Pediatrics

Match each pediatric clinical presentation to its most likely underlying enzymatic deficiency.

A $5$-year-old boy is brought to the clinic by his parents due to rapid growth, facial acne, and the development of pubic hair over the past $6$ months. The parents also report that he has recently developed adult-type body odor. His height is at the $99$ th percentile for his age, whereas it was at the $50$ th percentile one year ago. His weight is at the $90$ th percentile. Vital signs are within normal limits. Physical examination reveals coarse, dark pubic hair (Tanner stage III) and facial acne. Genitourinary examination shows a stretched penile length of $6$ cm and bilaterally enlarged, symmetric testes with a volume of $8$ mL each. Neurologic examination is unremarkable.

Laboratory studies show:
Testosterone: $180$ ng/dL (Normal prepubertal: $<30$ ng/dL)
Basal luteinizing hormone (LH): $0.1$ mIU/mL (Normal prepubertal: $<0.3$ mIU/mL)
Thyroid-stimulating hormone (TSH): $1.8$ $\mu$ U/mL

A radiograph of the left hand and wrist reveals a bone age of $8$ years.

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

A $6$-month-old boy is brought to the clinic by his parents due to abnormal movements. Over the past $2$ weeks, he has had multiple episodes daily where he suddenly bends his head and trunk forward while stiffening his arms. These episodes occur in clusters, most often just after waking up from a nap. The parents are also highly concerned about his development because he has not yet begun to crawl or pull himself to a stand, though he rolls over in both directions and babbles. Vital signs are within normal limits. Neurologic examination shows a slightly hypotonic infant. Skin examination reveals three $2\text{-cm}$, elliptical, hypopigmented macules on his trunk that are accentuated under a Wood lamp. Laboratory studies show a thyroid-stimulating hormone (TSH) level of $2.5\ \mu\text{U/mL}$ and a free T4 of $1.2\ \text{ng/dL}$. An electroencephalogram demonstrates a high-voltage, chaotic, slow-wave background with multifocal spikes. Which of the following is the most appropriate next step in management?

An 18-month-old boy is brought to the pediatric pulmonology clinic due to persistent respiratory difficulties. Three months ago, he was hospitalized in the pediatric intensive care unit for a severe lower respiratory tract infection caused by *Adenovirus*, which required mechanical ventilation for seven days. Since discharge, he has exhibited continuous tachypnea, a daily wet cough, and audible wheezing. The patient has had no recent fever or rhinorrhea. Two separate five-day courses of oral prednisolone and regular administration of nebulized albuterol have provided no symptomatic relief. On physical examination, his temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate is $130/\text{min}$, respiratory rate is $52/\text{min}$, and oxygen saturation is $91\%$ on room air. Pulmonary auscultation reveals diffuse, bilateral expiratory wheezes and coarse crackles. A chest radiograph demonstrates bilateral hyperinflation without focal consolidation. Which of the following is the most appropriate next step in the evaluation or management of this patient?

A 16-year-old girl, who recently immigrated from a region with limited access to pediatric healthcare, is brought to the clinic for evaluation of primary amenorrhea and severe, progressive facial hair growth. Her mother notes that she has had a deep voice and experienced a rapid growth spurt during early childhood. Her blood pressure is 162/100 mm Hg, and her pulse is 78/min. Physical examination reveals severe nodulocystic acne, temporal hair thinning, and Tanner stage 5 pubic hair development, but Tanner stage 1 breast development. Pelvic examination demonstrates significant clitoromegaly and partial fusion of the labioscrotal folds. A transabdominal pelvic ultrasound confirms the presence of a uterus and bilateral ovaries. Laboratory testing shows a serum sodium of 146 mEq/L and a serum potassium of 2.8 mEq/L. Which of the following serum laboratory profiles (17-hydroxyprogesterone, 11-deoxycorticosterone, and plasma renin activity) is most likely present in this patient?

In early February, the parents of an 18-month-old girl bring her to the emergency department because she has been breathing rapidly and feeding poorly for the past 24 hours. The parents note that her symptoms began four days ago with a runny nose, mild nasal congestion, and a "tight" cough. She has a past medical history of atopic dermatitis managed with emollients. Her immunizations are up to date. Her temperature is 37.9°C (100.2°F), pulse is 158/min, respirations are 58/min, and oxygen saturation is 89% on room air. Physical examination reveals an irritable but consolable toddler with prominent nasal flaring and subcostal retractions. Lung auscultation demonstrates a prolonged expiratory phase, diffuse polyphonic wheezing, and bilateral coarse crackles. A chest radiograph displays bilateral hyperinflation, flattened hemidiaphragms, and a focal, wedge-shaped area of increased opacity in the right middle lobe. Which of the following is the most appropriate next step in management?

