Pediatrics

A $4$-day-old female newborn is brought to the outpatient clinic for a routine follow-up examination. She was delivered at term ($38$ weeks gestation) via an uncomplicated vaginal birth and is exclusively breastfed. Her mother reports that the infant struggles to latch onto the breast and often falls asleep after only a few minutes of nursing. Over the past $24$ hours, the infant has produced only $2$ wet diapers and continues to pass dark, sticky stools. On physical examination, the infant appears lethargic with dry oral mucous membranes and a slightly sunken anterior fontanelle. Scleral icterus is present, and jaundice extends to her upper chest. Her current weight is $2.85$ kg, which represents an $11\%$ decrease from her birth weight of $3.20$ kg.

Laboratory studies reveal the following:

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

Emergency medical services arrive at the pediatric resuscitation bay with a $7$-year-old girl who has become progressively unresponsive over the past $12$ hours. Her caregivers describe a $3$-week prodrome of early morning cephalgia and forceful emesis. Just prior to EMS arrival, she experienced a self-resolving, $2$-minute episode of generalized body stiffening and jerking.

Initial vital signs demonstrate a temperature of $37.2^\circ\text{C}$, a heart rate of $54\text{/min}$, a blood pressure of $148/96\text{ mmHg}$, and respirations of $10\text{/min}$ with apneic pauses.

Neurologic evaluation reveals a comatose patient who does not open her eyes or vocalize, but withdraws her left arm and leg in response to nailbed pressure. The right pupil measures $7\text{ mm}$ and is fixed, whereas the left pupil measures $3\text{ mm}$ and reacts briskly to light. Deep tendon reflexes are $3+$ on the left side, and a left-sided extensor plantar response is noted.

Arrange the following interventions in the most appropriate chronological sequence for the acute management of this patient's condition.

A $7$-year-old boy is brought to the clinic by his parents due to a $2$-month history of bedwetting. He had been completely toilet trained during the day and night since the age of $4$. His parents note that he now frequently asks to use the bathroom during school and constantly craves cold water. The patient has no history of head trauma or recent illnesses. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $95/60 \text{ mm Hg}$, and pulse is $98\text{/min}$. Physical examination is unremarkable, and his growth is tracking along the $50^{\text{th}}$ percentile for both height and weight.

Initial laboratory results are as follows:

A formal water deprivation test is performed. After $6$ hours, his urine osmolality remains low at $120 \text{ mOsm/kg H}_2\text{O}$, and his serum sodium rises to $152 \text{ mEq/L}$. Subcutaneous desmopressin is then administered. Two hours later, his urine osmolality increases to $580 \text{ mOsm/kg H}_2\text{O}$.

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

An 18-month-old boy is evaluated in the pediatric clinic for progressive bowing of his legs and a waddling gait. The parents note that he began walking independently at 14 months of age, but his leg bowing has worsened since then. He was exclusively breastfed until 6 months, after which appropriate solid foods were introduced. He receives daily multivitamin drops containing 400 IU of cholecalciferol. His height is at the 3rd percentile, and his weight is at the 25th percentile. Physical examination reveals frontal bossing, widening of the wrists, and pronounced genu varum. Laboratory studies show:

Which of the following is the most likely underlying pathophysiology of this patient's condition?

An 18-month-old girl is brought to the pediatric neurology clinic by her parents due to ongoing concerns about her development and a recent "shaking episode." Yesterday, the child experienced a 1-minute generalized tonic-clonic seizure that resolved spontaneously. The parents report that over the past 4 months, the patient has completely stopped speaking the few words she knew (e.g., "mama," "dada") and no longer attempts to feed herself. Instead, she spends most of her day repetitively wringing and clasping her hands. Her past medical history is notable for normal development until 12 months of age. Additionally, she has had clear rhinorrhea for the past 2 days. On examination, the patient's temperature is 37.1°C (98.8°F), heart rate is 108/min, and respiratory rate is 22/min. The lungs are clear to auscultation bilaterally. Neurologic examination reveals a wide-based, unsteady gait and an absent pincer grasp. Review of her pediatric growth chart demonstrates that her head circumference has dropped from the 50th percentile at age 12 months to the 5th percentile currently, whereas her length and weight have remained on the 50th percentile curves. Which of the following is the most appropriate next step in the management of this patient?

