Diseases of Infancy and Childhood Flashcards
Time Frames for Development:
- Neonatal period =
- Infancy =
- Age 1 to 4 years =
- Age 5 to 14 years =
- Neonatal period = the first 4 weeks of life
- Infancy = the first year of life
- Age 1 to 4 years = toddler/preschool
- Age 5 to 14 years = school age
Causes of Death For Younger than 1 Year:
- CONGENITAL MALFORMATIONS, DEFORMATIONS, AND CHROMOSOMAL ANOMALIES
- DISORDERS RELATED TO SHORT GESTATION AND LOW BIRTH WEIGHT (PREMATURITY)
- SUDDEN INFANT DEATH SYNDROME (SIDS)
- Newborn affected by maternal complications of pregnancy
- Accidents (unintentional injuries)
- Newborn affected by complications of placenta, cord, and membranes
- Bacterial sepsis of newborn
- RESPIRATORY DISTRESS OF NEWBORN
- Diseases of the circulatory system
- Neonatal hemorrhage
Causes of Death For 1-4 Years:
- Accidents (unintentional injuries)
- CONGENITAL MALFORMATIONS, DEFORMATIONS, AND CHROMOSOMAL ABNORMALITIES
- Assault (homicide)
- MALIGNANT NEOPLASMS
- Diseases of the heart
Causes of Death For 5-9 Years
- Accidents (unintentional injuries)
- MALIGNANT NEOPLASMS
- CONGENITAL MALFORMATIONS, DEFORMATIONS, AND CHROMOSOMAL ABNORMALITIES
- Assault (homicide)
- INFLUENZA AND PNEUMONIA
Causes of Death For 10-14 Years
- Accidents (unintentional injuries)
- MALIGNANT NEOPLASMS
- Intentional self-harm (suicide)
- Assault (homicide)
- CONGENITAL MALFORMATIONS, DEFORMATIONS, AND CHROMOSOMAL ANOMALIES
What represents primary errors of morphogenesis?
- Examples?
Malformations
- Ex. Extra fused thumb
- Ex. Cleft pallate
- Ex. Severe central mid face defect
Result from secondary destruction of an organ or body region that was previously normal in development. (not usually heritable)
- Example?
Disruptions
- Ex. Amniotic band syndrome
Localized or generalized compression of the growing fetus by abnormal biomechanical forces. This “uterine constraint” leads eventually to a variety of structural abnormalities.
- Example?
Deformations
(maternal, fetal, placental)
- Ex. Endometrial cavity obstructed with tumors
Cascade of anomalies triggered by one initiating aberration
- Example?
Sequences
Ex. Oligohydramnios (potter sequence)
Describes the absence of an opening, usually of a hollow visceral organ, such as the trachea and intestine
Atresia
Refers to the complete absence of an organ and its associated primordium
Agenesis
Refers to the absence of an organ but one that occurs due to failure of growth of the existing primordium
Aplasia
What the 3 major categories of congenital anomalies?
- Genetic
- Environmental
- Multifactorial
Frequencies of Congenital Anomalies:
Genetic:
- Chromosomal aberrations = ?
- Mendelian inheritance = ?
- Chromosomal aberrations = 10-15%
- Mendelian inheritance = 2-10%
Frequencies of Congenital Anomalies:
Environmental:
- Maternal/Placental Infections = ?
- Maternal Disease States (Diabetes, PKU, Endocrinopathies) = ?
- Drugs and chemicals = ?
- Irradiations = ?
- Maternal/Placental Infections = 2-3%
- Maternal Disease States = 6-8%
- Drugs and chemicals = 1%
- Irradiations = 1%
Frequencies of Congenital Anomalies:
Multifactorial: ?
Multifactorial = 20-25%
Frequencies of Congenital Anomalies:
Unknown: ?
Unknown = 40-60%
2 General Principles Affecting the Pathogenesis of Congenital Anomalies
- The timing of the prenatal teratogenic insult has an important impact on the occurrence and the type of anomaly produced.
