Pediatrics

Question 1

Wilms tumor

Accepted Answer

A renal tumor of embryonal origin.- Peak incidence: Children 2-5 years of age. - Associated with Beckwith-Wiedemann syndrome (hemihypertrophy, macroglossia, visceromegaly), Denys-Drash syndrome (pseudohermaphroditism, nephrotic syndrome), and WAGR syndrome (Wilms tumor, aniridia, genitourinary abnormalities, mental retardation) Clinical presentation:- Asymptomatic, nontender, smooth abdominal mass that does not usually cross the midline.- Abdominal pain, fever, hypertension, and microscopic or gross hematuria are seen. Diagnosis- Biopsy or fine-needle aspiration- Abdominal ultrasonography- CT scans of the chest and abdomen are used to detect metastases. Treatment: Local resection and nephrectomy with postsurgical chemotherapy and radiation depending on stage and histology.

Question 2

Gestational age and size

Accepted Answer

Preterm:- Premature – liveborn infants delivered prior to 37 weeks as measured from the first day of the last menstrual period- Low birth weight – birthweight < 2,500 g. This may be due to prematurity, IUGR, or both. Large for gestational age (LGA) – Fetal macrosomia:- Birth weight > 4,500 g at term- Predisposing factors: obesity, diabetes- Higher incidence of birth injuries and congenital anomalies Posterm:- Infants born after 42 weeks’ gestation from last menstrual period- When delivery is delayed ≥3 weeks past term, significant increase in mortality.- Characteristics→ Increased birth weight→ Absence of lanugo→ Decreased/absent vernix→ Desquamating, pale, loose skin→ Abundant hair,long nails→ If placental insufficiency, may be meconium staining

Question 3

Physiological changes of the newborn

Accepted Answer

Cutis marmorata = Lacy, reticulated vascular pattern over most of body when baby is cooled; improves over first month; abnormal if persists Salmon patch (nevus simplex) = Pale, pink vascular macules; found in nuchal area, glabella, eyelids; usually disappears Mongolian spots = Blue to gray macules; seen on presacral, back, posterior thighs; > in nonwhite infants; usually fade over first few years; differential: child abuse Erythema toxicum, neonatorum = Firm, yellow-white papules/pustules with erythematous base; peaks on second day of life; benign Hemangioma Superficial: bright red, protuberant, sharply demarcated; most often appear in first 2 months; most on face, scalp, back, anterior chest; rapid expansion, then stationary, then involution (most by 5–9 years of age); deeper: bluish hue, firm, cystic, less likely to regress; Rx: (steroids, pulsed laser) only if large and interfering with function

Question 4

Wet lung disease (transient tachypnea of the newborn)

Accepted Answer

Reversible respiratory disorder. Etiology:- Most commonly occurring in full-term neonates born by cesarean section in which the lungs are still filled with fluid Clinical features:- Tachypnea after birth Diagnostics:- Diffuse crackles are heard on exam- X-ray: shows fluid in the lung fissures and increased lung volumes Treatment: - Supportive care (e.g., supplemental oxygen, neutral thermal environment, adequate nutrition)- Rapid improvement generally within hours to a few days

Question 5

Meconium aspiration

Accepted Answer

Meconium passed as a result of hypoxia and fetal distress; may be aspirated in utero or with the first postnatal breath → airway obstruction and pneumonitis → failure and pulmonary hypertension. Etiology:- Usually post-term rather than preterm children Clinical features: Unresponsive neonate and green amniotic fluid Diagnostics:- Chest x-ray (best test): patchy infiltrates, increased AP diameter, flattening of diaphragm Prevention: Endotracheal intubation and airway suction of depressed infants with thick meconium Treatment:- If infant is vigorous (pulse > 100, good respiratory effort and msucle tone): Simple suctioning of the mouth then nose - If poor tone and respiratory effort or pulse < 100: Endotracheal suctioning with passage and withdrawal of an endotracheal tube - If dangerously low pulse: Positive pressure ventilation

Question 6

Diaphragmatic hernia

Accepted Answer

Failure of the diaphragm to close → abdominal contents enter into chest, causing pulmonary hypoplasia. Clinical features:- Born with respiratory distress and scaphoid abdomen- Bowel sounds may be heard in chest Diagnosis:- Prenatal ultrasound- Postnatal x-ray (best test) reveals bowel in chest Treatment:- Best initial treatment: immediate intubation in delivery room for known or suspected congenital diaphragmatic hernia- Surgical correction when stable (usually days)

Question 7

Omphalocele

Accepted Answer

Congenital herniation of abdominal viscera through the abdominal wall at the umbilicus; the hernia sac is covered by the amniotic membrane and the peritoneum. Pathophysiology: failed return of the midgut to the abdominal cavity Etiology:- Frequently observed in trisomies (trisomy 21, trisomy 13) and Beckwith-Wiedemann syndrome- Often associated with additional malformations (cardiac, gastrointestinal) Clinical features:- Often premature infants- Umbilical hernia sac (may contain intestine, liver, and gall bladder)- Features of associated conditions (see above) Diagnosis:- Primarily a clinical diagnosis at birth!- Can be detected prenatally→ Ultrasonography: polyhydramnios in utero→ Elevation of maternal serum alpha-fetoprotein (MSAFP) Complications: rupture of hernia sac with infection (peritonitis); secondary intestinal wall atresia as a result of injury Treatment:- Cesarean section to prevent rupture of the sac- Wrapping of the hernia sac with sterile saline dressings covered with plastic wrap- Nasogastric suction and administration of IV fluids to avoid abdominal distention and to compensate fluid loss- Surgery (within the first 24 h of life): usually primary abdominal wall closure