A 4-month-old boy is brought to the emergency department due to poor feeding and a weak cry for the past 3 days. The parents report that he has been progressively less active and has not had a bowel movement in 5 days. He was previously healthy and exclusively breastfed, though the parents recently began dipping his pacifier in honey to soothe him. He was born at full term and his newborn screen was normal. His temperature is $37.1^\circ C$ ($98.8^\circ F$), heart rate is $140/\text{min}$, and respiratory rate is $35/\text{min}$. On physical examination, the infant appears listless. He has bilateral ptosis, sluggish pupillary responses to light, and an absent gag reflex. There is marked head lag and generalized hypotonia. The abdomen is soft and non-distended with hypoactive bowel sounds. Laboratory testing shows a thyroid-stimulating hormone (TSH) level of $2.4 \mu\text{U/mL}$ (normal: $0.5-5.0 \mu\text{U/mL}$). Which of the following is the most appropriate next step in management for this patient?

A 7-year-old boy is brought to the pediatric orthopedics clinic by his parents due to a persistent limp favoring his left leg. The parents report that the limping began approximately 5 weeks ago and is particularly noticeable after he plays outside. He occasionally complains of a dull ache in his left anterior thigh, but he denies any knee or back pain. There is no history of recent trauma, falls, or upper respiratory tract infections. His temperature is 37.0°C (98.6°F), blood pressure is 98/62 mm Hg, and pulse is 84/min. On physical examination, the patient has an antalgic gait. The left hip demonstrates restricted internal rotation and limited abduction compared to the right hip. The circumference of the left thigh is 2 cm smaller than that of the right thigh. Laboratory evaluation reveals a leukocyte count of 6,800/mm³, an erythrocyte sedimentation rate of 9 mm/hr, and a C-reactive protein level of 0.3 mg/dL. Anteroposterior and frog-leg lateral radiographs of the pelvis show completely normal bony architecture, symmetric joint spaces, and no epiphyseal flattening. Which of the following is the most appropriate next step in the diagnostic workup or management of this patient?

During a routine health maintenance visit, a physician evaluates a 2-year-old girl due to parental concerns regarding significant behavioral changes. The parents state that she achieved all early developmental milestones appropriately, including sitting unassisted at 6 months and saying single words at 12 months. However, over the past 8 months, she has lost her vocabulary and no longer makes purposeful reaching movements with her hands. Instead, she continuously claps and wrings her hands together. The parents also report intermittent episodes where she breathes very rapidly and forcefully, occasionally leading to mild wheezing, followed by periods of breath-holding. Physical examination reveals an alert child who avoids eye contact. Her head circumference has dropped from the 50th percentile at age 6 months to the 5th percentile currently. She exhibits no signs of acute distress and remains afebrile. Based on the most likely underlying condition, which of the following is the most appropriate next step in management or evaluation?

A 1-month-old boy is evaluated in the pediatric emergency department due to a 4-day history of progressively forceful vomiting. The parents report that he eagerly feeds but regurgitates the entire volume immediately afterward. The vomitus consists of undigested milk and does not appear green. The infant has not had a bowel movement in two days and is producing fewer wet diapers. Vital signs show a heart rate of $170/\text{min}$, respiratory rate of $35/\text{min}$, and blood pressure of $75/45 \text{ mm Hg}$. Physical examination reveals a lethargic infant with a sunken anterior fontanelle, dry mucous membranes, and delayed capillary refill. Palpation of the abdomen reveals a $2\text{-cm}$, firm, mobile mass in the right epigastrium. Laboratory studies reveal a pH of $7.52$, serum sodium of $132 \text{ mEq/L}$, potassium of $2.9 \text{ mEq/L}$, and chloride of $88 \text{ mEq/L}$. What is the most appropriate next step in the management of this patient?

A primary care physician is reviewing developmental screening profiles for several pediatric patients. Match each patient's clinical presentation with the most appropriate interpretation and next step in management.

