3. WHAT IS ALLERGY?
▶Allergy – Hypersensitivity
▶It is an specific immunologic reaction to an
imunogen,a normally harmless substance(allergen)
▶It was first defined in 1906 by Von Pirquet aho
described allrgy as changed or aaltered reation in
the body of an individual,in response to a substance
or condition that is harmless to others.
4. PREDISPOSING FACTORS WHICH MAKE THE PERSON
HYPERSENSITIVE TO ALLERGENS
Hereditary tendency to allergic response
Dysfunction of the endocrine glands
Increased excitability of sympathetic and
parasympathetic nervous systems.
Absorption of metabolic and catabolic
substances.
Hepatic dysfunction.
Psychic influences.
6. INHALANT ALLERGENS
■ Inhalant allergens are air borne substances
such as chemicals,causing respiratory
disease,inflammation in the nose and lungs
■ Inflammation in the nose is characterized by
sneezing,lacrimation,itching and swelling of nose
and eyes. The condition is known as sinuritis or
hay fever.
■ Inflammation of lungs is often expressed as
ASTHMA
7. SYMPTOMS OF ALLERGIES TO INHALANT ALLERGENS
o Sneezing often accompanied by a running nose
o Coughing and post nasal drip
o Itching eyes,nose and throat.
o Allergy shiner(dark circles under the eyes caused by increased
blood flow near the sinuses)
o The ‘ ALLERGIC SALUTE’ (in a child persistent upward rubbing
of the nose that causes mark on the nose)
o Watering eyes,conjunctivitis
8. SOME OF THE INHALANT ALLERGENS ARE
▶Pollens
▶Dust
▶Mites
▶Mold spores
▶Animal allergy(epidermis or dander)
9. POLLEN ALLERGENS
Pollens are the tiny,egg
shaped,round,angular,square,rectangular or otherwise shaped
male cells of flowering plants.
These microscopic,powdery granules are necessary for plant
fertilization.
The average pollen particle size is less than the width of an
average human hair.
Most pollen grains are single entities but some may be a
2-compound,3-compound,tetrad or so forth.
The pollens are of two types such as ANEMOPHILOUS(wind
pollinated) and ENTOMOPHILOUS(insect pollinated)
10. ANEMOPHILOUS
Anemophilous pollens are usually small 15-45
micro in diameter,light,non-adhesive and
relatively smooth and are produced by plain
looking plant e.g,Trees
(oak,walnut);grasses(bermuda grass and
timothy) and weeds(rag weed,plantain).
Most common allergic reactions are produced
by wind pollinated pollens,because of their light
weight and the dry nature,these pollen grains
are carried for long distances.
11. ENTOMOPHILOUS
Entomophilous plants are usually larger in
size(upto 200 micro in
diameter),heavier,adhesive and may be
somewhat spiny.
Plants are scented,with coloured flowers such
as clover,hollyhock,honey suckle and rose.
12. EARLY SPRING POLLINATING TREES
■ Ulmus americana (america elm)
■ Umus rubra muohlenb (slippery elm)
■ Acer saccharinum (silver maple)
■ Acer rubrum (red maple)
14. MOLD ALLERGY
Molds are an important cause of seasonal rhinitis or
non-seasonal hay fever.
Mold season peaks from july to late summer.
Unlike pollens,molds may persist after the first killing
frost,some can grom at subfreezing temperatures.
After the spring thaw,molds thrive on the vegetation that
has been killed by the winter cold in the warmest
areas,however molds can cause year-round allergic
problems.
15. MOLD ALLERGY
In addition,molds growing indoors can cause perennial allergic
rhinitis even in the cold climate.
Microscopic fungal spores or sometimes fragments of fungi
may cause allergic rhinitis because they are so small,they
may evade the protective mechanisms of the noe and upper
respiratory tract to reach the lungs.
In some people,symptoms may be brought on or worsened by
eating certain foods,such as cheeses,processed with
fungi.Occasionally,mushrooms,dried fruits and foods
containing yeast,soya,sauce,vinegar will produce allergic
symptoms.
16. HOUSE DUST AND DANDRUFF ALLERGENS
Dust is almost indefinable because it differs from one place
to the next;but commonly it composed of mold spores;cotton
linters or fragments of cotton fibrs that are light enough to
float in the air,animal danders,cat,dog,guinea
pigs,chicken,rabbit,human hair and dandruff,chicken
excreta,,odours and perfumes,etc
In house dust,common allergens are particularly the acarine
mite,dermatophagoides and specifically its species
D.pteronyssinus.