Question 8

Gastroschisis

Accepted Answer

Paraumbilical herniation of the intestine through the abdominal wall without formation of a hernia sac. Pathophysiology: - Failed formation of a sufficiently large peritoneal cavity → growing bowel leads to rupture of the anterior abdominal wall at its weakest point → herniation of bowel sections- Because the malformation occurs relatively late in development, additional anomalies are rarely present (in contrast to omphalocele) Clinical features:- Protrusion of intestinal content usually on the right side of the umbilicus; intestine not contained in a hernia sac (edematous, erythematous, and dull appearance of the bowel)- Shortened bowel, malabsorption caused by mucosal damage - Peritonitis- Seen especially in premature infants and associated with cryptorchidism and gastrointestinal stenoses or atresia Diagnosis:- Usually a clinical diagnosis!- Can be detected prenatally Treatment:- Cesarean delivery has no advantage over vaginal delivery- NG tube decompression, fluid balance- Placement of a covered silo if cannot undergo primary closure- Emergency surgery: Primary abdominal wall closure (success rate of 70%) Prognosis:- Survival rates generally good (> 90%)- Short bowel syndrome is a common complication- 20% of children develop necrotizing enterocolitis

Question 9

Physiologic vs. pathologic jaundice

Accepted Answer

Physiologic jaundice:- Appears on second to third day of life (term)- Disappears by fifth day of life (term)- Peaks at second to third day of life- Peak bilirubin <13 mg/dL (term)- Rate of bilirubin rise <5 mg/dL/d Pathologic jaundice:- May appear in first 24 hours of life- Rate of bilirubin rise >5 mg/dL/d

Question 10

Biliary atresia

Accepted Answer

Obliteration or discontinuity of the extrahepatic biliary system, most commonly of the common bile duct.- Approx. 10-35% of cases involve additional anatomical malformations (e.g., situs inversus, asplenia, polysplenia, cardiac anomalies) Clinical features:- Prolonged neonatal jaundice- Acholic stools, dark urine- Hepatomegaly Diagnostics:- Laboratory analysis: conjugated hyperbilirubinemia, mild/moderate increase in aminotransferases and alkaline phosphatase, increased GGTP- Ultrasonography (initial): absence of the gallbladder; no dilatation of the biliary tree- Liver biopsy (most accuate): active inflammation with bile duct degeneration and fibrosis- Hepatobiliary scintiscanning (HBSS): After 5-7 days of phenobarbital stimulation it shows a lack of bile reaching the duodenum- To establish definite diagnosis: intraoperative cholangiography Treatment:- Hepatoportoenterostomy (Kasai procedure): A connection is created between the liver and the small intestine to allow for bile drainage. Complications:- If undetected: early biliary liver cirrhosis (at approx. 9 weeks of age!); children may die within the first 2 years of life- Postoperative: cholangitis in 50% of cases and portal hypertension in > 60% of cases.

Question 11

Treatment of hyperbilirubinemia

Accepted Answer

Phototherapy- Complications: loose stools, erythematous macular rash, overheating leading to dehydration, and bronze baby syndrome (occurs with direct hyperbilirubinemia; dark, grayish-brown discoloration of the skin) Double volume exchange transfusion: if bilirubin continues to rise despite intensive phototherapy and/or kernicterus is a concern

Question 12

Neonatal sepsis

Accepted Answer

Risk factors:- Prematurity- Chorioamnionitis- Intrapartum fever- Prolonged rupture of membrane Common pathogens: group B Streptococcus, E. coli, Listeria Clinical features:- Irritability, lethargy, poor feeding- Jaundice- Temperature changes (fever or hypothermia)- Tachycardia, hypotension, poor perfusion, and delayed capillary refill > 3 sec- Tachypnea, dyspnea (e.g., expiratory grunting), apnea (more common in preterm infants)- Neonatal meningitis: bulging fontanelles, shrill crying, seizures, stupor- Neonatal pneumonia: Tachypnea with intercostal retractions, nasal flaring, cyanosis Diagnostics:- Blood cultures- Leukocytopenia or leukocytosis, thrombocytopenia, ↑ CRP- Urinalysis- Lumbar puncture: test cerebrospinal fluid for possible meningitis- Chest x-ray Treatment:- If no evidence of meningitis: IV ampicillin and gentamicin until 48-72-hour cultures are negative- If meningitis or diagnosis is possible: ampicillin and third-generation cephalosporin (not ceftriaxone)

Question 13

Congenital toxoplasmosis

Accepted Answer

Risk factors:- Raw or undercooked meat- Unwashed fruits/vegetables- Cat feces First trimester- ↑ Risk of premature birth and spontaneous abortion1. Chorioretinitis (form of posterior uveitis)2. Diffuse intracranial calcifications3. Signs of hydrocephalus- Nonspecific clinical features of TORCH infection: seizures, jaundice, fever, thrombocytopenia, hepatosplenomegaly, lymphadenopathy, pneumonitis, purpuric rash Sequelae:- Epilepsy- Intellectual disability- Visual disabilities (chorioretinitis → increased risk of cataracts, glaucoma) Diagnostics:- Fetus: PCR for T. gondii DNA in amniotic fluid - Newborn: CT/MRI: intracranial calcifications, hydrocephalus, ring-enhancing lesions- T. gondii-specific IgM antibodies, PCR for T. gondii DNA (CSF, serum)- Ophthalmological evaluation: chorioretinitis Treatment:- If a pregnant woman is newly diagnosed with toxoplasmosis: immediately treat with spiramycin- If fetal infection: Pyrimethamine, sulfadiazine, and folinic acid

Question 14

Congenital rubella

Accepted Answer

Risk of congenital rubella syndrome:- Infection from 1-11 weeks' gestation → 90% risk- Infection between 16-20 weeks' gestation → very low risk (< 1%)- Infection at > 20 weeks' gestation → no documented cases of congenital rubella syndrome Clinical features:- Miscarriage, preterm birth, fetal growth restriction, especially if infection occurs during the first trimester1. Cataracts 2. Cochlear defect → bilateral sensorineural hearing loss3. Cardiac defect: Patent ductus arteriosus, pulmonary artery stenosis4. Blueberry muffin spots (extramedullary hematopoeisis, thrombocytopenia) Diagnosis:- PCR for rubella RNA (throat swab, CSF)- Serology (IgM antibodies, IgG antibodies in abnormally high or persistent concentrations)- Viral culture (nasopharynx, blood)- Fetus: IgM antibody serology (chorionic villi, amniotic fluid), PCR for rubella RNA (chorionic villi, amniotic fluid) Treatment:- Intrauterine rubella infection < 16 weeks: counsel to terminate pregnancy- > 16 weeks: reassurance