Parents bring their 15-month-old son to a new pediatric clinic for a health maintenance examination. The family recently relocated from another state, which caused them to miss the child's standard 12-month evaluation. A review of his electronic medical record confirms he received all age-appropriate immunizations through his 6-month well-child visit. At 13 months of age, he experienced a generalized tonic-clonic convulsion lasting 2 minutes during an episode of high fever associated with roseola infantum. His 4-year-old sister also had a history of seizures with high fevers as an infant. Currently, the boy is healthy and takes no daily medications. Developmentally, he walks independently, stoops to pick up objects without losing his balance, points to items he wants, and uses three specific words consistently in addition to "mama" and "dada". Vital signs and physical examination are unremarkable. The physician is preparing to order catch-up vaccines, including those for measles, mumps, rubella (MMR), varicella, and seasonal influenza.

Which of the following is the most appropriate approach to this patient's preventive care today?

A 12-month-old girl is brought to the pediatric clinic for a routine health maintenance evaluation. She was born at 39 weeks of gestation via spontaneous vaginal delivery to a mother with poorly controlled HIV infection, and the patient was subsequently diagnosed with perinatal HIV at age 2 months. The patient is currently asymptomatic and her mother reports strict adherence to the prescribed antiretroviral therapy. Vital signs are temperature $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate 110/min, respiratory rate 24/min, and blood pressure 85/55 mm Hg. Physical examination reveals an active, well-nourished child with normal growth parameters and no lymphadenopathy or hepatosplenomegaly. Laboratory studies from two weeks ago demonstrate a CD4+ T-lymphocyte count of $1,250/\text{mm}^3$ and a CD4 percentage of $28\%$. Her immunizations are up to date and have consisted entirely of age-appropriate inactivated vaccines. The mother asks whether her daughter can receive the measles, mumps, and rubella (MMR) and varicella vaccines today. Which of the following is the most appropriate action?

A female neonate born at 26 weeks gestation weighing 850 g (1 lb 14 oz) is evaluated on day 15 of life in the neonatal intensive care unit. The infant has been gradually advancing on enteral feeds with fortified human milk. Over the past 8 hours, the infant has developed temperature instability, lethargy, and one episode of bilious emesis. Nursing staff notes significantly increased gastric residual volumes. Vital signs are temperature 35.4°C (95.7°F), heart rate 175/min, respiratory rate 65/min, and blood pressure 42/22 mm Hg. Physical examination reveals a distended, tense, and erythematous abdomen with absent bowel sounds.

Laboratory studies show the following:

An anteroposterior abdominal radiograph demonstrates dilated bowel loops, intramural air in the right lower quadrant, and branching radiolucencies over the hepatic shadow. There is no free air under the diaphragm. Enteral feeds are immediately discontinued, and an orogastric tube is placed for decompression.

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

A $48$-hour-old term female newborn is evaluated in the nursery for a new skin eruption. The infant was born at $39$ weeks gestation via uncomplicated vaginal delivery to a $25$-year-old primigravid mother. The mother's prenatal screening laboratory tests were unremarkable, although she reports having had a mild, self-resolving upper respiratory tract illness $2$ weeks prior to delivery. The infant is exclusively breastfeeding every $2$ to $3$ hours and is producing normal wet and soiled diapers. Vital signs include a temperature of $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), heart rate of $135\text{/min}$, and respiratory rate of $42\text{/min}$. On physical examination, the newborn appears comfortable and alert. Skin examination reveals a widely distributed rash consisting of $2$- to $3$-mm blanching, erythematous macules, many of which contain central, firm, $1$-mm yellow-white pustules. The lesions are prominent on the trunk and face, but the palms and soles are completely spared. There is no associated lymphadenopathy, hepatosplenomegaly, or neurologic deficit. A complete blood count demonstrates a leukocyte count of $16,500/\text{mm}^3$ with an eosinophil fraction of $8\%$. Which of the following is the most appropriate next step in the management of this patient?

