DISEASES OF INFANCY AND CHILDHOOD

Question 1

What are Childhood disease?

Answer 1

Childhood disease in the perinatal period are associated with significant morbidity and mortality.

A variety of different errors can affect the process of morphogenesis

Answer 2

Malformation: primary error involving intrinsic abnormal development process such as CHD, anenceephaly.

Answer 3

Disruption: Due to secondary destruction of a normal tissue arising from extrinsic disturbance in morphogenesis i.e amniotic band.

Answer 4

Deformation : Are extrinsic disturbances in morphogenesis. Pathologic abnormal compressive forces either acting locally or generalised leading to structural changes in a developing fetus seen clubfeet (Potter sequence component)

Answer 5

Sequence- A cascade of anomalies triggered by one initiating aberation. A single localised aberation in morphogenesis set in motion secondary effect in other organs such as oligohydramnios (Potter). The classic phenotypic feature of oligohydramnios: flatten facies,hypoplastic lungs,dislocated hip,breech,amnion nodosum etc

Answer 6

Malformation syndrome- pathologically related cascade of congenital abnormalies not explained by a single ,localised initiating agent but often caused by a single aetiologic agent such as virus or specific chromosomal abnormality.

Answer 7

6.Agenesis: complete organ absence and its primordium.
7.Aplasia: developmental failure of the primordium , resulting in organ absence
8. Atresia: Is absence of an opening of a hollow visceral organ i.e trachea and intestine.

Answer 8

9. Hypoplasia: incomplete development or decreased size of an organ with decreased numbers of cells.
10. Hyperplasia: enlargement of an organ due to increased numbers of cells.
    11 Dysplasia: Disorganised arrangement of cells

Answer 9

Based on birth weight:
AGA- Appropriate for gestational age
SGA – Small for gestational age.
LGA – Large for gestational age.
Based on gestational age:
Preterm – born before 37weeks
Post term – after 42 weeks.

Question 10

What are some causes of death under 1

Answer 10

Congenital malformations, deformations, and chromosomal anomalies
Disorders related to short gestation and low birth weight
Sudden infant death syndrome (SIDS)
Newborn affected by maternal complications of pregnancy
Newborn affected by complications of placenta, cord, and membranes
Respiratory distress of newborn
Accidents (unintentional injuries)
Bacterial sepsis of newborn
Intrauterine hypoxia and birth asphyxia
Diseases of the circulatory system

Question 11

Stages of infant and childhood development

Answer 11

1. Neonatal period : 1st four week of life.
2. Infancy : 1st year of life.
3. Age 1yr to 4years
4. Age 5yrs to 14years.
   Worldwide, infant mortality varies, 2.3 death per 1000 in Singapore to 160 in Africa continent

Question 12

CAUSES OF DEATH 1-4 YEARS

Answer 12

Accidents and adverse effects
Congenital malformations, deformations, and chromosomal abnormalities
Malignant neoplasms
Homicide and legal intervention
Diseases of the heart
Influenza and pneumonia

Question 13

CONGENITAL ANOMALIES

Answer 13

Definition: A morphologic defect a child is born with.
In USA, 1 in 33 live births has a defect.
Etiology: exact cause remains unknown
The known causes are grouped into 3: genetic, environmental, and multifactorial.

Question 14

Aetiology

Question 15

Genetic causes

Question 16

ENVIRONMENTAL FACTORS include

Answer 16

These include exposure to viruses, drugs, irradiation etc.

Viruses such as HIV,enterovirus, mumps, rubella virus, cytomegalovirus, varicella-zoster virus, influenza, and herpes simplex infection.

Congenital rubella syndrome: Deafness, mental retardation, cataracts, and heart defects (persistent ductus arteriosus, pulmonary artery hypoplasia or stenosis, ventricular septal defect, tetralogy of Fallot).

Cytomegalovirus infection has more CNS effects: mental retardation, microcephaly, deafness, and hepatosplenomegaly.

Alcohol as a teratogenic agent: fetal alcohol spectrum disorders (FASDs) - microcephaly, atrial septal defect, growth retardation, short palpebral fissures, and maxillary hypoplasia

Radiation exposure – spina bifida, microcephaly, skull defects, blindness, and other deformities.

DM – CNS malformations, fetal macrosomia; cardiac anomalies, and neural tube defects.

MULTIFACTORIAL CAUSES – Inheritance of nultiple gene polymorphism.

Question 17

PATHOGENESIS: B Pathway

Answer 17

. A complex interaction of environmental teratogens and intrinsic genetic defects.
Examples of dysmorphologic effects seen include vitamin def. asso. with multiple malformations involving several organs system of eye(xerophthalmia, bitots spots, keratomalacia, blindness), lungs (squamous metaplasia, pulmonary infection),GUT (renal ad urinary stones).

Excess of vitamin A is asso. with retinoic acid embryopathy (craniofacial defects such as cleft lip and palate, CNS (headache, dizziness, vomiting , stupor), bone and joint pain with high risk of fracture,

Question 17

What are CHILDHOOD DISEASES

Answer 17

These are disease entity common in childhood.
There are many causes of respiratory distress in the newborn, and the most common is respiratory distress syndrone (RDS) or Hyaline membrane disease.
Other causes include excessive sedation of mother,fetal head injury with delivery, aspiration of blood or amniotic fluid, intrauterine hypoxia (cord round neck)

Question 18

PATHOGENESIS: A Pathway

Answer 18

Complex, poorly understood
2 pathway
A. Timing of prenatal teratogens
B. Interplay b/w env. Teratogen and intrinsic genetic defects.
A – The intrauterine development has 2 phases (embryonic and fetal period).
1. Embryonic stage – The 1st 9 weeks of life. In the early embryonic stage, injurious agent damage cells to either abort fetus or embryo recover without defect esp. 1st 3/52. B/w 3-9wk, fetus subceptible to teratogenes with peak sensitivity b/w 4/52 & 5/52.
2. fetal stages- follows organogenesis marked by growth maturation of organ. The fetal witness growth retardation and injury.