Question 15

Congenital cytomegalovirus

Accepted Answer

Clinical features:1. Intrauterine growth restriction2. Periventricular calcifications (vs. intraventricular in toxoplasmosis)3. Microcephaly- Chorioretinitis, thrombocytopenia, hepatosplenomegaly Diagnostics:- CMV IgM antibodies (blood)- Viral culture or PCR for CMV DNA (urine, saliva) Treatment:- Fetus: intrauterine blood and platelet transfusions for severe anemia and thrombocytopenia- Newborns and pregnant women: Antivirals: ganciclovir (IV) and valganciclovir (oral)

Question 16

HSV infection of the newborn

Accepted Answer

Clinical features:- Intrauterine infection (∼ 5% of cases)→ Preterm birth, very low birth weight→ Microcephaly, hydrocephalus, and other CNS defects→ Microphthalmia → eye damage and chorioretinitis→ Vesicular skin lesions- Perinatal (85% of cases) und postnatal transmission (10% of cases)→ Skin, eye, and mouth disease (∼ 45%): vesicular skin lesions, keratoconjunctivitis → cataracts and chorioretinitis, vesicular lesions of the oropharynx→ CNS disease (∼ 30%): meningoencephalitis Diagnostics:- Viral culture of HSV from skin lesions, conjunctiva, oro- or nasopharynx, rectum- PCR for HSV DNA (CSF, blood) Treatment:- For both neonates and pregnant women: IV acyclovir or valaciclovir Prevention:- If a history of HSV lesions are known → antiviral therapy (acyclovir) beginning at 36 weeks of gestation- Cesarean section in women with active genital lesions or prodromal symptoms (e.g., burning, pain)

Question 17

Congenital syphilis

Accepted Answer

Transplacental transmission usually during second half of gestation Early congenital syphilis (onset prior to 2 years of age):- Hepatomegaly and jaundice- Rhinorrhea with white or bloody nasal discharge (“snuffles”)- Maculopapular rash on palms and soles - Skeletal abnormalities (e.g., metaphyseal dystrophy, periostitis)- Generalized lymphadenopathy (nontender) Late congenital syphilis (onset after 2 years of age):- Typical facial features: saddle nose, frontal bossing, short maxilla- Dental findings: Hutchinson teeth (notched, widely spaced teeth) and mulberry molars (poorly developed first molars)- Eyes and ears: interstitial keratitis, sensorineural hearing loss, and other abnormalities- Skin: rhagades (perioral fissures), gummas- Skeletal: “saber shins” (anterior bowing of the tibia)- Neurological: cranial nerve defects, intellectual disability, hydrocephalus Diagnostics:- Initial test: RPR or VDRL (serum)- Confirmatory test: darkfield microscopy or PCR of lesions or bodily fluids Treatment: IV penicillin G for both pregnant women and newborns

Question 18

Congenital varicella

Accepted Answer

Congenital varicella syndrome (infection during the first and second trimester):- Hypertrophic scars (cicatricial skin lesions)- Limb defects (e.g., hypoplasia)- Ocular defects (e.g., chorioretinitis, cataracts, microphthalmus)- CNS defects (e.g., cortical atrophy, seizures, intellectual disability) Neonatal varicella:- Mild infection (maternal exanthem > 5 days before birth)- Severe infection (maternal exanthem < 5 days before birth): hemorrhagic exanthem, encephalitis, pneumonia, or congenital varicella syndrome (mortality rate of up to 30%) Treatment:- For pregnant women or newborns with severe infection: acyclovir- Administer postexposure prophylaxis in newborn infants if the mother displays symptoms of varicella < 5 days before delivery (varicella-zoster immune globulin, or VZIG)

Question 19

Intraventricular hemorrhage

Accepted Answer

Risk factors:- Birth weight < 1500 g and delivery before 32 weeks' gestation- Maternal chorioamnionitis- Hypoxia during or after birth Clinical features:- Usually occurs within 5 days of birth- Most infants are asymptomatic, but saltatory (over several days) or, more rarely, catastrophic (over minutes to hours) courses are also possible- Lethargy, hypotonia, irregular respirations, seizures, bulging anterior fontanelle- Cranial nerve abnormalities (e.g., pupils react sluggishly to light) and changes in eye movement (e.g., roving eye movements) Diagnosis:- Cranial ultrasound- Since most patients are asymptomatic, screening ultrasounds are routinely performed in infants with a birthweight < 1500 g and delivery before 30 weeks gestation. Treatment:- Intracranial pressure (ICP) monitoring via an intraventricular catheter and medications to maintain ICP, blood pressure, and coagulation

Question 20

Beckwith-Wiedemann syndrome

Accepted Answer

Congenital disorder of growth with a predisposition to tumor development. Pathogenesis: Deregulation of imprinted gene expression in chromosome 11p15 Clinical features:- Fetal macrosomia, rapid growth until late childhood- Macroglossia- Omphalocele - Organ enlargement (heart, liver, kidney, etc.)- Hemihypertrophy- Earlobe creases and pits, midfacial hypoplasia- Pancreatic beta cell hyperplasia – excess islets → hypoglycemia Complications: Wilms tumor, hepatoblastoma, neuroblastoma Diagnosis:- ↓ Blood glucose, ↑ serum insulin, IGF-2 (hypoglycemia)- Abdominal ultrasound (embryonal tumors) Treatment:- Frequent feedings to maintain sufficient blood glucose levels - Obtain ultrasounds and serum AFP every 6 months through 6 years of age to look for Wilms tumor and hepatoblastoma- Resection of embryonal tumors

