Atopy is hereditary predisposition toward developing type I hypersensitivity reactions on exposure to specific antigens

1. CONSANGUINITY
ATOPY
Ms. Anitha B Vinothkumar,
Assistant Professor,
IQ City Institute of Nursing
Sciences, Durgapur, West Bengal.

2. Consanguinity
• Definition:
• Consanguinity refers to relationship by blood (being from
the same family) or by a common ancestor.

3. Consanguineous marriage
• Definition:
• It is defined as marriage between close blood relatives
who have at least one common ancestor.

4. Risks of Consanguinity
• Congenital Malformations: Eg. Anencephally, Cleft lip,
cleft palate etc.
• Phenotypic characteristics:
• Blindness, Hearing Loss, seizures

5. Risks of Consanguinity
• Metabolic Disorders:
• Phenylketonuria is three times more common than in
general population
• Other disorders: Mental Retardation, Primary
amenorrhea etc.

6. Atopy
• - The term Coined by Coca ( 1923)
Atopy is hereditary predisposition toward developing type I
hypersensitivity reactions on exposure to specific antigens.

7. Atopy includes
• Allergic Disease –Hay fever ( a Seasonal Illness –
sneezing, sniffing, running nose and itchy or watery
eyes)

8. Atopy includes
• Allergic Disease –Asthma, chronic urticaria

9. Allergy & Allergen
• Allergy is defined as abnormally high sensitivity to
antigens known as allergens.
• Allergens may be:
• Inhaled (Pollen, house dust or micro organisms)
• Ingested (egg, milk or other food)
• Contact allergens- In contact with the surface like skin or
conjunctiva

10. Allergy & Allergen
Allergens may be:
• Inhaled (Pollen, house dust or micro organisms)
• Ingested (eggs, milk or other food)
• Contact allergens- In contact with the surface like skin or
conjunctiva

11. • The antigens causing atopy (allergens) induce IgE type of
antibodies.

12. Causes
• Genetic Factors:
• It may run in families. In atopic individuals large quantities
of IgE antibodies are produced.

13. Causes
Environmental Factors: It play a role in the development of
atopy.
• Bottle-Fed: Bottle fed tends to develop atopy in later life
more often than the breast fed babies.

14. Causes
• Maternal Diet
• Maternal diet during pregnancy may be a causal factor in
atopic diseases in child, suggesting antioxidants certain
lipids, certain diet may help to prevent atopic diseases.

15. Signs & Symptoms
• Depend on Entry of antigens (Pollen) :
• Exposure to Eyes (Conjunctivitis)
• Nose (Rhinitis)
• Skin (Dermatitis)
• GI
• Common feature of allergy:
• Sneezing, Itching and skin rashes.

16. Prenatal Nutrition and Food Allergies
• Allergic diseases are common cause of illness. Diet
during early childhood is an important factor determining
the development of allergy.

17. Factors which decrease the incidence
allergy
• Maternal Diet and Atopy:
• The risk of atopy in the child can be reduced if the mother
avoids allergenic foods during pregnancy and lactation.
• Eg. For common food with allergens include milk, egg,
fish and peanuts.

18. Factors which decrease the incidence
allergy
• Infant Nutrition
• - Breast feeding and its benefit in atopy
• Exclusive Breastfeeding: Lower incidence of atopic diseases and
food allergy.
• The baby formulas contain proteins which may be allergens.
• Breastfeeding reduces frequency of GI infections
• Human breast milk contains anti inflammatory factors and
antibodies.

19. Factors which decrease the incidence
allergy
• Prolonged Breast feeding:
• If exclusive breast feeding is done beyond 4 months ,it reduces the
occurrence of allergic disease.
• It gives protection against allergy.

20. Factors which decrease the incidence
allergy
-Milk supplement:
The supplement by a hypoallergenic hydrolysate milk formula is
distinctly better than a conventional cows’ milk formula or a soya-
milk formula.
-Delayed Introduction of Allergic solid Food:
Like dairy products, eggs, fish, nuts and soya bean in the child’s diet
reduces the risk of atopy

21. Factors which decrease the incidence
allergy
- Low exposure to Environmental Agents:
Lessening exposure to dust mites, animals and tobacco smoke
reduces the risk of allergy.

22. Factors which decrease the incidence
allergy
• Identification of High Allergy Risk Newborns:
• It will help in implementing preventive measures for allergy and also
to motivate the parents to follow those measures.
• Parents with atopy: If both parents are having atopic disease, the
risk of developing allergies in the child is greater than if only one of
them is affected.

23. Factors which decrease the incidence
allergy
• IgE Level in Cord blood:
• If cord- blood immunoglobulin (Ig)E is elevated, the risk is high
irrespective of family history, conversely, low cord-blood IgE is
associated with relatively low-risk.

24. Factors which decrease the incidence
allergy
• Reduction in number of CD8 + suppressor cells
• CD8+cells play an important immunoregulatory role in IgE production.
• Reduction in CD8+ suppressor cells during the first few days of life,
increase the risk of allergy.