Pediatrics

A 6-week-old boy is brought to the pediatrician by his mother due to a 7-day history of a worsening, repetitive cough. The mother describes the cough as occurring in rapid, short bursts, occasionally causing the infant's face to turn red, though without a distinct "whoop" sound or post-tussive emesis. The infant is exclusively breastfed and has been afebrile. He received his first hepatitis B vaccination at birth and is not yet due for his 2-month immunizations. Medical history is notable for bilateral mucopurulent eye discharge at 10 days of life, which resolved after a 7-day course of topical erythromycin ointment.

Vital signs are temperature 37.1°C (98.8°F), heart rate 145/min, respiratory rate 58/min, and oxygen saturation 95% on room air. Lung auscultation reveals bilateral scattered crackles and occasional expiratory wheezes without prominent intercostal retractions.

Laboratory testing shows a leukocyte count of $14,500/\text{mm}^3$ with $35\%$ neutrophils, $45\%$ lymphocytes, and $15\%$ eosinophils. A chest radiograph demonstrates bilateral symmetric interstitial infiltrates and hyperinflation.

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

A full-term female infant is delivered vaginally from a breech presentation. The mother has a positive family history of developmental dysplasia of the hip (DDH). The pediatrician is discussing the long-term evaluation and potential treatment plan for this condition with the parents. Assuming the patient will require the complete spectrum of standard medical intervention due to progressive or refractory disease, arrange the following steps in the chronological sequence they would be appropriately performed, starting from birth and progressing through late infancy.

In mid-January, a distressed father arrives at the emergency department with his $15$-month-old toddler. The child has been experiencing rapidly worsening respiratory distress over the past $12$ hours. The father reports that the illness began $4$ days ago with a runny nose, mild cough, and decreased appetite. The child's medical history is significant for atopic dermatitis, and his $6$-year-old sister recently missed school due to a severe asthma exacerbation.

Temperature is $38.1^\circ\text{C}$ ($100.6^\circ\text{F}$), pulse is $172$/min, and respirations are $68$/min. Pulse oximetry shows an oxygen saturation of $87\%$ on room air. The child appears lethargic but becomes irritable when handled. Physical examination reveals marked nasal flaring, grunting, and deep subcostal retractions. Auscultation of the chest demonstrates a prolonged expiratory phase with diffuse polyphonic wheezes, as well as fine inspiratory crackles at both lung bases. Cardiac examination reveals a regular tachycardia without murmurs. The liver edge is palpable $3$ cm below the right costal margin.

Capillary blood gas analysis on room air reveals the following:

Which of the following is the most appropriate initial management for this patient?

A 4-week-old boy is brought to the pediatric emergency department with a 12-hour history of high fever, progressive lethargy, and explosive, foul-smelling, bloody diarrhea. His parents report that his abdomen has become massively swollen over the past day. His neonatal history is notable for passage of meconium at 50 hours of life and chronic constipation requiring glycerin suppositories. Vital signs show a temperature of 39.1°C (102.4°F), heart rate of 185/min, respiratory rate of 60/min, and blood pressure of 65/35 mm Hg. Physical examination reveals a lethargic, mottled infant with a markedly distended and tympanic abdomen. Digital rectal examination results in a forceful expulsion of foul-smelling stool and gas. Arrange the following management steps in the most appropriate chronological sequence for this patient.

Evaluate the following clinical profiles of pediatric patients presenting with cytopenias. Assign each patient to the fundamental pathophysiologic mechanism or genetic defect that best explains their constellation of clinical and laboratory findings.

An 8-month-old infant is rapidly triaged in the emergency department following a syncopal event at home. According to the parents, the child was crying vigorously during a diaper change when he suddenly became deeply blue around the lips and face, followed by a brief loss of consciousness. The mother notes he has had similar, though milder, episodes of blueness when agitated over the past few weeks. The infant was born at a rural clinic and has not received subsequent medical care. On physical examination, the infant is awake but severely agitated. Vital signs demonstrate a heart rate of 180/min, respiratory rate of 55/min, and oxygen saturation of 74% on room air. Auscultation reveals a prominent right ventricular impulse and a harsh, crescendo-decrescendo systolic murmur at the left upper sternal border. Lung fields are clear to auscultation. Which of the following is the most appropriate initial step in the management of this patient?