Question 21

Fetal alcohol syndrome

Accepted Answer

Epidemiology:- Most common cause of teratogenic damage in children (1:500-1000)- Most common cause of intellectual disability in the US! Pathophysiology: failed cellular migration Clinical findings:- Dysmorphic features: Thin upper lip, smooth hypoplastic philtrum, down-slanting, short palpebral fissures, narrow, receding forehead, hypertelorism, epicanthal folds, receding chin, microcephaly- Growth restriction- Heart defects (mainly ventricular septal defect)- Skeletal anomalies (limb dislocations, joint contractures, pectus excavatum/carinatum)- Prenatal or postnatal growth retardation, leading to short stature- Holoprosencephaly- Hyperactivity, intellectual disability (e.g., learning disabilities, memory and reasoning deficits, and impaired language development) → problems in social interactions and school performance

Question 22

Enuresis

Accepted Answer

Repeated involuntary elimination of urine that is inappropriate for developmental age (e.g., pants- or bed-wetting). Epidemiology: Affects 5-10% of 5-year-oldsNormal up until age 7. Etiology:- Risk factors: psychosocial stressors (e.g., recent move, sexual abuse, conflicts in the family), positive family history- Associations: other psychiatric disorders, e.g., ADHD, conduct disorders, autism Diagnostic criteria:- Occurs 2x/week for ≥ 3 months or causes clinical distress- Patient's developmental age must be ≥ 5 years- Symptoms not caused by a medication or another medical condition Types:- Nocturnal (♂ > ♀) or diurnal (♀ > ♂)- Primary (patient never achieved continence) or secondary (onset of symptoms after patient had achieved continence) Treatment:- Organic causes (e.g., urinary tract infections, urinary tract abnormalities, renal disorders) must be excluded before any treatment is started.- First-line: → Psychoeducation→ Parent management training→ Fluid restriction at night→ Behavioral training with a urine alarm- Second-line: pharmacological treatment (e.g., desmopressin, imipramine)

Question 23

Retinopathy of prematurity

Accepted Answer

Disease of the retina with abnormal vessel proliferations that affects preterm infants. Pathophysiology: Elevated and fluctuating partial pressures of oxygen → pathological extraretinal neovascularization → hemorrhages, formation of fibrovascular membranes, and, in severe cases, retinal detachment. Risk factors:- Premature birth- Ventilation or oxygen administration- Birth weight < 1500 g- Blood transfusions Clinical features: only in severe cases of leukocoria Diagnostics: Screening of all premature babies that are at risk for developing ROP- Indications:→ Gestational age of < 32 weeks or if gestational age is unknown and birth weight ≤ 1500 g (regardless of oxygen administration)→ Gestational age between 32-36 weeks if oxygen has been administered for more than 3 days after birth- Timing of examinations:→ First examination 6 weeks postnatally- The examination of the ocular fundus assesses the following:→ Vascularization of the peripheral retina→ Demarcation line between vascularized and nonvascularized retina→ Extraretinal vessel formations→ Formation of membranes and distortion/detachment of the retina→ Plus disease: increased tortuosity, exudation, hemorrhage Treatment:- In early stages of the disease: no treatment, but regular follow-up- In advanced stages: laser coagulation therapy may be indicated- In onset of retinal detachment: vitrectomy may be indicated

Question 24

Bronchopulmonary dysplasia

Accepted Answer

Chronic lung disease primarily found in premature infants exposed to prolonged mechanical ventilation and oxygen therapy for neonatal RDS. Etiology: immature lung with exposure to ventilation → barotrauma, oxygen toxicity, inflammation Clinical features:- Seen in infants < 32 weeks- History of infant requiring mechanical ventilation > 28 days to maintain PaO2 above 50 mm Hg; oxygen demand usually increases over time - Persistence of symptoms similar to NRDS (e.g., tachypnea, grunting, nasal flaring); episodes of desaturation Diagnostics:- Chest x-ray: diffuse, fine granular densities; atelectasis- Histology: atelectasis, fibrosis, emphysematous alveolar changes Therapy: controlled oxygenation, high-calorie food, diuretics, consider glucocorticoids

Question 25

Breastfeeding jaundice vs breast milk jaundice

Accepted Answer

Breastfeeding jaundice:- Pathophysiology: insufficient breast milk intake → lack of calories and inadequate quantities of bowel movements to remove bilirubin from the body → ↑ enterohepatic circulation → increased reabsorption of bilirubin from the intestines- Timing: onset within 1 week- Signs of dehydration- Treatment: increase breastfeeding sessions, rehydration Breast milk jaundice:- Pathophysiology: increased concentration of β-glucuronidase in breast milk → inhibits glucuronyl transferase → ↑ deconjugation and reabsorption of bilirubin → persistence of physiologic jaundice- Timing: onset within 2 weeks after birth; lasts for 4-13 weeks - Normal examination- Treatment→ Continued breastfeeding and supplementation with formula feeds → Phototherapy if required

Question 26

Bladder exstrophy

Accepted Answer

Embryological defect of ventral abdominal wall due to an overdeveloped cloacal membrane Epidemiology: M > F Clinical features:- Bladder and urethra herniated through defect in abdominal wall- Incontinence- Males: shortened penis with dorsal penile curvature and epispadias- Females: bifid clitoris with labia separated anteriorly and epispadias- Widely separated pubic symphysis- Associated malformations: → Omphalocele→ Often a low set umbilicus, indirect inguinal hernia, and anteriorly displaced anus Diagnosis: Largely a clinical diagnosis- Prenatal ultrasound with inability to visualize bladder, lower abdominal wall mass, low set umbilical cord, abnormal genitalia, and pubic bone diastasis Treatment:- Surgical repair and reconstruction within 2 days to 2 weeks- Iliac osteotomy may be required if the diastasis is extreme

Question 27

Neural tube defects

Accepted Answer

Etiology:- Maternal folic acid deficiency during pregnancy; disorders or drug intake affecting folate metabolism- Concomitant chromosomal aberrations (e.g., trisomy 13 and 18)- Associated maternal conditions: diabetes mellitus, obesity, fever/hyperthermia during first trimester- Arnold-Chiari II: Associated with myelomeningocele Diagnostics:- Prenatal screening→ Elevated levels of alpha-fetoprotein (AFP) in amniotic fluid at 13-15 weeks' gestation→ Fetal ultrasonography at 20 weeks' gestation- CT scans and cranial ultrasonography (in infants) to monitor possible hydrocephalus- MRI for assessment of spinal cord malformations Treatment - The baby is usually delivered by cesarean section. - Prophylactic administration of broad-spectrum antibiotics- Surgical closure within 72 hours after birth Prevention - Folic acid supplementation: 400-800 μg/day at least 4 weeks prior to a planned pregnancy- Intake should continue through the first trimester.- Women who have had a child with an NTD or have one themselves should take 4 mg/day starting 4 weeks prior to trying to conceive.