(Embryonic vs fetal) - Interplay between environmental teratogens and intrinsic genetic defects is exemplified by the fact that features of dysmorphogenesis caused by environmental insults can often be recapitulated by genetic defects in the pathways targeted by these teratogens.
Embryonic period when most congenital anomalies occur?
3rd to between the end of the 8th week
Critical embryonic period for:
- CNS = ?
- Heart = ?
- Arms = ?
- Eyes = ?
- Legs = ?
- Teeth = ?
- Palate = ?
- External genitalia = ?
- Ears = ?
- CNS = 3- end of 5 weeks
- Heart = 3-6 week
- Arms = 4-7 weeks
- Eyes = 4-8 weeks
- Legs = 4 - end of 7 weeks
- Teeth = 6 - 8 weeks
- Palate = 6- 9 weeks
- External genitalia = 7-9 weeks
- Ears = 4-9 weeks
Defined by a gestational age less than 37 weeks, is the second most common cause of neonatal mortality, behind only congenital anomalies
Prematurity
Risk factors for prematurity?
- PPROM (preterm premature rupture of membrane)
- Intrauterine infection
- Uterus/cervix/placental abnormalities
- Multiple gestation
Hazards of prematurity?
- RDS (respiratory distress syndrome/hyaline membrane disease)
- NEC (Necrotizing Enterocolitis)
- Sepsis
- Intraventricular and germinal matrix hemorrhage
Small for GESTATIONAL age (SGA) = ?
1. Etiology (cause) –> maternal, fetal, placental
- Pathogenesis (infection, chromosomal, preeclampsia)
- Morphology (structural alterations specific to pathogenesis)
- Specific clinical manifestations/functional derangements related to this and prematurity
Fetal Growth Restriction
Fetal Growth Restriction:
Fetal influences are those that intrinsically reduce growth potential of the fetus despite an adequate supply of nutrients from the mother
- Prominent among such fetal conditions = ?
- Chromosomal disorders
- Congenital anomalies
- Congenital infections
Fetal Growth Restriction:
Placental influences:
- Adequate placental growth in the preceding mid trimester is important because during the third trimester, fetal growth places heavy demands on the uteroplacental blood supply
- Uteroplacental insufficiency is an important cause of growth restriction. This insufficiency may result from ?
- Placental causes of FGR tend to result in ASYMMETRIC growth retardation of the fetus with relative sparing of the brain
- Umbilical - placental vascular anomalies
- Placental abruption
- Placenta previa
- Placental thrombosis and infarction
- Placental infection
- Or multiple gestations
Fetal Growth Restriction:
Maternal Influences:
- The most common factors associated with SGA infants are the maternal conditions that result in decreased placental blood flow
- Vascular diseases like ? and ? are often the underlying cause
- Include thrombophilias such as ?
- Inherited diseases of hyper coagulability
- Narcotic abuse, alcohol intake, heavy cigarette smoking
- Malnutrition (esp prolonged hypoglycemia)
- Preclampsia and chronic hypertension
- Acquired Antiphospholipid Antibody Syndrome
Neonatal Respiratory Distress Syndrome:
- Pathophysiology = ?
- Morphology = ?
- Clinical features = ?
• Pathophysiology
- Fundamental defect is deficiency of pulmonary surfactant. Congenital deficiency caused by mutations in SFTPB and SFTBC genes
- Treatment = glucocorticoids
• Morphology
- There is alternating atelectasis and dilation of the alveoli.
- Eosinophilic thick hyaline membranes lining the dilated alveoli
• Clinical features
- Tachypnea
- Grunting
- Peripheral cyanosis
- Retractions
- Hypoxemia
- Ground glass infiltrates (seen in lung radiology0 caused by reticulogranular densities
RDS:
- High concentration of ventilator administered oxygen for prolonged period is associated with 2 complications?
