Pediatrics

A 13-month-old girl is diagnosed with roseola infantum (exanthema subitum), a common childhood illness primarily caused by Human Herpesvirus 6 (HHV-6). Arrange the classic clinical events of this viral infection in the chronological order they typically occur.

A 16-day-old male infant is brought to the emergency department after experiencing a generalized tonic-clonic seizure lasting approximately two minutes. The parents report that he has been increasingly irritable and feeding poorly for the past 24 hours. The patient was born at 38 weeks of gestation via an uncomplicated vaginal delivery. Maternal prenatal screening was unremarkable, including a negative rectovaginal culture for Group B *Streptococcus* at 36 weeks.

On physical examination, the infant is lethargic with a rectal temperature of $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), heart rate of $175/\text{min}$, and respiratory rate of $55/\text{min}$. He has a full, tense anterior fontanelle. A sparse, non-pruritic, erythematous papular eruption with central pustules is noted on the trunk.

A lumbar puncture is performed, and the cerebrospinal fluid (CSF) analysis reveals the following:

The patient is promptly started on empiric antimicrobial therapy. Forty-eight hours later, the laboratory reports that the CSF culture is growing a non-spore-forming, Gram-positive bacillus that exhibits tumbling motility at room temperature.

Based on these findings, which of the following is the most appropriate targeted pharmacotherapy for this patient?

An infant boy born at home at $38$ weeks gestation is evaluated in the pediatric clinic at $4$ weeks of life. His mother recently emigrated and received no prenatal care. The parents report the infant has had a persistent, thick, blood-tinged nasal discharge for the past week. Two days ago, a peeling rash developed on his hands and feet. On examination, the infant is irritable but afebrile. Copious purulent rhinorrhea is noted. There is a maculopapular, desquamating rash prominent on the bilateral palms and soles. The abdomen is distended, and the liver edge is palpable $3\text{ cm}$ below the right costal margin. The spleen is also palpable. Which of the following is the most appropriate targeted pharmacotherapy for this patient's underlying condition?

A 4-year-old boy is brought to the emergency department by his parents due to a widespread rash. He recently immigrated from a region with low immunization rates and has not received any childhood vaccinations. For the past four days, he has had a high fever, severe cough, runny nose, and red, watery eyes. Yesterday, a red, non-pruritic rash appeared on his face and has since spread down to his chest and back. His temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), pulse is $125/\text{min}$, and respirations are $24/\text{min}$. Physical examination reveals a generalized erythematous maculopapular exanthem. Examination of the oral cavity shows tiny white spots on a red base on the buccal mucosa opposite the premolars. The patient is placed in an airborne isolation room. Which of the following is the most appropriate pharmacotherapy for this patient's underlying condition?

Congenital infections (often referred to as TORCH infections) can present with distinct clinical syndromes in the neonatal period. Match each characteristic clinical presentation described below to its most likely causative pathogen.

A 16-month-old male toddler presents to the outpatient clinic with a 3-day history of fever, irritability, and left ear tugging. According to his mother, the child developed a low-grade fever and clear rhinorrhea approximately one week ago. Current vital signs include a temperature of 38.7°C (101.7°F), a heart rate of 124/min, and a respiratory rate of 26/min. Otoscopic evaluation of the left ear reveals a distinctly bulging, erythematous tympanic membrane that lacks mobility upon pneumatic testing. The right tympanic membrane is translucent with a normal light reflex. The patient's medical history is unremarkable, and he has received no antibiotics in the past year. He has no known drug allergies. Which of the following is the most appropriate initial pharmacotherapy for this patient?

A 2-hour-old male neonate is evaluated in the neonatal intensive care unit for worsening breathing difficulties. He was born at 31 weeks gestation via emergency cesarean delivery for non-reassuring fetal heart tones. Birth weight is $1,400$ g. APGAR scores were 3 at 1 minute and 6 at 5 minutes. Initial resuscitation included continuous positive airway pressure (CPAP), which is currently being maintained. Vital signs are temperature $36.5^\circ\text{C}$ ($97.7^\circ\text{F}$), heart rate 165/min, respiratory rate 75/min, and blood pressure 55/35 mm Hg. Pulse oximetry shows an oxygen saturation of 82% despite a CPAP of 8 cm H $_2$ O and an FiO $_2$ of 0.60.

