Pediatrics

The parents of a 14-day-old boy bring him to the emergency department in mid-winter due to a progressively worsening cough, nasal congestion, and a rectal temperature of 38.3°C (100.9°F) at home. He was born full-term following an uncomplicated pregnancy. His state newborn screening report recently returned flagged for undetectable T-cell receptor excision circles (TRECs), and an immunology consultation is scheduled for next week. In the emergency department, his temperature is 38.4°C (101.1°F), heart rate is 175/min, and respiratory rate is 72/min. Physical examination demonstrates nasal flaring, subcostal retractions, and bilateral diffuse wheezing and crackles. The physician notes scattered erythematous macules with 1- to 2-mm central yellow pustules on his trunk and proximal extremities, which the parents state have waxed and waned since his second day of life. A rapid multiplex viral polymerase chain reaction assay of nasopharyngeal secretions is positive for respiratory syncytial virus. The parents ask if he can receive his first dose of the oral rotavirus vaccine today since they missed their primary care appointment. Which of the following is the most appropriate next step in the management of this patient?

A 96-hour-old preterm male neonate (gestational age: 34 weeks, birth weight: 2100 g) is evaluated in the neonatal intensive care unit. He was delivered vaginally following spontaneous labor. Apgar scores were 7 and 9 at 1 and 5 minutes, respectively. Maternal history is notable for prolonged rupture of membranes (22 hours) and an intrapartum fever of $38.5^{\circ}\text{C}$ ($101.3^{\circ}\text{F}$).

At 2 hours of life, the neonate developed tachypnea, nasal flaring, and temperature instability. A complete sepsis workup was performed, and he was empirically started on intravenous ampicillin and gentamicin. He is currently breathing comfortably on room air. Vital signs are temperature $37.1^{\circ}\text{C}$ ($98.8^{\circ}\text{F}$), blood pressure 65/40 mm Hg, heart rate 140/min, and respiratory rate 42/min.

Skin examination reveals a new eruption of scattered, 2- to 3-mm erythematous macules and papules containing central yellow pustules over the chest and abdomen. The remainder of the examination is normal.

Laboratory results obtained at the time of admission are as follows:

The blood culture drawn at admission is now growing *Streptococcus agalactiae* (Group B *Streptococcus*). Antimicrobial susceptibility testing demonstrates that the isolate is susceptible to penicillin G, ampicillin, cefotaxime, and vancomycin. The CSF culture has shown no growth to date.

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

A $7$-month-old girl is brought to the emergency department due to progressive lethargy, poor feeding, and rapid breathing over the past $24$ hours. Her parents report that over the last few weeks, she has seemed "floppy" and has lost the ability to sit without support or roll over, both of which she had previously mastered.

Vital signs show a temperature of $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate of $160/\text{min}$, respiratory rate of $55/\text{min}$, and blood pressure of $85/50\text{ mm Hg}$. Physical examination reveals a lethargic infant with marked generalized hypotonia and profound head lag when pulled to sit. The lungs are clear to auscultation bilaterally without wheezing or crackles.

Laboratory results are as follows:
- $\text{Sodium}$: $138\text{ mEq/L}$
- $\text{Potassium}$: $4.5\text{ mEq/L}$
- $\text{Chloride}$: $98\text{ mEq/L}$
- $\text{Bicarbonate}$: $12\text{ mEq/L}$
- $\text{Blood urea nitrogen}$: $10\text{ mg/dL}$
- $\text{Creatinine}$: $0.3\text{ mg/dL}$
- $\text{Glucose}$: $78\text{ mg/dL}$
- $\text{Ammonia}$: $40\text{ \mu mol/L}$ (normal: $15-50\text{ \mu mol/L}$)
- $\text{Lactate}$: $9.2\text{ mmol/L}$ (normal: $0.5-2.2\text{ mmol/L}$)

Arterial blood gas analysis on room air reveals:
- $\text{pH}$: $7.25$
- $\text{PaCO}_2$: $30\text{ mm Hg}$
- $\text{PaO}_2$: $95\text{ mm Hg}$

Which of the following conclusions is most accurately supported by this patient's clinical and laboratory evaluation?

Below are four distinct clinical presentations of neonatal dermatologic conditions. Pair each patient vignette with its corresponding diagnostic finding or appropriate management strategy.

An unvaccinated 14-month-old female toddler is evaluated in the outpatient clinic in late autumn. She has a medical history of tetralogy of Fallot and 22q11.2 deletion syndrome (DiGeorge syndrome). Her parents report she has been experiencing intense, exhausting bouts of coughing for the past four days. These episodes are often followed by a high-pitched inspiratory sound and occasional vomiting. Two weeks prior, she had mild nasal congestion and a low-grade temperature that seemingly resolved. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate is $145/\text{min}$, and respiratory rate is $42/\text{min}$. On physical examination, the toddler appears fatigued. There are scattered, pinpoint, non-blanching red macules on her face and neck. Lung auscultation is clear between the coughing spasms.