17. DUST MITE ALLERGY
Dust mite allergy is an allergy to a microscopic organism
that lives in the dust and is found in all dwellings and work
places.
Dust mite is the most common cause of perennial ALLERGIC
RHINITIS . It produces symptoms similar to pollen allergy
and can produce ASTHMA.
The dust mites appear to be distributed universally and
usually found in furnishings sniffed with vegetable fibres(e.g.
cotton)
18. INGESTANT ALLERGENS
Allergens which are present in food stuff and swallowed
are termed INGESTANT.
A food allergy is an immune system responsible to a
food.Once the immune system decides that a particular
food is harmful ,it creates specific antibody to it
The gastrointestinal symptoms are mainly effected by the
food allergens but they also causes skin rash,puffed lips
and tongue,migraine,rhinitis or other symptoms like severe
eczema of hand and feet.
19. Ingestant allergens
Some most common food allergens ingested by patients are:
▶EGG
▶MILK
▶PEANUT
▶TREENUT(WALNUT CASHEW NUT)
▶FISH
▶SHELLFISH
▶SOY
▶WHEAT
▶ORANGE JUICE
▶COD LIVER OIL
20. INGESTANT ALLERGENS
In addition to the above mentioned normal food there
are food additive,which also could be allergic to any
individual viz.mannitol,sorbitol,polysorbates,malt-dextrins,
citrus,bioflavanoids,artificial preservatives,artificial
colors,citrus pectin,talc,soy lecithin,gluten,soy flour,rice
flour,alfalfa,potato starch and gum acacia.
Milk allergy may result in severe in
dermatitis,recurrent rhinorrhoea,bronchitis and asthma
21. INJECTANT ALLERGENS
o Injectant allergens causes symptoms similar to those of the
antibiotics e.g.PENICILLIN , CEPHALOSPORIN and SEMI
SYNTHETIC PENICILLIN , etc
o Itching of the palms of the hands and the soles of the
feet,erythema and peeling of the skin are characteristic.
o In severe cases,ANAPHYLACTIC SHOCK may occur.
22. Injectant allergens
• The natural sources of injectable allergens are produced by
the sting of bees,hornets and wasps.
• The allergens injected by the stings of such insects can
induce severe local and constitutional reaction sometimes
causing death.
• In addition to penicillin products,other injectable that may
cause allergies are liver extract,antitoxins and the glandular
products.
23. CONTACTANT ALLERGENS
A number of plants and their products have been
identified as the causes of contact allergies.
The plant most responsible for contact dermatitis in
natural allergen belong to ANCARDIACEAE family.
Many plants of compositae family,which include the
ragweeds also cause contact dermatitis and the
allergens responsible had been identified as
SESQUITERPENOIDS LACTONE.
24. CONTACTANT ALLERGENS
Sesquiterpenoid lactone isolated from plants of
compositae,lauraceae and magnoliaceae and
from liverwort causes allergic contact
deramatitis in the hypersensitive individuals.
AEROALLERGENS such as the various pollen grains
containing oils,trichomes from various
leaves,flowers and small fragments of plant
tissue carried by smoke originating from brush
fires,grass fires and burning leaves are also
cause for contact dermatitis.
25. ▶A number of plant products used as additives in
cosmetics and perfumes are irritants and cause skin
allergy to some hypersensitive individuals . These type
of allergen are termed as HYPOALLERGENIC COSMETICS.
▶WOOL FAT (lanolin) in cosmetics , soap and soap powders ,
plain detergents and enzyme detergents , nail polishes ,
hair dye and hair spray are also included among the
major causes of contact dermatitis.
26. INFECTANT ALLERGENS
Allergy caused by the metabolicnproduct of living micro
organism in the human body.
The continual presence of certain types of
bacteria,protozoas,molds,helminths and other parasites in the
body of human being are responsible for chronic infection for
which patients are not aware but metabolic product of their
growth causes allergic symptoms.
The continuous presence of growth products and metabolic
waste of parasitic organism such
hookworms,pinworms,tapeworms,threadworms and
dermatophytes are referred as infectant allergens.