An 8-week-old infant is brought to the emergency department due to rapid breathing and poor feeding. The parents report that over the past two weeks, the infant has become profoundly pale, sweaty, and excessively fussy during breastfeeding, often terminating feeds after only a few minutes due to apparent exhaustion. The infant's weight has fallen from the 50th percentile at birth to the 5th percentile currently. Vital signs include a temperature of 37.1°C, a heart rate of 170/min, a respiratory rate of 68/min, and a blood pressure of 82/48 mm Hg measured equally in all extremities. Oxygen saturation is 96% on room air. Capillary blood gas analysis reveals:

Physical examination reveals bilateral intercostal retractions, nasal flaring, and diffuse expiratory wheezes. Cardiac auscultation demonstrates a grade 3/6 holosystolic murmur best heard at the apex with radiation to the left axilla. The liver edge is palpated 4 cm below the right costal margin. An electrocardiogram displays deep, narrow Q waves and ST-segment elevations in leads I, aVL, V5, and V6.

Which of the following best explains this patient's clinical findings?

A parent brings their 24-month-old son to the pediatric clinic due to concerns about his language development. The parent states that the child says only five words, including 'mama' and 'dada', and primarily uses pointing to request items. He does not put words together to form phrases. The child is able to walk up and down stairs while holding onto the railing, kick a ball, and stack a tower of six blocks. He frequently brings books to his parent to read and engages in pretend play with a toy kitchen. He responds to his name consistently and follows simple commands. A routine screening for autism spectrum disorder performed today shows a low-risk profile. Physical examination shows no abnormalities. Which of the following is the most appropriate next step in management?

A pediatric nursing team is reviewing normal developmental markers to improve their triage and anticipatory guidance protocols. Match each cluster of observed developmental behaviors with the most appropriate age of the child.

A 24-month-old boy is brought to the clinic for a routine well-child visit. His parents have no specific concerns. On developmental assessment, the boy is able to run well, kick a ball, and walk up and down the stairs placing both feet on each step. He can build a tower of six cubes, turn the pages of a book one at a time, and remove his shoes. He has a vocabulary of approximately 50 words, uses two-word phrases, and his speech is understood by strangers about half of the time. When in the waiting room, he plays with his own toys alongside other children but does not directly interact with them. Physical examination is unremarkable. The pediatrician provides anticipatory guidance to the parents regarding the developmental milestones expected over the upcoming year. Which of the following skills is this patient most likely to acquire by his next annual visit at 36 months of age?

A $48$-hour-old male neonate is evaluated in the well-baby nursery due to a newly developed, rapidly spreading rash. The infant was born at $39$ weeks gestation via spontaneous vaginal delivery to a $28$-year-old mother. The mother's prenatal history is notable for a primary genital herpes simplex virus infection at $14$ weeks gestation, which was treated with oral valacyclovir; she had no prodromal symptoms or active lesions at the time of delivery. The infant's vital signs are temperature $37.3^\circ\text{C}$ ($99.1^\circ\text{F}$), heart rate $142$/min, and respiratory rate $42$/min. He is breastfeeding vigorously and has normal tone. Skin examination reveals numerous $2$-mm to $3$-mm firm, pale-yellow pustules, each situated on a wide, blotchy erythematous base. The lesions are scattered over the thorax, abdomen, and proximal thighs, while the palms, soles, and oral mucosa remain entirely clear. A smear of the pustular contents is performed to rule out infectious etiologies, showing no microorganisms. Based on the most likely diagnosis, which of the following best describes the underlying pathophysiology of this infant's cutaneous findings?

A full-term male newborn is evaluated in the hospital nursery on his third day of life. The parents express concern about a sudden skin eruption that appeared on his chest and arms earlier this morning. The infant was born via uncomplicated spontaneous vaginal delivery to a 28-year-old primigravida mother who had regular prenatal care and tested negative for Group B Streptococcus. He is breastfeeding vigorously and producing adequate wet diapers. Vital signs include a temperature of 37.0°C (98.6°F), heart rate of 138/min, and respiratory rate of 40/min. Physical examination reveals a well-appearing, alert neonate. Skin examination shows scattered 1- to 2-mm yellow pustules, each surrounded by a large, irregularly shaped erythematous macule. The lesions are present on the trunk, back, and proximal extremities, but the palms and soles are completely spared. No other abnormalities are noted. Which of the following is the most appropriate next step in management?