Question 28

Anal atresia

Accepted Answer

Sporadically occurring malformation of the rectum with absence of an anal opening Associated conditions: Down syndrome, VACTERL syndrome, additional malformations Clinical features:- Flat bottom (no or poorly developed midline groove between buttocks), absence of anal opening- Thin anal membrane in place of anal opening through which meconium is visible- Patients may present with obstipation and ileus, or develop fistulas which enable limited defecation (e.g., rectourethral, rectovaginal). Diagnosis: Clinical - Cross table x-ray of prone child with radiopaque perineal marking: Gives relationship between gas bubble and anus Treatment:- IV hydration, no oral feeding- Low lesions: Dilation or minor surgical procedure- High lesions: Colostomy with future correction- Evaluation for VACTERL: Sacral ultrasound, x-ray, VCUG, NG tube passage, echocardiogram

Question 29

Meconium ileus

Accepted Answer

Failure to pass the first stool in in the first 24-48 hours after birth. Etiology: - Cystic fibrosis is the leading cause in (> 90%) of cases.- Imperforate anus- Hirschsprung's disease Clinical findings: signs of a distal small bowel obstruction- Bilious vomiting- Abdominal distention- No passing of meconium or stool Diagnostics: Abdominal x-ray (with contrast agent)- Dilated small bowel loops, microcolon, Neuhauser sign ("soap bubbles" effect)- Air-fluid levels are uncommon because of the viscous consistency of meconium Treatment:- Enema with a contrast agent- Surgery is required in complicated cases: intestinal perforation or volvulus- Small bowel obstruction may also occur in older children and adults.

Question 30

Laryngomalacia

Accepted Answer

Epidemiology:- Most common cause of congenital stridor- Symptoms begin within the first 2 months of life and peak at 6-8 months Pathophysiology: Collapse of supraglottic structures during inspiration → airway obstruction Clinical features:- Usually happy and thriving infants- Inspiratory stridor that worsens in supine position- Reflux may be present- Failure to thrive and sleep-disordered breathing in severe cases Diagnosis: - Flexible laryngoscopy: collapse of supraglottic structures during inspiration and omega-shaped epiglottis Treatment:- Reassurance (resolves by age 2 years in 90% of cases)- Supraglottoplasty in severe cases (e.g., severe hypoxemia, apnea, pulmonary hypertension, failure to thrive)

Question 31

Foreign body aspiration

Accepted Answer

Accidental aspiration of a foreign body (e.g., nuts, raisins, seeds, pieces of toys). Clinical features:- Sudden onset- If the initial aspiration and choking episode is not witnessed, onset of symptoms (persistent or recurrent cough) days or weeks later- Complete airway obstruction: respiratory distress, cyanosis, altered mental state- Partial airway obstruction: does not appear toxic; may develop symptoms of complications (aspiration pneumonia, lung abscess)- Choking Diagnostics: X-ray- Most FB are radiolucent; focal overinflation of the distal lung may be visible- Approx. 16% of FB in larynx or trachea and 60% in the right lung Treatment:- Removal of FB via rigid bronchoscopy- Heimlich maneuver if the child is in respiratory distress and cannot speak or cry

Question 32

Pneumonia

Accepted Answer

Bacterial: S. pneumoniae, HIB, S. aureus- Any age- Acute, severe- Productive cough- CXR = lobar consolidation- Admit for IV cefuroxime Viral: RSV, Parainfluenza, Influenza, Adenovirus- Most common form <5 years- CXR = bronchopneumonia, interstitial C. trachomatis- Age 1-3 months- May have had conjunctivitis as newborn- Afebrile- Staccato cough- CXR = mild interstitial- Eosinophilia- Oral macrolide M. pneumoniae, C. pneumoniae- Most common form age >5 years- CXR = most unilateral lower lobe interstitial; looks worse than symptoms- Oral macrolide

Question 33

Cystic fibrosis

Accepted Answer

Autosomal recessive disorder caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene on chormosome 7. Clinical features:- Meconium ileus- Failure to thrive- Pancreatic disease- Liver and bile duct disease- Obstructive lung disease with bronchiectasis- Chronic sinusitis; nasal polyps may eventually develop- Recurrent or chronic productive cough and pulmonary infections with characteristic microorganisms- Salty-tasting sweat → electrolyte wasting- Frequent fractures because of osteopenia- Nephrolithiasis, nephrocalcinosis- Infertility Diagnositcs:- Neonatal screening: ↑ Immunoreactive trypsinogen (IRT)- Sweat chloride test (best initial test): Sweat chloride ≥ 60 mmol/L on two occasions- DNA analysis- Nasal potential difference test Treatment:- Hypertonic saline nebulization or dornase alpha- Bronchodilator therapy (e.g., albuterol)- Chest physiotherapy- Mucolytics (e.g., N-acetylcysteine)- Pancreatic enzyme supplements- Oral supplementation of lipophilic vitamins A, D, K, and E- Treatment of pulmonary infections→ S. aureus, H. influenzae → IV vancomycin→ Pseudomonas aeruginosa, Burkholderia cepacia → inhaled tobramycin→ Aspergillus → Itraconazole or voriconazole PO

Question 34

Sudden infant death syndrome (SIDS)

Accepted Answer

Sudden infant death syndrome (SIDS) is the abrupt and unexplained death of an infant less than 1 year old. Risk factors:- Peak incidence: 2-6 months- Sleeping in the prone position- Highest in winter, midnight to 9 A.M.- Males > females- Exposure to smoking- Unsafe sleeping environment or CO2 rebreathing: e.g., a shared blanket, stuffed animals in the crib (because of the grasping reflex, newborns tend to drag items to their faces)- Overheating- Many more correlations: SIDS in siblings, babies born prematurely, young mothers (< 16 years), low socioeconomic status, etc. Counseling:- Place babies on their backs on a firm surface for sleep- No pillows, loose bedding, or blankets in the crib- No bed-sharing- Use of a pacifier can reduce the risk of SIDS

