20 Dec 2023
1. A thorough history remains the cornerstone of a reliable
allergy diagnosis.Although it usually takes more time to obtain a comprehensive allergy
history than the general patient history, it is time well invested which becomes
steadily more valuable as the examiner gains experience.
2. Asthma: extrinsic which is usually
seasonal, intrinsic which is frequently perennial.
3. & 4. Hay Fever and seasonal allergic rhinitis usually
occur in the spring and early summer and are associated with intense itching of the nose,
eyes, palate, ears and back of throat, continuous sneezing and a profuse watery nasal
discharge. Perennial allergic rhinitis is the more chronic form of nasal allergy
and symptoms occur throughout the year. The above conditions must be differentitaed from
other illness causing a blocked nose, e.g. recurrent colds, sinusitis, enlarged adenoids
and nasal septal deformities.
5. Eczema: often due to contact allergens (e.g.
animals, occupational substances – see 22) and ingestants (e.g. food).
6. Urticaria: common causes include food (often
milk, eggs, nuts, berries, shellfish, fish; less often chocolate, peas, pork, tomatoes,
maize, food colourants and preservatives), drugs (penicillin, sulpha, aspirin,
codeine), infections (bacterial, e.g. tonsilitis, viral, fungal and parasitic), inhalants
(pollen, dust, animal epithelia/dander, aerosols, hair sprays), physical agents
(cold, heat, light, vibratory), psychological (tension and anxiety do not cause
hives, but aggravate chronic hives) and most often idiopathic.
7. Headache: due to histamine release during the
allergic reaction, or secondary to sinus involvement.
8. First onset: in very young infants ingestant
allergens may be responsible for allergies (involving mainly the skin and GIT), but as the
child develops (2 or 3 years of age), inhalants usually replace the ingestants (affecting
more the upper and lower respiratory tracts). Before the age of 2-3 years, the diet is
also normally restricted to only a small range of potentially allergenic foods. Adults
onset – symptoms are more often non-allergic in origin.
9. Seasonal onset: late spring and summer – think
grass and tree pollen. Late summer and autumn – think weed pollen and mould spores. All
year round – think house-dust, animal epithelia/dander, mould spores and irritants.
10. Daily onset: If symptoms occur mainly during the
night, think of house-dust mite and feathers. if mainly during the day, think of pollen.
pollen is released in large quantities on warm and sunny mornings and as the air heats up,
it is carried high into the atmosphere during the middle of the day and descends again
during the afternoon as the air cools. The highest pollen counts thus occur in the
mid-morning and late afternoon. Cities stay hotter for longer, so the pollen count often
stays high well into the evening.
11. High humidity: both house-dust mite and mulds
thrive in warm, humid areas and are found on decaying vegetation, in shower cubicles,
basements, air-conditioners, humidifiers, dried flowers and potted indoor plants, aquaria
and refrigerator drip trays.
12. Weather changes: heavy rain usually results in a
fall in the pollen count. Windy conditions not only facilitate pollen and mould spore
distribution, but also spread of irritants and pollutants in the atmosphere. A good rainy
season is usually followed by high concentrations of grass pollen. Sudden weather changes
may trigger allergic reactions. See also 10.
13. Heat: see 10 & 11.
14. Pollution: irritants such as tobacco and industrial
smoke, exhaust fumes, perfumes, cosmetics and dust may trigger allergic reactions. There
is mounting evidence that cigarette smoke not only aggravates established allergic disease
by acting as a trigger but it also has the ability to encourage the development of
allergic disease by actually stimulating the production of the allergic IgE antibody. The
most important preventative step the pregnant mother can take is to avoid inhaling
cigarette smoke. This also means avoidance of other people’s cigarette smoke (so-called
passive smoking). Exposure of the foetus to the affects of cigarette smoke by the pregnant
mother causes increased levels of the allergenic antibody IgE in the cord blood of the
newborn, and an increased risk of allergy in infancy and childhood.
15. House dust: see also 11. House dust consists of a
variety of particles, small enough to be inhaled; such as human and animal epithelia
(dandruff), natural and synthetic fibre particles (from furniture, bedding, clothes),
innocent bacteria, insect particles, fungal spores and most important house-dust mites.
The mites are found world-wide, except in extremely dry and hot climates. It is not the
intact mites, but their droppings, eggs and dead mite particles that cause sensitisation
when inhaled. They feed on dead human and animal skin cells and are abundant especially in
bedding, mattresses, feather pillows, carpets, stuffed toys and old books.
16. Coast: see 11.
17. Indoors: see 11 7 15. If symptoms are, in general,
worse outdoors – think house-dust mite. If symptoms are, in general, worse outdoors –
think pollen.
18. Family history of allergies: an unborn child
without a family history of allergy has an approximately 12% chance of developing one or
more allergic symptoms during his/her life. If one parent has an allergic problem, the
infant’s risk increases to approximately 20%, with both parents allergic, it is greater
than 40% and when both parents have the same allergic symptoms (e.g. both have asthma),
the unborn baby has a greater than 70% chance of developing the same allergy.
19. Area: town/city – think house-dust mite, moulds and
pollution; country – think pollen, moulds and farming stock.
20. Age of home: old houses are more prone to be damp,
harbouring moulds (mildew) and mites.
21. Pillows and bedcovers (type): see also 15. Feathers
are used to stuff pillows, eiderdowns and duvets. During the night, many hours are spent
with the nose close to these feathers which also disintegrate with time into light
feather-dust which spreads easily through the whole house via air currents. Foam rubber
and other synthetic fibres can be used as a substitute for feathers.
22. Occupation and Hobbies: not only inhalants, but
especially contactants may be associated with hobbies and/or occupations. regarding
hobbies, enquire as to the use of paints, solvents and synthetic glues (especially epoxy
glues). Occupational exposure often includes formaldehyde, solvents, nickel, epoxy and
other glues, cement, oils and grease and rubber products, including latex (e.g. gloves).
Other common sources of contactants are cosmetics, topical drugs, plants and metals.
23. Patients suffering from allergy often have a dark
discoloration of the lower eyelids, called “allergic shiners“. This is
due to chronic nasal congestion which produces venous stasis in the orbit.
24. Dennes lines are semi-horizontal crescentric
creases in the lower eyelid skin, caused by persistent spasm of the unstriated muscle of
Muller in the eyelid, caused by venous stasis.
25. Because of itching of the allergic nose, it is often
rubbed in a particular way (with the palm of the hand in an upward manner) called the
“Allergic salute“. When carried on at close intervals, this manoeuvre
produces, after approximately 2 years, a permanent line in the skin above the nasal tip,
the “Allergic Nasal Crease“.
26. Long face syndrome (“Adenoid facies”):
chronic nasal obstruction during the period of active growth leads to mouthbreathing
which, in association with altered tongue function, gives rise to the now commonly termed
:Long face syndrome”. This syndrome is characterised by inter alia increase in
vertical height of the lower third of the face, narrow alar bases, lip incompetence,
narrow high arched palate, protrusion of the upper incisors, flattened molar eminences and
shortened mandible.
27. Other: e.g. facial grimacing for relief of nasal
itching when deprived of the allergic salute.
28. Systemic physical examination: note only positive
findings related directly or indirectly to allergy.
29. Blood tests for allergy: this diagram is fully
described under “Flow Diagram”, (Appendix I(a)). The blank rectangles are to be used for
dates when the test was requested, thus providing a chronological ‘allergic route’ for the
special patient’s special investigations.
30. Skin prick test (SPT): see Appendix IX.
31. Nasal smear: for eosinophils, which predominate
during the symptomatic allergic periods, See Appendix XII.