Physical examination reveals profound intercostal and subcostal retractions, prominent nasal flaring, and audible expiratory grunting. Skin examination shows scattered 2- to 3-mm erythematous macules containing central yellow pustules over the trunk and proximal extremities. Auscultation reveals symmetrically decreased breath sounds bilaterally. A portable anteroposterior chest radiograph demonstrates a diffuse reticulogranular ground-glass appearance with prominent air bronchograms and low lung volumes.

An arterial blood gas is obtained:

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

An unvaccinated $7$-month-old boy is evaluated in the pediatric clinic for a relentless cough. According to his parents, the illness started approximately $14$ days ago with mild nasal congestion and a low-grade fever. Over the past week, his cough has dramatically worsened into intense, rapid spasms. During these coughing fits, the infant becomes cyanotic around the mouth and frequently vomits his formula afterward. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate is $142/\text{min}$, respiratory rate is $38/\text{min}$, and oxygen saturation is $97\%$ on room air. On physical examination, the child appears well-nourished but has bilateral subconjunctival hemorrhages. Auscultation of the lungs reveals clear breath sounds bilaterally with no wheezing or crackles between coughing episodes. A complete blood count reveals a leukocyte count of $24,000/\text{mm}^3$ with $75\%$ lymphocytes. Which of the following is the most appropriate next step in management?

Neonatal respiratory distress can result from a variety of pulmonary and extrapulmonary conditions. Differentiating these conditions often relies heavily on the initial radiographic evaluation. Match each neonatal respiratory condition below to its most characteristic initial chest radiograph presentation.

A 16-month-old male toddler is carried into the acute care clinic by his father because he has been completely unwilling to stand or bear weight on his legs since yesterday evening. The father states that the child was previously healthy and recently started attending a new daycare center. Over the past 24 hours, the toddler has become increasingly irritable, refuses to eat, and feels very warm to the touch. Vital signs show a heart rate of 138/min, respiratory rate of 26/min, and a temperature of 39.3°C (102.7°F). On physical examination, the child cries inconsolably when the physician attempts passive range of motion of the right lower extremity. The right hip is held in a rigidly flexed, abducted, and externally rotated position. Laboratory testing reveals a leukocyte count of 17,200/mm³ and an erythrocyte sedimentation rate of 72 mm/hr. Which of the following represents the most appropriate immediate management for this patient?

Emergency medical services bring an unvaccinated 4-year-old male to the resuscitation bay due to sudden-onset respiratory distress and high fever. The parents report he has been drooling excessively and refusing to swallow. On observation, the child is extremely anxious, leaning forward with his neck hyperextended and resting his hands on his knees. Loud inspiratory stridor is heard. Arrange the following acute management steps in the most appropriate chronological sequence for this patient.

A preterm neonate, born at 27 weeks gestation, is currently on day 18 of life in the neonatal intensive care unit. The nursing staff reports a sudden clinical deterioration characterized by temperature instability (hypothermia to 35.6°C [96.1°F]), recurrent prolonged apneic spells, and marked hypotonia. On assessment, the infant is poorly responsive with a heart rate of 195/min, respiratory rate of 20/min with irregular shallow breaths, and a mean arterial pressure of 22 mm Hg. Capillary refill is delayed at 5 seconds. Late-onset neonatal sepsis is suspected. Arrange the following steps in the most appropriate chronological sequence for managing this critically ill patient.

A 5-year-old girl is admitted to the pediatric ward with severe right thigh pain, fever, and an inability to bear weight. Magnetic resonance imaging confirms acute hematogenous osteomyelitis of the right femur. She is empirically started on a regimen of intravenous vancomycin and ceftriaxone. On hospital day 3, her clinical condition has significantly improved, and she has been afebrile for 24 hours. Blood cultures and a deep tissue aspirate obtained on admission both grow *Staphylococcus aureus*. Antimicrobial susceptibility testing reveals the isolate is resistant to penicillin, but susceptible to oxacillin, cefazolin, and clindamycin. The patient has no known drug allergies. Which of the following is the most appropriate antimicrobial regimen for this patient at this time?