Question 35

Anaphylaxis

Accepted Answer

Clinical features:- Skin or mucous membranes: flushing, urticaria, pruritus, erythema, swelling of the eyelids, or angioedema- Respiratory: nasal congestion, cough, sneezing, hoarseness, chest tightness, dyspnea- Cardiovascular: hypotension, tachycardia, chest pain- GI: abdominal pain, nausea, and vomiting (especially in food allergies) Criteria for diagnosis:- Acute onset (within 1 hour of exposure)- Likely exposure to an allergen- Reduced blood pressure after exposure to a known allergen Treatment:1. Withdrawal of offending agent if applicable (e.g., in drug reactions)2. Airway: examination of airway and intubation if obstruction seems imminent3. Epinephrine IM4. Positioning: The patient should be placed in a recumbent/supine position with elevation of the lower extremities.5. O2 by facemask6. If patient is hypotensive: volume replacement – normal saline 1-2 L IV rapid bolus 7. Bronchospasm and no benefit of epinephrine: nebulized albuterol (salbutamol)8. Antihistamines- H1 antihistamine (e.g., diphenhydramine) IV for urticaria- H2 antihistamine (e.g., ranitidine) IV9. Methylprednisolone10. Continuous monitoring of blood pressure, heart rate, heart function, and pulse oximetry; urine output should also be monitored in hypotensive patients receiving resuscitation.

Question 36

Allergic rhinitis

Accepted Answer

Acute or chronic rhinitis caused by exposure to an inhaled allergen. Etiology:- Type I hypersensitivity reaction- Genetic predisposition to atopy Clinical features:- Recurrent episodes of sneezing, nasal congestion, rhinorrhea, and post-nasal drip- Itchy nose and throat- Pale, boggy nasal mucosa with hypertrophic turbinates, and/or nasal polyps - Congestion underneath the eyes ("allergic shiners")- Transverse nasal crease ("allergic salute")- Cobblestone appearance of the posterior pharyngeal wall- Associated allergic conditions: Allergic conjunctivitis, atopic dermatitis and/or bronchial asthma Diagnostics: Clinical- RAST (radioallergosorbent test): measures serum concentrations of IgE antibodies against a specific allergen- Prick and intradermal tests to identify the allergen Treatment:- Avoid exposure to the putative allergen (e.g., allergen, dust).- 1st line: Intranasal sprays: Corticosteroids, antihistamines- Oral drugs: Antihistamines, leukotriene antagonists- 2nd line: controlled exposure to gradually increasing doses of the allergen in order to hyposensitize the IgE response (immunotherapy)

Question 37

Malrotation

Accepted Answer

Intestinal malrotation: Arrest in the normal rotation of the gut in utero, resulting in an abnormal orientation of the bowel and mesentery within the abdominal cavity. Midgut volvulus: Torsion of a malrotated midgut causing mechanical bowel obstruction, mostly in neonates and infants. Clinical features:- Malrotation: mostly asymptomatic- Midgut volvulus: Bilious vomiting - Signs of bowel ischemia: hematochezia, hematemesis, hypotension, and tachycardia- Variable presentation in older children/adults: recurrent episodes of abdominal pain and vomiting; failure to gain weight; malabsorption Diagnostics:- Upper GI series Differential diagnoses:- In neonates/infants with recurrent vomiting: duodenal atresia and stenosis, hypertrophic pyloric stenosis- In neonates with features of bowel ischemia/gangrene: necrotizing enterocolitis (NEC)- In older children with abdominal pain and vomiting: intussusception Treatment:- Nil per oral; nasogastric tube insertion; IV fluids; correction of electrolyte imbalance; broad-spectrum IV antibiotics- Emergency surgery (Ladd procedure)

Question 38

Duodenal atresia

Accepted Answer

Epidemiology:- ∼ 50% of cases are associated with further anomalies, e.g., bile duct and VACTERL association.- 30% of cases are associated with chromosomal abnormalities, especially Down syndrome. Pathophysiology: Recanalization of the closed duodenum fails to occur during the embryonic period (usually between the 8th-10th week of gestation). Clinical features - Intrauterine: Polyhydramnios- Postpartum→ Vomiting, that is typically bilious if the stenosis is distal to the major duodenal papilla→ Atresia or high-grade stenosis: vomiting few hours after birth→ Mild stenosis: vomiting after a few days→ Distended upper abdomen and scaphoid lower abdomen→ Delayed meconium passage Diagnostics:- X-ray of the abdomen: Double bubble sign; Gasless distal bowel Treatment:- Parenteral nutrition via a central catheter shortly after birth- Fluid replacement and restoration of the electrolyte balance- Gastric decompression- Surgery: bypass the atresia or stenosis

Question 39

Jejunal atresia

Accepted Answer

Absence of the jejunal lumen Epidemiology: less common than duodenal atresia Pathophysiology: Vascular accident in utero → necrosis and reabsorption of the jejunum Risk factors: Vasoconstrictive drugs (e.g., cocaine, MDMA, or cigarettes) during pregnancy Clinical features: similar to duodenal atresia- Polyhydramnios (intrauterine)- Bilious vomiting and upper abdominal distension (postpartum) Diagnosis: - X-ray shows a triple bubble sign and gasless colon Treatment: surgical correction with bypass of the occluded part of bowel is always required