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

A concerned mother brings her 11-month-old son to the outpatient clinic in late November. She reports that for the past three days, the infant has experienced severe nasal congestion and a progressively worsening cough. Today, she noticed his breathing appears faster than normal. Vital signs include a temperature of 38.1°C (100.6°F), heart rate of 145/min, respiratory rate of 52/min, and oxygen saturation of 94% on room air. Physical examination reveals an irritable but consolable infant with flaring of the nasal alae and mild intercostal retractions. Lung auscultation demonstrates bilateral expiratory wheezes and scattered coarse crackles. Which of the following interventions are appropriate for the initial management of this patient? (Select all that apply)

During routine morning rounds in the newborn nursery, a physician evaluates a female infant who developed a diffuse skin eruption at 16 hours of life. The infant was delivered via an uncomplicated vaginal birth at 39 weeks of gestation to a 26-year-old primigravida. Birth weight was $3.2\text{ kg}$ ($7.0\text{ lb}$). Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Vital signs are temperature $36.9^\circ\text{C}$ ($98.4^\circ\text{F}$), heart rate $142/\text{min}$, and respiratory rate $44/\text{min}$. The infant is alert, active, and feeding vigorously at the breast. Physical examination reveals numerous 2- to 3-mm superficial pustules on a non-erythematous base scattered across the chin, neck, and lower back. Several of the pustules have ruptured, leaving a collarette of fine scale and a central hyperpigmented macule. The remainder of the physical examination is unremarkable. Which of the following is the most appropriate next step in management?

A full-term male neonate (gestational age 40 weeks) is evaluated in the nursery at 48 hours of life due to progressive abdominal distension and two episodes of bilious emesis. A review of the nursing logs indicates that the infant has not yet passed meconium. Vital signs are within normal limits. Physical examination reveals a markedly distended abdomen that is soft and non-tender, with hypoactive bowel sounds. A digital rectal examination results in a sudden, explosive release of foul-smelling gas and stool. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological sequence for managing this patient's likely condition.

Match each neonatal clinical presentation with its most likely underlying diagnosis.

A 5-year-old boy arrives at the urgent care center with his mother because he has been struggling to breathe since early morning. His medical background is notable for atopic dermatitis and two prior episodes of respiratory distress requiring medical intervention in the past year. Over the preceding 48 hours, he developed severe nasal congestion and a dry, hacking cough. Today, his respiratory effort significantly worsened. His body temperature is 37.3°C (99.1°F), pulse is 125/min, and respirations are 36/min. Oxygen saturation is 92% on ambient air. Physical assessment demonstrates an anxious child in visible distress with prominent intercostal and subcostal retractions. Auscultation of the lungs reveals a prolonged expiratory phase accompanied by high-pitched, widespread expiratory wheezing. Which of the following is the most appropriate initial step in the management of this patient?

An unimmunized 4-year-old male is rushed to the emergency department by emergency medical services after an acute onset of high fever and severe dysphagia. Upon arrival, the patient is observed to be toxic-appearing, drooling, and sitting in a tripod position with a hyperextended neck. Audible inspiratory stridor is present. His temperature is 39.6°C (103.3°F), heart rate is 148/min, and respiratory rate is 38/min. Oxygen saturation is 93% on room air. The clinical presentation is highly suspicious for a life-threatening supraglottic infection. Arrange the following management steps in the most appropriate chronological sequence for this patient.

An 8-month-old infant girl is evaluated in the pediatric clinic during mid-winter for a three-day history of nasal congestion and a subjective low-grade fever. Today, her parents noticed that she developed a raspy cough and is breathing faster than usual. She has been feeding slightly less than normal but continues to have an adequate number of wet diapers. Her medical history is unremarkable, and she is up to date on all recommended immunizations. On physical examination, her temperature is $37.8^\circ\text{C}$ ($100.0^\circ\text{F}$), heart rate is $135/\text{min}$, respiratory rate is $56/\text{min}$, and oxygen saturation is $95\%$ on room air. The infant appears mildly fussy but is easily consolable. Auscultation of the chest reveals diffuse expiratory wheezing and scattered crackles bilaterally, accompanied by mild subcostal retractions. Which of the following is the most appropriate next step in the management of this patient?

An infant boy is evaluated in the neonatal intensive care unit for increased work of breathing. He was born 4 hours ago to a 30-year-old gravida 2, para 2 woman at 38 weeks gestation. Delivery was via elective repeat cesarean section prior to the onset of labor. The mother has a history of diet-controlled gestational diabetes. Her prenatal screening for group B *Streptococcus* was negative.

Upon evaluation, the infant appears tachypneic. Vital signs are temperature 36.9°C (98.4°F), heart rate 155/min, respiratory rate 82/min, and blood pressure 60/40 mm Hg. Oxygen saturation is 89% on room air. Physical examination reveals nasal flaring, subcostal retractions, and a clear chest to auscultation. The skin examination shows multiple 1- to 2-mm firm, pale yellow pustules surrounded by erythematous halos distributed across the trunk and proximal extremities.