An 11-week-old male infant is brought to the pediatric clinic by his parents because he has not had a bowel movement for the past six days. The parents report that his stools are typically small and hard, and his abdomen frequently appears bloated. They mention that after birth, he did not pass his first stool until he was almost two days old. The infant is exclusively formula-fed. Vital signs are within normal limits for his age. Physical examination demonstrates a distended but soft abdomen with normoactive bowel sounds. Digital rectal examination reveals a tight anal sphincter. Upon withdrawal of the examiner's finger, there is an explosive release of gas and foul-smelling stool. Which of the following is the most definitive test to confirm the diagnosis in this patient?

A 16-month-old girl is brought to the pediatric neurology clinic by her parents due to a frightening episode that occurred 2 days ago. While playing with her older brother, a toy was taken from her. She became enraged, cried vigorously, and then held her breath in expiration. She quickly turned blue around the lips and lost consciousness. During the 30 seconds she was unconscious, her parents witnessed two brief, symmetric jerking movements of her arms. She promptly regained consciousness and returned to her normal baseline within 2 minutes. The patient was born at term and has no significant past medical history. Her parents report she can walk independently, use a pincer grasp, and say "mama," "dada," and two other words. Vital signs are within normal limits. Physical examination demonstrates normal muscle tone, 5/5 strength, and 2+ deep tendon reflexes globally. Cardiovascular examination reveals a regular rate and rhythm with no murmurs. Which of the following is the most appropriate next step in the management of this patient?

Review the following hormonal and clinical profiles of pediatric and adolescent patients presenting with disorders of steroidogenesis. Correlate each specific laboratory and physical presentation with the most accurate underlying enzyme deficiency or clinical syndrome.

A 4-week-old boy is brought to the emergency department due to irritability and poor feeding that began earlier today. The mother notes he feels warm and is breathing faster than usual. On physical examination, the infant is awake but fussy. Capillary refill is 2 seconds, and peripheral pulses are strong. Vital signs are significant for a heart rate of 280/min, respiratory rate of 50/min, and blood pressure of 84/48 mm Hg. A 12-lead electrocardiogram demonstrates a regular, narrow QRS complex tachycardia with no discernible P waves. Intravenous access is successfully established. Arrange the following management steps in the most appropriate chronological sequence for this patient.

A worried father brings his $4$-year-old son to the pediatric clinic due to acute-onset refusal to walk over the past $24$ hours. The child was previously healthy except for a mild rhinovirus infection that resolved $10$ days ago. Current vital signs reveal a temperature of $38.9^{\circ}\text{C}$ ($102.0^{\circ}\text{F}$), pulse of $118/\text{min}$, and respirations of $22/\text{min}$. On physical examination, the child is irritable and resists any passive range of motion of the right hip, which is held in a flexed, abducted, and externally rotated position. Laboratory analysis demonstrates a leukocyte count of $14,500/\mu\text{L}$, an erythrocyte sedimentation rate (ESR) of $55 \text{ mm/h}$, and a C-reactive protein (CRP) level of $32 \text{ mg/L}$. Which of the following is the most appropriate next step in the management of this patient?

Match each pediatric clinical presentation to the most likely underlying congenital cardiovascular anomaly.

Match each classic clinical scenario to the most appropriate pediatric gastrointestinal diagnosis.

Match the following clinical presentations and diagnostic findings to their most likely underlying congenital heart defect.

A 14-month-old boy is brought to the clinic by his parents because of a swollen and tender right knee that developed yesterday. The patient recently started walking independently. The parents deny any major trauma but note that he frequently bumps into furniture. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), pulse is $110/\text{min}$, and respirations are $24/\text{min}$. Physical examination reveals a moderately swollen, warm right knee with a limited range of motion due to pain. There are also several large ecchymoses on his shins. Laboratory evaluation shows:

Hemoglobin: $11.8 \text{ g/dL}$
Platelet count: $310,000/\text{mm}^3$
Prothrombin time (PT): $12 \text{ seconds}$ (Normal: $11-15 \text{ seconds}$)
Activated partial thromboplastin time (aPTT): $72 \text{ seconds}$ (Normal: $25-40 \text{ seconds}$)

Which of the following is the most likely underlying cause of this patient's clinical presentation?