Question 40

Esophageal atresia

Accepted Answer

Classification: GrossType A: Esophageal atresia without tracheoesophageal fistula (∼ 8%)Type B: Esophageal atresia with tracheoesophageal fistula to the proximal esophageal segment (∼ 3%) Type C: Esophageal atresia with tracheoesophageal fistula to the distal esophageal segment (∼ 84%)Type D: Esophageal atresia with tracheoesophageal fistula to the proximal and distal esophageal segments (∼ 1%)Type E: H‑type tracheoesophageal fistula without atresia (∼ 4%) Clinical features: - Prenatal: Polyhydramnios → increased risk of premature birth- Esophageal atresia → pooling of secretions → excessive secretions/foaming at the mouth- Tracheoesophageal fistula: If the fistula is connected to the proximal esophageal segment: aspiration and subsequent aspiration pneumonia→ Coughing spells→ Rales→ Cyanotic attacks- If the fistula is connected to the distal esophageal segment: gastric distention Diagnostics:- Placement of a feeding tube: the feeding tube cannot pass through the esophagus in the case of esophageal atresia- X-ray of the thorax/abdomen:→ Esophageal pouch (except with an H‑type fistula) → Gross types A and B present with a gasless abdomen- Further diagnostics concerning VACTERL anomalies: Ultrasound of the abdomen; Echocardiography

Question 41

Otitis externa

Accepted Answer

Etiology:- Bacterial infections: Pseudomonas aeruginosa (∼ 40% of cases, commonly from swimming activities), Staphylococcus aureus, Proteus mirabilis, Escherichia coli- Fungal infections: Aspergillus Risk factors:- Injury to the skin of the external auditory canal (e.g., cleaning, insertion of foreign objects such as hearing aids or earplugs, excessive itching)- Increased moisture in the external auditory canal (e.g., swimming, humid climate) Clinical features:- Severe ear pain, particularly at night- Otorrhea- Intense itching in the external auditory canal- The tragus is tender to touch- Pulling up and back on the auricle causes pain- Conductive hearing loss- Otoscopic findings: Furuncle (localized); edematous and reddened external auditory canal (diffuse) Diagnostics: Clinical - Check blood glucose levels to rule out diabetes Treatment:- Topical treatment→ Antibiotic eardrops (typically ofloxacin, ciprofloxacin, or gentamycin) → Topical hydrocortisone to control itching and inflammation→ Aural toilet: clean the external auditory canal and keep it dry using an ear wick and/or astringents (e.g., mixture of isopropyl alcohol and acetic acid)- Systemic treatment: oral ciprofloxacin→ Indications: Immunosuppression, diabetes mellitus, severe otitis externa with cellulitis - NSAIDs for pain relief

Question 42

Mastoiditis

Accepted Answer

Epidemiology: often occurs in children < 5 years Clinical features:- Persistence/recurrence of otalgia and fever after initial improvement- Fever- Ear discharge becomes profuse (discharge persisting > 3 weeks suggests mastoiditis)- Tender and edematous mastoid- Ear displaced laterally and forward- In advanced stages, the retroauricular sulcus is obliterated and the ear can be pushed forward Diagnostics:- Otoscopy: The TM may be perforated- First test: CT scan of the temporal bone Treatment:- Antibiotic treatment is always indicated→ Vancomycin alone: in patients who have not recently received antibiotics and who do not have a history of recurrent AOM→ Vancomycin + ceftazidime or cefepime or piperacillin-tazobactam: patients who recently recieved antibiotics and/or had an episode of AOM within the past 6 months→ Tympanostomy (myringotomy) + tympanostomy tube insertion: for early stages of mastoiditis→ Mastoidectomy: is indicated in severe cases that do not improve with antibiotics + tympanostomy

Question 43

Sinusitis

Accepted Answer

Pathogens:- Viral (most common): rhinovirus, coronavirus, adenovirus, influenza, and parainfluenza viruses- Bacterial: S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus- Fungal: Aspergillus, Rhizopus oryzae Clinical features:- Fever (∼ 50% of cases), headaches, general malaise, myalgia- Facial pain or pressure, erythema, and swelling over the affected area due to inflammation→ Maxillary sinuses: over the cheeks (mimics dental pain)→ Frontal sinuses: lower forehead→ Ethmoidal sinuses: nasal bridge and/or between the eyes or retro-orbital pain→ Sphenoid sinuses: located in the sphenoid bones near the optic nerve and pituitary gland. These are the most posterior sinuses. Diagnostics - Diagnosis of acute cases is usually established clinically. However, imaging or endoscopy should be considered if symptoms fail to improve within 7 days of diagnosis.- Laboratory tests: to determine underlying condition if suspected (e.g., nasal cytology allergic rhinitis, HIV test, sweat chloride test for cystic fibrosis)- X-ray of sinuses (poor sensitivity): decreased transparency of sinus, air-fluid levels may be seen - CT of sinuses (imaging modality of choice)- Nasal endoscopy Treatment:- Viral: Usually self-limiting- Bacterial: Amoxicillin, with or without clavulanate for 5-10 days

Question 44

Choanal atresia

Accepted Answer

Congenital condition characterized by a bony (90% of cases) and/or membranous (10%) obstruction of the posterior nasal passage Epidemiology:- Unilateral choanal atresia is twice as common as bilateral choanal atresia.- Frequently associated with other anomalies (“CHARGE syndrome” - coloboma, heart defects, atresia choanae, retardation of growth, genital abnormalities, and ear abnormalities) Etiology:- Thyroid medications (methimazole, carbimazole)- Cigarette smoking- Caffeine (≥ 3 cups per day)- Elevated levels of vitamin B12, zinc, and vitamin B3 (niacin) Clinical features:- Infants are only able to breathe through the mouth (immediately postpartum)- Cyanosis that worsens when feeding and improves when crying- Upper airway obstruction (e.g., noisy breathing, dyspnea)- Food intake impossible: Complete airway obstruction is a life-threatening condition immediately following birth because of the worsening dyspnea associated with feeding. Diagnostics:- The inability to pass the catheter through the nasal cavity is an indication of choanal atresia.- Confirmatory tests: contrast rhinography in the supine position or CT scan Treatment: - Urgent insertion of an oropharyngeal airway (or even intubation) as a temporary airway until surgery- Surgical perforation- Local use of chemotherapeutic agents (e.g., mitomycin C) may reduce the need for stenting, dilatations, and a second surgery.