Arterial blood gas on room air shows:

A chest radiograph demonstrates prominent perihilar vascular markings, hyperinflation, and a thin line of radiodensity in the right horizontal fissure.

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

Match each pediatric patient's clinical presentation to the most likely causative pathogen.

Emergency medical services transport a 2-year-old toddler to the pediatric department after the parents found the child unarousable in bed this morning. The parents note that the toddler had been suffering from a mild viral gastroenteritis over the last 48 hours, resulting in complete refusal of solid foods and minimal fluid intake. Medical history is unremarkable, and the child's weight and length have consistently tracked along the 50th percentile.

Upon arrival, the patient is deeply lethargic. Vital signs show a temperature of $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$), pulse of 160/min, and respiratory rate of 28/min. Physical assessment demonstrates a soft abdomen with the liver edge palpable 4 cm below the right costal margin. Neurological assessment reveals profound hypotonia without focal deficits.

Initial point-of-care testing and serum chemistry panel demonstrate:

A catheterized urine sample is obtained and is notably completely negative for acetoacetate and beta-hydroxybutyrate.

An impairment in which of the following metabolic pathways best explains this patient's clinical presentation?

A 12-hour-old male neonate is evaluated in the newborn nursery due to respiratory difficulty and a skin eruption. The infant was born at 38 weeks of gestation via uncomplicated vaginal delivery to a 19-year-old primigravida who recently immigrated and received no prenatal care.

Birth weight is 2100 g (4 lb 10 oz). APGAR scores were 7 and 8 at 1 and 5 minutes, respectively. Vital signs show a temperature of 37.3°C (99.1°F), heart rate of 165/min, and respiratory rate of 55/min.

Physical examination reveals a small-for-gestational-age infant with copious, clear nasal discharge. The abdomen is distended, and the liver edge is palpable 4 cm below the right costal margin along with a palpable spleen tip. Skin examination shows a widespread maculopapular rash with prominent desquamation involving the palms and soles.

Initial laboratory evaluation reveals the following:

Which of the following is the most appropriate next step in pharmacologic management for this infant?

During a school field trip, a 9-year-old girl with a history of atopy and reactive airway disease suddenly develops severe shortness of breath. By the time emergency medical services transport her to the hospital, she is lethargic and exhibiting head-bobbing with each breath. Vital signs on presentation include a heart rate of 158/min, respiratory rate of 46/min, and oxygen saturation of 83% on a non-rebreather mask. Auscultation reveals a "silent chest" with no discernible wheezing or air movement bilaterally. While the team prepares equipment for potential endotracheal intubation, which of the following pharmacological therapies must be initiated concurrently as part of the immediate resuscitation bundle? (Select all that apply)

During a routine morning nursery round, a physician evaluates a newborn male at 48 hours of life. The infant was delivered vaginally at 39 weeks gestation to a 22-year-old primigravida who received limited prenatal care. Maternal admission laboratory screening for HIV, hepatitis B, and syphilis were negative, but her Group B Streptococcus status was unknown. The newborn is breastfeeding vigorously and has had appropriate wet diapers and meconium passage. Vital signs show a temperature of 37.1 °C (98.8 °F), heart rate of 142/min, and respiratory rate of 42/min. Physical examination reveals an alert, well-appearing infant. There is a diffuse cutaneous eruption consisting of multiple 2- to 3-mm firm, yellowish pustules, each surrounded by a prominent erythematous macular base. The lesions are scattered across the chest, abdomen, and proximal thighs, but the palms and soles are completely clear. Mucous membranes are moist without lesions. Which of the following is the most appropriate next step in the management of this patient?

A 4-day-old full-term boy is brought to the neonatal intensive care unit with progressive lethargy, poor feeding, and vomiting. He was previously healthy and discharged home at 48 hours of life. Physical examination reveals a somnolent, tachypneic infant with no dysmorphic features. Sepsis evaluation is initiated. The clinical picture is highly suspicious for an inborn error of metabolism, specifically a urea cycle disorder.

Arrange the following diagnostic steps in the most appropriate sequential order to accurately identify the specific enzymatic defect in this patient.

A 7-year-old boy is brought to the emergency department by his parents due to a 24-hour history of high fever, severe headache, and recurrent vomiting. He is fully immunized. On physical examination, his temperature is 39.5°C (103.1°F), blood pressure is 105/65 mm Hg, heart rate is 118/min, and respiratory rate is 22/min. He appears acutely ill and lethargic. Marked nuchal rigidity is present on flexion of the neck. Neurologic examination reveals an inability to abduct the right eye. The remainder of the examination is unremarkable. Intravenous access is rapidly established. Arrange the following next steps in the most appropriate sequential order for managing this patient.