A $21$-day-old male infant born at $34$ weeks gestation is evaluated in the pediatric clinic for a spreading rash in the diaper area that has worsened over the past $4$ days. He was discharged from the neonatal intensive care unit one week ago after a $14$-day stay for prematurity and suspected early-onset neonatal sepsis, for which he received a $7$-day course of intravenous ampicillin and gentamicin. Currently, he is breastfeeding well and gaining weight appropriately. Vital signs include a temperature of $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate of $140$/min, and respiratory rate of $38$/min. Physical examination of the perineal region reveals sharply demarcated, beefy-red plaques that prominently involve the inguinal creases. Several pinpoint erythematous papules and pustules are scattered on the lower abdomen and upper thighs, distinct from the primary confluent rash. Which of the following is the most appropriate next step in management for this patient's skin condition?

Match each classic pediatric clinical presentation with its most likely causative pathogen.

A 14-day-old male neonate is brought to the pediatric clinic by his parents due to a facial rash that appeared 2 days ago. The infant was born at 39 weeks gestation via uncomplicated vaginal delivery to a 25-year-old primigravida. His birth weight was 3.4 kg (7 lb 8 oz), and Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The parents report that the infant is breastfeeding vigorously every 2 to 3 hours and produces 6 to 8 wet diapers daily. Maternal history is significant for recurrent genital herpes; she was treated with daily acyclovir starting at 36 weeks gestation and had no active lesions at the time of delivery. Maternal group B Streptococcus screening was negative.

The infant appears comfortable and well-hydrated. Current vital signs are as follows:

Physical examination reveals multiple $1$- to $2\text{-mm}$ erythematous papules and pustules predominantly distributed across the cheeks, chin, and forehead. There are no vesicles, comedones, or areas of honey-colored crusting. The lesions lack a broad surrounding area of erythema. The remainder of the physical examination, including a detailed neurologic assessment, is normal.

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

A term male neonate is born at 39 weeks gestation to a 28-year-old mother who received no prenatal care. Her blood type is subsequently found to be O-negative. The infant develops visible scleral and cutaneous jaundice within the first 12 hours of life. Arrange the following diagnostic and therapeutic interventions in the correct escalating sequence for managing suspected severe isoimmune hemolytic disease of the newborn, from the initial evaluation to the most advanced intervention for severe, refractory cases.

Match the following neonatal clinical presentations and investigative findings to their most likely underlying diagnosis.

Shortly after an uncomplicated, scheduled cesarean delivery at 38 weeks of gestation for breech presentation, an infant develops rapid, shallow breathing. The mother received standard prenatal care and had intact membranes until the time of the operation. At 2 hours of life, the neonate's respiratory rate is 74/min, and oxygen saturation is 96% on room air. Physical examination reveals mild nasal flaring, subcostal retractions, and clear breath sounds bilaterally. Cardiac auscultation demonstrates a regular rate and rhythm without murmurs. Additionally, the physician notes several scattered blanching erythematous macules containing central yellow-white papules on the infant's chest and abdomen. A chest radiograph demonstrates hyperinflation, prominent perihilar vascular markings, and a small amount of fluid in the right minor fissure. Which of the following is the most appropriate management for this patient?

A $6$-day-old male neonate is evaluated in the emergency department due to poor feeding, lethargy, and increased work of breathing over the past $12$ hours. He was born at $39$ weeks gestation via an uncomplicated vaginal delivery and was discharged home at $48$ hours of life. Temperature is $36.4^\circ\text{C}$ ($97.5^\circ\text{F}$), heart rate is $185$/min, and respiratory rate is $68$/min. Oxygen saturation is $94\%$ on room air in the right hand; a reliable plethysmographic waveform cannot be obtained in either foot. Physical examination reveals an ashen, mottled appearance with a prolonged capillary refill time of $5$ seconds. Marked subcostal retractions and grunting are present. The right brachial pulse is full and bounding, while bilateral femoral pulses are barely palpable. Blood pressure measured in the right arm is $84/45$ mmHg, and in the left leg is $46/24$ mmHg. Arterial blood gas analysis reveals a pH of $7.12$, pCO $_2$ of $32$ mmHg, and pO $_2$ of $75$ mmHg, with a calculated bicarbonate of $10$ mEq/L. Which of the following is the most appropriate initial step in management?