A 15-month-old girl is brought to the emergency department because of progressive unresponsiveness over the past 4 hours. She had a low-grade fever and poor oral intake for the last two days due to a presumed viral gastrointestinal illness. Today, she had two episodes of non-bilious vomiting and became extremely lethargic. Her parents also mention that prior to this illness, she had just begun walking independently and using 3 specific words; they have been anxious about whether her development is on track. On physical examination, she is obtunded and difficult to arouse. Her temperature is 37.2°C (99.0°F), heart rate is 165/min, blood pressure is 80/45 mm Hg, and respiratory rate is 44/min without wheezing or retractions. Abdominal examination reveals the liver edge palpable 3 cm below the right costal margin.

Laboratory studies show:

Intravenous dextrose is immediately administered, leading to rapid improvement in her mental status. In addition to supportive fluid therapy, which of the following is the most appropriate next step in the management or evaluation of this patient?

The neonatal intensive care unit team is called to assess a 36-hour-old full-term male who developed progressive abdominal distension and bilious emesis. He has not produced any meconium since birth. The infant was delivered vaginally at 39 weeks gestation to a 32-year-old mother whose pregnancy was complicated by poorly controlled gestational diabetes mellitus. His birth weight was 4.2 kg (9 lb 4 oz). Vital signs are within normal limits for age. Physical examination reveals a markedly distended and tympanitic abdomen without palpable masses, erythema, or tenderness. The anus is patent. An abdominal radiograph shows multiple dilated bowel loops with air-fluid levels and a paucity of distal gas. A water-soluble contrast enema is performed, revealing an abrupt transition in bowel caliber at the splenic flexure; the colon proximal to the splenic flexure is significantly dilated, while the descending colon and sigmoid colon are of uniformly small caliber. During the procedure, the infant passes a large meconium plug followed by copious amounts of stool and flatus, resulting in immediate relief of his abdominal distension. Which of the following is the most appropriate next step in the management of this patient?

A 14-month-old boy is brought to the pediatric clinic by his parents due to a persistent, scaly rash on his scalp and behind his ears that has been present for three months. He has also had chronic, bilateral, purulent ear discharge that has not improved despite three separate courses of oral amoxicillin. Recently, his parents noticed he is excessively thirsty and frequently soaks through his diapers, requiring multiple changes at night. On physical examination, the child is irritable but easily consolable. There is an erythematous, crusted, papular rash over the scalp, postauricular regions, and axillae. Abdominal palpation reveals mild hepatosplenomegaly. A skeletal survey is performed and demonstrates a 2.5-cm sharply marginated, "punched-out" lytic lesion in the right parietal bone without surrounding sclerosis. Which of the following is the most likely finding upon histologic or immunohistochemical evaluation of a biopsy from the bone lesion?

An $8$-year-old girl with a history of moderate persistent asthma is brought to the emergency department by emergency medical services due to severe respiratory distress. On arrival, she is tachypneic, diaphoretic, and sitting in a tripod position. Her respiratory rate is $48$/min, and oxygen saturation is $84\%$ on room air. Physical examination reveals severe suprasternal and intercostal retractions, with markedly diminished air entry and faint expiratory wheezing bilaterally.

Assuming the patient continues to clinically deteriorate and fails to improve at each stage of treatment, arrange the following interventions in the correct chronological sequence of therapeutic escalation for status asthmaticus.

A 24-month-old girl is brought to the pediatric neurology clinic by her parents due to a 2-week history of abnormal eye movements and severe unsteadiness. The parents report that she has sudden, erratic eye movements and frequent jerky movements of her trunk and extremities. She was previously walking independently but now refuses to walk. Past medical history is notable for a viral upper respiratory infection associated with diffuse wheezing last month. She was also seen in the urgent care clinic 48 hours ago for a fever; a urine culture from that visit just returned positive for Escherichia coli that is sensitive to ampicillin, cephalexin, and trimethoprim-sulfamethoxazole. Recent routine laboratory screening revealed a low total thyroxine (T4) level with a normal thyroid-stimulating hormone (TSH) level. During the interview, the parents express profound anxiety about her neurocognitive development, specifically noting that she is unable to ride a tricycle or speak in 3-word sentences. Physical examination reveals an alert toddler. Neurologic examination is significant for continuous, chaotic, multi-directional conjugate eye movements. She has generalized myoclonus and severe truncal ataxia. Palpation of the abdomen reveals a firm, non-tender mass in the right upper quadrant. Based on the clinical presentation and physical examination findings, what is the most appropriate next step in the management of this patient?