A 12-year-old boy is brought to the clinic for a 4-week history of right-sided knee pain and a progressive limp. The pain is characterized as a dull ache that is exacerbated by walking and participating in sports. He has no history of trauma, falls, or fever. His medical history is significant for growth hormone deficiency, for which he has been receiving somatropin injections for the past 6 months. His body mass index is at the 60th percentile for his age. His temperature is 37.1°C (98.8°F), blood pressure is 110/70 mm Hg, and pulse is 78/min. On physical examination, there is no swelling, erythema, or localized tenderness over the right knee, and ligamentous testing is stable. Range of motion of the right knee is full and painless. When the patient walks, he exhibits an antalgic gait with the right foot pointing outward. During examination of the hips, passive flexion of the right hip results in obligate external rotation of the thigh. Internal rotation of the right hip is limited compared to the left. Which of the following is the most appropriate next step in management?

A 15-month-old girl is brought to the clinic for a routine health maintenance visit. She lives with her parents and a 6-year-old brother who was diagnosed with acute lymphoblastic leukemia one month ago and is currently undergoing intensive induction chemotherapy. The parents express concern regarding the patient's development. They note that while she can say "mama" and "dada" specifically, she only has three other words in her vocabulary. Furthermore, she is unable to run or walk backward, though she walks independently without difficulty. She also scribbles spontaneously with crayons and drinks from a cup. Her immunizations are up to date through 6 months of age, but she missed her 12-month visit. The parents are reluctant to consent to any live-attenuated vaccines today, as they have read that these vaccines can shed and potentially cause severe infections in immunocompromised household members. Vital signs and physical examination are within normal limits. Which of the following is the most appropriate recommendation regarding this patient's management?

Evaluate the following clinical vignettes detailing neonates with suspected congenital infections. Match each clinical presentation to the most likely etiologic agent based on the distinctive physical and radiographic findings.

A full-term female infant is examined in the newborn nursery at $48\text{ hours}$ after birth due to the sudden appearance of a widespread skin eruption. She was born at $40\text{ weeks}$ of gestation via uncomplicated vaginal delivery to a $26\text{-year-old}$ primigravid mother. Maternal prenatal laboratory testing was unremarkable, and group B \textit{Streptococcus} screening was negative. Birth weight was $3,450\text{ g}$. Apgar scores were $7$ and $9$ at $1$ and $5\text{ minutes}$, respectively. The infant has been breastfeeding well every $2$ to $3\text{ hours}$ and has passed meconium and urine normally.

Vital signs are temperature $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), heart rate $135/\text{min}$, and respiratory rate $42/\text{min}$. Physical examination reveals an active, alert neonate. There is a disseminated rash characterized by multiple $1$ to $3\text{ mm}$ pale-yellow pustules surrounded by broad erythematous macules. The lesions are prominent on the trunk, face, and proximal extremities, but completely spare the palms and soles. The remainder of the physical examination, including neurologic reflexes, is within normal limits.

A complete blood count and microscopic evaluation of the pustular fluid are obtained. The results are as follows:

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

A 4-day-old term male neonate is brought to the emergency department due to repeated episodes of dark green vomiting over the past 4 hours. The infant has been exclusively breastfed and previously tolerated feeds without difficulty. Vital signs reveal a heart rate of 170/min, respiratory rate of 48/min, and blood pressure of 65/40 mm Hg. Physical examination shows a fussy neonate with a mildly distended abdomen and dry mucous membranes. Arrange the following steps in the most appropriate chronological order for the evaluation and management of this patient's condition.

Match each clinical presentation of a pediatric exanthem with its most likely causative viral pathogen.

A $4$-year-old boy is evaluated in the genetics clinic due to developmental delay and behavioral changes. His parents report that his early milestones were met on time, but over the past year, he has become increasingly hyperactive, aggressive, and his speech has regressed. Physical examination reveals a child with coarse facial features, a prominent forehead, and a widened nasal bridge. Abdominal examination demonstrates a liver edge palpable $4 \text{ cm}$ below the right costal margin and a palpable spleen. Musculoskeletal examination shows joint stiffness with decreased range of motion in the elbows, wrists, and knees. An ophthalmologic evaluation reveals clear corneas bilaterally without evidence of clouding. Which of the following is the most likely diagnosis?