Question 45

Febrile seizures

Accepted Answer

Seizures that are associated with fever (mainly temperatures exceeding 38°C) in the absence of CNS infection, metabolic abnormalities, or a history of afebrile seizures. Epidemiology:- Peak incidence: 2nd year of life; most commonly occurs between 6 months and 5 years of age- Prevalence: Febrile seizures occur in ∼ 4% of all children. Diagnostics:- Simple febrile seizures do not require specific diagnostic workup- Diagnostic examination focuses on identifying the cause of fever- Complex febrile seizures always require specific investigative tests (e.g., EEG and imaging).- In suspected cases of intoxication: toxicology screen Treatment:- Uncomplicated seizures usually resolve after a few minutes spontaneously. However, abortive therapy should be administered if seizures ≥ 5 min or complex.- Abortive therapy: IV lorazepam- Reassure caregivers and provide information- After a febrile seizure, initiate antipyretic therapyIf a seizure is focal, >15 min duration, or recurrent within the day, investigation for complex febrile seizure needs to happen (EEG, MRI, LP based on clinical suspicion). Prognosis:- The risk of recurrent, simple febrile seizures is 30%.- Risk of developing epilepsy: ∼ 1-2% in children who have had a simple febrile seizure- 5-10% in children with complex febrile seizures or a family history of epilepsy

Question 46

Infantile spasms (West syndrome)

Accepted Answer

Epidemiology:- Age at onsest: 3-7 months- Sex: ♂ > ♀ Etiology:- Perinatal infections- Hypoxic-ischemic injury- PKU- Tuberous sclerosis complex- Idiopathic Clinical features:- Sudden symmetric, synchronous spasms, usually in clusters of 5-10- Jerking flexion (jackknife movement) or extension of the neck, torso, and extremities- Followed by a tonic phase EEG:- Hypsarrhythmia: characteristic finding in interictal EEG; high-voltage delta waves with irregular multifocal spikes and slow waves- Ictal EEG: very heterogeneous Treatment:- First-line: ACTH, prednisone, or vigabatrin Prognosis: Neurodevelopmental delay, regression of psychomotor abilities in > 85% of cases

Question 47

Lennox-Gastaut syndrome

Accepted Answer

Epidemiology:- Age at onset: 3-5 years- Sex: ♂ > ♀ Etiology:- Majority of cases due to structural brain abnormalities- 40% of cases are cryptogenic Clinical features:- Multiple types of seizures: myoclonic, tonic, atonic, absences- Developmental delays- Frequently periods of status epilepticus EEG:- Multifocal sharp and slow waves- Abnormal interictal EEG: slow spike-wavepattern Treatment:- Attempt anticonvulsive treatment, e.g., valproic acid, clobazam, lamotrigine- Ketogenic diet, vagus nerve stimulation, surgery Prognosis: Poor; Developmental delay, cognitive impairment, and psychotic symptoms

Question 48

Tuberous sclerosis

Accepted Answer

Autosomal dominant neurocutaneous syndrome. Clinical features:- Intellectual disability (caused by brain lesions)- Infantile spasms or seizures - Adenoma sebaceum: reddish nodules in a butterfly appearance around the nose and cheeks (facial angiofibroma); acne-like appearance- Ash-leaf spots- Shagreen patch - Brain tumors: Hamartomas; Giant cell astrocytoma- Cardiac rhabdomyoma (> 50% of patients→ symptoms of congestive heart failure)- Renal cysts or renal angiomyolipoma- Ungual fibromas Diagnostics:- ECG: cardiac rhabdomyoma (ventricular hypertrophy, arrhythmias)- EEG: seizure activity- Abdominal MRI: renal angiomyolipoma- cCT/MRI: brain tumors- TSC1 mutation on chromosome 9 or TSC2 mutation on chromosome 16 (tumor suppressor genes) Treatment:- Anticonvulsants and adrenocorticotropic agents (e.g., prednisone) for seizure control and infantile spasms- Removal of angiofibromas (laser treatment/electrosurgery)- Immunosuppressants (e.g., mTor inhibitors like sirolimus, everolimus) to treat renal angiomyolipoma and inoperable giant cell astrocytoma

Question 49

Absence epilepsy

Accepted Answer

Epidemiology:- Age at onset: 6-7 years- Sex: F > M Clinical features:- Absence seizures lasting 5-10 secondsup to 100x/day- Brief unresponsiveness without convulsions- Amnestic during seizures; children appear to be staring or daydreaming- Lip smacking, eye fluttering or head nodding are common- No postictal phase Triggers: hyperventilation, lights EEG:- 3 Hz spikes and waves in all regions of the brain Treatment:- 1st line: Ethosuximide- 2nd line: Sodium valproate Prognosis:- 80% of children are seizure-free with treatment- Usually subsides before adulthood

Question 50

Developmental dysplasia of the hip

Accepted Answer

Developmental dysplasia of the hip (DDH) refers to hip instability, subluxation/dislocation of the femoral head, and/or acetabular dysplasia in a developing hip joint. Risk factors:- Family history- Breech presentation- Inadequate intrauterine space for the fetus (e.g., oligohydramnios, first born child, twins, large birth weight) - Diseases associated with ligamentous laxity Clinical features:< 6 months: Asymptomatic- Barlow and Ortolani signs6-18 months- Inability to abduct the hip- Barlow and Ortolani sign disappear- Asymmetrical gluteal folds may be present> 18 months- Hip pain, and/or pain referred from the hip to the knee and/or anterior thigh- Possibly a hip deformity (e.g., coxa vara)- Waddling or Trendelenburg gait- Leg length discrepancy and toe walking to compensate for the difference in leg length Diagnostics:- Screening: Physical examination must be performed at every well-baby visit for up to 6 months- Hip ultrasound: imaging of choice in all infants younger than 4 months- Hip x-ray (in AP and frog-leg lateral view): imaging of choice in infants older than 4 months Treatment:< 6 months: rigid brace that maintains the hips in flexion and abduction< 6 months: Pavlik harness (most commonly used splinting device)6-18 months: closed reduction followed by immobilization with a hip spica cast> 18 months: surgical therapy (open reduction possibly with a pelvic/femoral osteotomy) followed by immobilization with a hip spica cast

USMLE Step 2 (Fach) / Pediatrics (Lektion)