously healthy with no recent fever or nasal congestion. Current vital signs include a temperature of 36.9°C (98.4°F), blood pressure of 96/58 mm Hg, pulse of 128/min, and a respiratory rate of 42/min. Pulse oximetry indicates 95% on room air. Physical examination demonstrates an alert child with mild subcostal retractions. Lung auscultation is notable for decreased air entry and a persistent, localized monophonic wheeze over the right hemithorax. A chest radiograph demonstrates hyperinflation of the right lung field with leftward mediastinal deviation that is accentuated on expiration. Which of the following is the most appropriate next step in management?

A 4-week-old female infant is brought to the clinic by her parents due to increased sleepiness and poor feeding over the past week. The parents report that she has to be awakened for feeds and has had only one hard, pellet-like bowel movement in the last four days. She was delivered at home at 39 weeks gestation to a 28-year-old primigravid woman and did not undergo state-mandated newborn screening. Vital signs include a heart rate of 92/min and a temperature of 36.0°C (96.8°F). Physical examination reveals a lethargic infant with mild scleral icterus, a large anterior fontanelle, a protuberant abdomen with an umbilical hernia, and hypotonia. Which of the following serum laboratory patterns is most likely to be found in this patient?

A 3-week-old boy is brought to the pediatric clinic by his mother because his 5-year-old sister developed a diffuse, pruritic, vesicular rash 2 days ago and was subsequently diagnosed with chickenpox. The mother reports having had a documented case of chickenpox during her own childhood. The patient was born prematurely at 27 weeks gestation and was recently discharged from the neonatal intensive care unit. Over the past 24 hours, the neonate has developed clear rhinorrhea and a mild cough. His temperature is 37.2°C (99.0°F), pulse is 150/min, respirations are 48/min, and oxygen saturation is 97% on room air. Physical examination shows a well-appearing neonate with scattered erythematous macules and papules on his chest. Auscultation of the lungs reveals mild, bilateral expiratory wheezes. Which of the following is the most appropriate next step in management for this patient?

A term male neonate (gestational age: 39 weeks, birth weight: 3200 g) is born at home to a 28-year-old multigravida mother who received no prenatal care. APGAR scores were 7 and 8 at 1 and 5 minutes, respectively. At 48 hours of life, the infant is brought to the emergency department due to extreme jaundice, profound lethargy, and failure to feed. Vital signs are: Temperature 36.8°C, Heart rate 110/min, Respiratory rate 35/min, and SpO2 98% on room air.

Initial laboratory results are as follows:

The infant is at immediate risk for severe bilirubin-induced neurologic dysfunction. Arrange the following clinical manifestations and pathophysiological events in the correct chronological sequence, representing the classic progression of this condition from the ongoing acute insult to the permanent neurologic sequelae of kernicterus.

Match each pediatric patient's clinical presentation with the statement that best describes the precise underlying pathophysiologic mechanism of their condition.

A 2-year-old boy is evaluated in the emergency department for a persistent fever of $39.6^\circ\text{C}$ ($103.3^\circ\text{F}$) that has lasted for 6 days despite regular use of acetaminophen. His mother notes he has been unusually irritable, has poor oral intake, and developed a mild cough today. On physical examination, the child has bilateral bulbar conjunctival injection without purulent discharge. His lips are noticeably erythematous, dry, and fissured. A $2.5\text{ cm}$ firm, tender lymph node is palpated in the right anterior cervical chain. A diffuse, polymorphous maculopapular rash is visible across his trunk and perineum. His hands and feet exhibit non-pitting edema and distinct erythema. Respiratory rate is 42/min, and oxygen saturation is 97% on room air. Lungs are clear to auscultation bilaterally. Cardiac examination reveals tachycardia but a regular rhythm with no murmurs. What is the most appropriate next step in the management of this patient's condition?