- Retrolental Fibroplasia
2. Bronchopulmonary Dysplasia
RDS:
Bronchopulmonary dysplasia (BPD) –> ? cytokines –> Arrest ? development
- Proinflammatory cytokines (TNF, IL-1B, IL-6, IL-8)
- Alveolar
RDS:
Retrolental fibroplasia (ROP) –> ?
VEGF
- phase I = hyperoxic phase where VEGF is decreased causing endothelial cell apoptosis
- phase II= VEGF levels rebound after return to relatively hypoxic room air ventilation inducing retinal vessel proliferation characteristic of lesions in the retina
Necrotizing Enterocolitis (NEC)
• Involves what organs?
- The involved segment is distended, friable, and congested, or it can be frankly gangrenous; intestinal perforation with accompanying peritonitis may be seen.
• What do you see microscopically?
- Typically involves the terminal ileum, cecum, and right colon, although any part of the small or large intestines may be involved.
- Microscopically
- mucosal or transmural coagulative necrosis
- ulceration
- bacterial colonization
- submucosal gas bubbles may be seen
What is the most common diagnostic sign occurring in 98% of patients with Necrotizing Enterocolitis?
Pneumatosis Intestinalis (gas in the intestinal wall)
NEC
- Pathogenesis = ?
- Most cases associated with = ?
- Inflammatory mediator = ?
- Probably multifactorial
- Prematurity and enteral feeding (postnatal insult like bacteria) set in motion the cascade culminating in tissue destruction
- PAF (platelet activating factor) - increased mucosal permeability and found in increased amounts in stool and serum samples
The accumulation of edema fluid in two or more fetal compartments during intrauterine growth (pleural, peritoneal, ascites, skin)
Fetal hydrops
Fetal hydrops
- Immune
- Nonimmune
-Accumulation of fluid can be variable:
~ ? = generalized (2 or more compartments)
~ ? – localized
~ Hydrops fetalis
~ Cystic hygroma
Non-immune Hydrops:
3 major etiologies
- Cardiovascular defects – structural and functional anomalies
- Chromosomal anomalies – 45, X, and trisomies 21 and 18
- Fetal anemia (not Rh or ABO) – alpha thalassemia, transplacental Parvo
B19, twin-twin transfusion
Hemolytic disease caused by blood group antigen incompatibility between mother and fetus (Rh antigens and ABO blood groups)
Immune Hydrops
Immune Hydrops
- Pathogenesis = ?
- Of the antigens included in the Rh system, only the ? antigen is a major cause of Rh incompatibility
- The incidence of maternal Rh isoimmunization has decreased since the use of ?
- The initial exposure to Rh antigen evokes the formation of IgM antibodies, that unlike IgG antibodies, do not cross the placenta. Thus, Rh disease is uncommon with the first pregnancy.
- D antigen is a major cause of Rh incompatibility
- Rhesus immune globulin (RhIg) containing anti-D antibodies
Immune Hydrops:
- Pathogenesis for ABO incompatibility = ?
- ABO hemolytic disease occurs almost exclusively in infants of group A or B who are born of group O moms.
- For unknown reasons, certain group O women possess IgG antibodies directed against group A or B antigens (or both) even without prior sensitization.
- So the firstborn MAY BE AFFECTED
Immune Hydrops:
- Consequences of excessive destruction of red cells in the neonate = ?
- Anemia
- Jaundice (causing kernicterus- CNS damage with yellow discoloration)
Nonimmune Hydrops
- Clinical features for mild and severe = ?
- Mild
- Pallor
- Hepatomegaly - Severe
- Intense jaundice
- Generalized edema
- Signs of neurologic injury
Nonimmune Hydrops
- Histo/morpholgy = ?
- Numerous islands of EXTRAMEDULLARY HEMATOPOIESIS are scattered among mature hepatocytes in the liver
Immune Hydrops
- Histo/morphology = ?
Erythroblastosis fetalis (left shift of RBC)