A couple brings their 12-week-old infant son to the pediatric clinic because they noticed he breathes rapidly and sweats profusely whenever he nurses. The mother reports that feedings take nearly an hour, yet he often falls asleep exhausted before finishing. He has had no fever, cough, or nasal congestion. Review of his growth chart shows his weight has declined from the 30th percentile at birth to below the 5th percentile today. Vital signs show a temperature of 37.0°C (98.6°F), pulse of 168/min, and respiratory rate of 65/min. Pulse oximetry is 97% on room air. Physical examination reveals a thin infant with mild subcostal retractions and diffuse expiratory wheezes bilaterally. Cardiac auscultation demonstrates a hyperdynamic precordium and a prominent, harsh, grade 3/6 holosystolic murmur best heard at the left lower sternal border. The liver edge is palpable 4 cm below the right costal margin. Which of the following is the most appropriate initial pharmacological management for this patient?

A pediatric cardiology team is reviewing complex hemodynamic profiles and physical examination nuances of congenital heart defects. Carefully analyze the clinical presentations, physical examination findings, and diagnostic results provided. Which of the following best matches each specific clinical scenario with its most accurate underlying pathophysiology and diagnosis?

A $7$-month-old boy is brought to the emergency department due to progressive difficulty breathing and poor feeding over the past $24$ hours. One week ago, he had a mild upper respiratory tract infection that seemingly resolved. Currently, the infant is lethargic and sweating heavily during attempts to feed. Vital signs show a temperature of $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), heart rate of $178/\text{min}$, respiratory rate of $68/\text{min}$, and blood pressure of $65/40 \text{ mmHg}$. Oxygen saturation is $93\%$ on room air. Physical examination reveals marked intercostal retractions. Lung auscultation demonstrates diffuse wheezing and bilateral basilar crackles. Cardiac examination reveals tachycardia, a prominent $S_3$ gallop, and a grade $2/6$ holosystolic murmur at the apex. The liver edge is palpated $4 \text{ cm}$ below the right costal margin. Capillary refill time is $4$ seconds, and peripheral pulses are weak in all extremities. A chest radiograph demonstrates severe cardiomegaly with pulmonary venous congestion. Which of the following is the most appropriate next step in management?

During a mid-winter surge of respiratory illnesses, an $8$-month-old girl is evaluated in the pediatric emergency department for severe difficulty breathing. Her symptoms began three days ago with a runny nose, mild cough, and a maximum temperature of $38.0^\circ\text{C}$ ($100.4^\circ\text{F}$). Today, she became increasingly fussy, had two episodes of post-tussive emesis, and refused her last three bottle feeds. Her medical history is notable for delivery at $35$ weeks gestation and a family history of severe asthma in her father. Vital signs show a heart rate of $165$/min, respiratory rate of $68$/min, and oxygen saturation of $87\%$ on room air. Examination reveals an irritable infant with significant head bobbing, nasal flaring, and subcostal retractions. Lung auscultation is remarkable for a prolonged expiratory phase, diffuse polyphonic wheezing, and coarse bilateral crackles. A chest radiograph shows increased anterior-posterior diameter, flattened hemidiaphragms, and prominent perihilar markings but no focal opacities. Which of the following is the most appropriate next step in management?

Match each pediatric clinical presentation and diagnostic finding to the most likely congenital cardiovascular disorder.

A 4-year-old boy is brought to the emergency department due to a sudden onset of high fever, severe sore throat, and difficulty breathing that began 4 hours ago. He has not received any childhood immunizations due to parental preference. On examination, the patient appears toxic, anxious, and is sitting in a tripod position while drooling. He has marked inspiratory stridor and intercostal retractions. Oxygen saturation is 93% on room air.

Arrange the following steps in the most appropriate chronological order for the management of this patient's condition.

During a busy winter shift at an urgent care clinic, a 15-month-old girl is evaluated for three days of progressive rhinorrhea, mild cough, and a tactile fever. Over the last 12 hours, she has developed noisy breathing and decreased her solid food intake, though she continues to drink liquids from a sippy cup. She was born at 39 weeks gestation and has no significant past medical history. Her temperature is 37.7°C (99.9°F), pulse is 135/min, respirations are 48/min, and blood pressure is 90/55 mm Hg. Pulse oximetry shows 94% on room air. On examination, the patient is well-perfused and interactive. Lung auscultation reveals diffuse bilateral expiratory wheezes, scattered crackles, and mild subcostal retractions. A trial of a nebulized bronchodilator is administered in the clinic, but reassessment 30 minutes later shows no clinical change in her respiratory rate or auscultatory findings. Which of the following is the most appropriate next step in management?