Pediatrics Flashcards
Reye syndrome
Rare, often fatal childhood hepatic encephalopathy. Findings: mitochondrial abnormalities, fatty liver (microvesicular fatty changes), hypoglycemia, vomiting, hepatomegaly, coma. Associated w/ viral infection (especially VZV and influenza B) that has been treated with aspirin. Mechanism: a. mitochondrial damage b. disruption of urea cycle (normally used to metablize ammonia); causes increase in serum ammonia c. aspirin metabolites decrease beta-oxidation by reversible inhibition of mitochondrial enzymes; more FA become available to synthesize TG. *Avoid aspirin in children, except for those w/ Kawasaki disease (FA p 369, Goljan pp 533-34)
Kawasaki disease
Necrotizing medium-vessel vasculitis affecting Asian children <4 yo; likely has infectious etiology that precipitates immune rxn in genetically susceptible individuals. Mucocutaneous lymph node syndrome: Conjunctival injection, Rash (polymorphous –> desquamating), Adenopathy (cervical), Strawberry tongue (oral mucositis), Hand-foot changes (edema, erythema): CRASH and burn mnemonic. May develop coronary artery aneurysm; thrombosis or rupture can cause death. Treat w/ IVIG and aspirin. FA pp 302-303; Goljan 269
Bronchiolitis
Blockage of small airways in lungs due to infection. Affects children <2. Sx: wheezing, fever, cough, runny nose, breathing problems Tx: supportive care
RSV
Most common cause of pneumonia and bronchiolitis (wheezing) in infants. Infections commonly occur in winter Causes otitis media in older children Hand washing/gloves presents nosocomial outbreaks in nurseries Fusion protein causes cells to fuse, producing multinucleated giant cells. Rapid diagnosis by detection of antigen in nasopharyngeal wash. PCR also useful for dx Passive immunization (high risk children): Palivizumab (monoclonal ab) reduces hospitalization rates between Nov and April Rx = ribavirin (FA p 161, 163)
Paramyxoviruses
Paramyxovirus (enveloped, SS, (-) linear, nonsegmented helical capsid). Parainfluenza - croup RSV - bronchiolitis in babies Measles Mumps All contain surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells. Palivizumab (monoclonal ab against F protein) prevents pneumonia caused by RSV infection in premature infants. (FA p 161, 163)
Turner syndrome: genetic basis and clinical features
Genetic basis: Complete of partial loss of an X chromosome (45, X). - Most common sex-chromosome abnormality. Clinical features: - Narrow, high-arched palate - Low hairline - Webbed neck - Broad chest with widely spaced nipples - Cubitus vagus - Short stature - Coarctation of the aorta - Bicupsid aortic v alive - Horseshoe kidney - Streak ovaries, amenorrhea, infertility
Associations of the following congenital heart abnormalities: - Atrioventricular canal defects (ASD, VSD) - Mitral valve prolapse - Tetralogy of Fallot - bicuspid aortic valve/aortic coarctation/aortic root dilatation - Patent ductus arteriosus - Truncus arteriosus - Transposition of the great arteries
AV canal defects: Down syndrome (most common congenital heart defect in Down is complete atrioventricular septal defect (CAVSD) Mitral valve prolapse: connective tissue disorders (Marfan, Ehlers-Danlos) Tetralogy - DiGeorge syndrome (chromosome 22q11.2 deletion), Down syndrome bicuspid aortic valve/aortic coarctation/aortic root dilatation - Turner syndrome Patent ductus arteriosus - congenital rubella syndrome Truncus arteriosus - DiGeorge Transposition of the great vessels - DiGeorge
VSD, ASD, PDA -Edwards syndrome
Heart defects that cause cyanosis and their presentations
Tetralogy of Fallot - cyanosis and a single second heart sound. Primary sound is harsh crescendo-decrescendo murmur caused by RV outflow tract obstruction rather than a VSD murmur. Occurs sporadically w/o other anomalies; 15% of patients with TOF have an associated condition (Eg Down or DiGeorge)
Symptomatic Ebstein anomaly. (Presents with cyanosis and heart failure due to severe tricuspid regurgitation; Auscultation reveals a “triple or quadruple gallop” [widely split S1 and S2 sounds plus a loud S3 and/or S4) and a holosystolic or early systolic murmur at the left lower sterna border)
Truncus arteriosus - neonatal cyanosis, heart failure, and systolic ejection murmur w/ loud ejection at L sternal border
Transposition of the great arteries - severe neonatal cyanosis and tachypnea
Total anomalous pulmonary venous return with obstruction - severe cyanosis, respiratory distress. Pulmonary edema, “snowman” sign (enlarged supracardiac veins and SVC)
Tricuspid atresia: Single S2, VSD murmur. X ray shows minimal pulmonary blood flow.
Necrotizing enterocolitis: Risk factors Clinical features X ray findings Treatment
Risk factors: prematurity, very low birth weight (<1.5 kg [3.3 lb]), enteral feeding (formula > breast milk) Clinical features: vital sign instability, lethargy, bilious ekes is, bloody stools, abdominal distension X-ray findings: pneumatosis intestinalis, portal venous gas, pneumoperitoneum Treatment: Bowel rest; parenteral nutrition, Broad spectrum IV abx; +/- surgery
Newborn with cyanosis aggravated by feeding and relieved by crying?
Chantal atresia. Condition may be isolated or part of a syndrome (ie CHARGE: Coloboma, Heart Defects, Atresia choanae, Retardation of growth/development, Genito-urinary anomalies, Ear abnormalities/deafness)
SIRS criteria
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Kawasaki disease (mucocutaneous lymph node syndrome)
Fever >/= 5d + >/= 4 of the following mucocutaneous findings: - conjunctivitis: b/l, nonexudative, spares the limbus - oral mucosal changes: erythema, fissured lips, “strawberry tongue” - rash -extremity changes: erythema, edema, desquamation of hands and feet - cervical lymphadenopathy: >1.5 cm node
Measles presentation
Fever Cough Coryza (rhinitis) Conjunctivitis Rash: spreads cephalocaudally
Liver pathology findings in Reye syndrome
Microvesicular fatty changes
Physiologic jaundice of the newborn: path o physiology
(See uworld question 12)
DiGeorge/velocardiofacial syndrome: pathogenesis and clinical features
Pathogenesis: Chromosome 22q11.2 deletion. Defective development of pharyngeal pouches.
Clinical features: CATCH-22: Conotruncal cardiac defects (tetralogy of Fallot, truncus arteriosus, interrupted aortic arch), Abnormal facies, Thymic hypoplasia/aplasia (T cell deficiency), Craniofacial deformities (cleft palate), Hypocalcemia/Hypoparathyroidism
VACTERL
Vertebral, Anal atresia, Cardiac, Tracheoesophageal fistula, Renal, Limb
Anomalous branches of the aortic arch: anatomy, presenting symptoms
Can cause stridor and dysphagia due to compression of trachea and esophagus.
Infantile hypertrophic pyloric stenosis: risk factors, presentation, diagnostic studies, treatment
Risk factors: first born boy, erythromycin, bottle feeding
Presentation: projectile nonbilious emesis, poor weight gain, dehydration, olive-shaped abdominal mass. “Hungry vomiter.”
Diagnostic studies: hypochloremic metabolic alkalosis, thickened pylorus on abdominal ultrasound
Tx: IV rehydration, pyloromyotomy
Presentation of milk protein-induced allertic proctocolitis (milk protein intolerance)
Vomiting, poor weight gain, bloody stools.
Treatment for long QT
Beta blockers (eg propranolol) are class II antiarrhythmics and the medication class of choice to blunt exertional heart rate and shorten the QT interval.
Symptomatic patients (lightheadedness, palpitations) or those w/ hx of syncope require a beta blocker therapy plus long-term pacemaker placement.
Fastest/most accurate method of diagnosing malrotation with midgut volvulus?
Upper GI series. The finding of the ligament of Treitz on R side of abdomen reflects malrotation while contrast in a “corkscrew” pattern indicates volvulus.
Diagnostic study to distinguish meconium ileus vs Hirschprung?
Contrast enema.
(Microcolon indicates meconium ileus; rectosigmoid transition zone indicates Hirschprung)
MEN syndromes
