1. Diagnosing and Managing Common Allergies

2. Allergy Statistics (Allergy UK 2016)
615% increase in hospital admissions for anaphylaxis in 20 years, (Turner et al, JACI, 2015)
Food allergies doubled in last 10 years and hospitalisations caused by severe allergic reactions increased 7-fold (EAACI, 2015)
By 2025 asthma will represent most prevalent chronic childhood disease (EAACI, 2014)
Approx 30 allergy specialists in UK; 1 for every 700,000 sufferers

3. Allergy is a Systemic Disease
Asthma
Allergic Rhinitis
Urticaria
ALLERGY - A SYSTEMIC DISEASE
Conjunctivitis
Food Allergy
Eczema

4. What is allergy? Allergy -is a disorder of the immune system
Allergies -are inappropriate or exaggerated reactions of immune system to substances that in majority of people cause no symptoms
Atopy -tendency to develop an exaggerated IgE response - i.e. a predisposition to develop allergic disease
Allergy – the clinical expression of allergic symptoms
Self explanatory
stress the differences between these definitions
These Terms are very frequently miss used

5. Allergy mechanisms

6. Vasodilatation (redness)
Irritation of nerve endings (itching)
Increased vascular permeability (swelling)

7. Histamine causes: Urticaria (itchy, red, swollen skin)
Asthma (wheeze, cough)
Rhinitis (sneezing, blockage)
Anaphylaxis (itchy red rash, lip/tongue swelling, hypotension, wheeze etc)

8. Causes of allergy?

9. Diagnosing Allergy

10. History taking (1) Are the symptoms typical of allergy?
Is there redness, itching or swelling?
Is there an obvious allergic trigger?
Remember occupation
What is the relationship between allergen exposure and symptoms?
Typical IgE-mediated allergic symptoms occur within approximately 15 minutes of allergen exposure
Is there more than one organ system involved?
IgE-mediated allergy tends to occur in more than one organ system

11. History taking (2) Is there a past history of allergic disease?
True (IgE-mediated) food allergy more likely in adults who have seasonal or perennial hay fever or asthma or had asthma or hayfever as a baby
Is there a family history of allergy?
allergy is more common in children of (an) atopic parent(s)
Remember allergic march (eczema → food allergies → rhinitis → asthma)

12. Is there redness, itching or swelling?
Is there an obvious allergic trigger?
Do symptoms occur within approximately 15 minutes of allergen exposure?
Are there symptoms in more than one organ system ?
Is there a past history of hay fever or asthma?
Is there a family history of hay fever?
If the answer is yes to one or more questions then investigate further…..

13. …and allergy tests are unlikely to be useful
Is there redness, itching or swelling?
Is there an obvious allergic trigger?
Do symptoms occur within approximately 15 minutes of allergen exposure?
Are there symptoms in more than one organ system ?
Is there a past history of hay fever or asthma?
Is there a family history of hay fever?
If the answer is no to all the questions, then allergy is extremely unlikely….
…and allergy tests are unlikely to be useful

14. If ‘YES’ (i.e. a positive history of symptoms (itchy, red, swollen) within 15 minutes of exposure to an allergen)
Is the suspected allergic trigger avoidable or treatable with an allergen-specific treatment (avoidance or immunotherapy)?
[YES = foods, latex, bee/wasp venom, antibiotics, suxamethonium, grass pollen]
[NO = house dust mites, cats, dogs, pollens, moulds]
YES NO NO
Do you need objective confirmation?
Evidence-based avoidance
Evidence-based pharmacotherapy
YES
SPT or sIgE test to suspected allergen only
Follow up, device technique, adherence
+ve history plus +ve test
+ve history plus -ve test
Evidence-based avoidance or allergen-specific treatment
Either no action or further history-taking/ investigations

15. The Allergy March Incidence Age Allergic rhinitis Asthma
Atopic dermatitis
Incidence
Food allergy
6/12 1 3 7 15
Age

16. Examination
eyes
ears
nose
skin
height/weight
chest
general appearance

18. Triggers - Allergens House dust mites Pollens Animals Moulds
Aeroallergens
House dust mites
Pollens
Tree Pollens
Grass Pollens
Weed Pollens
Animals
Cats, Dogs, Horses etc
Moulds
Self explanatory
Aero allergens - usual triggers for atopic asthma and rhinitis
can be seasonal or perennial
Pollen calendars
Grass , tree and weed pollens all have different times of the year they are at their highest varies from different areas of the country and dependent upon the weather. Information available from met office and on web
Cat dander - it’s the protein in the cats saliva that causes the problem. As the cat washes themselves the saliva dries on their fur it then becomes airborne. Very light allergen and tends to spread Research project demonstrated high levels on jumpers of school children who did not have cats, came from friends who had cats at home.
Mould spores can trigger symptoms - Aspergillus, Clospridium, Alternaria alternate are the main ones.

21. Allergens
Penicillin

22. The Nose - a forgotten organ?

23. Natural history of Allergic Rhinitis
Onset: common in late childhood, adolescence and early adulthood
Symptoms often wane in older adults but may present or persist at any age
No apparent gender selectivity
May contribute to other disorders such as sleep disturbance, fatigue and learning problems

24. Management of Allergic Rhinitis
Allergen Avoidance
Pharmacotherapy
Immunotherapy

25. Asthma and allergies – what’s the link?
Genetics – runs in families
Rapid increase in the last 50yrs
Is the change in lifestyle to blame?
Research to see whether being exposed to allergens in early life will make someone more likely to develop asthma
EXPLAIN THAT:
Asthma often runs in families.
If one or both parents have an allergic condition such as asthma, hay fever or eczema, their child is more likely to develop asthma
However the increase over the past 50 years suggest that environmental factors must play a part
Is suggested that the increase in allergies has followed ‘Westernisation’ as countries and communities have modernised, the changes in lifestyle (diet, housing and hygiene) have lead to a increases in allergy

26. Pollen - What to do?
See GP or nurse before season starts to review asthma treatment and add on hay fever medicine
Check pollen forecast
Keep doors and windows closed mid morning/early evening – don’t take washing in at those times
Splash eyes with cold water
Wear wraparound sunglasses
EXPLAIN
measures to combat pollen

27. Pharmacotherapy Medications used to treat allergic rhinitis:
Antihistamines
Decongestants
AH-D combinations
Corticosteroids
Mast Cell stabilizers
Anticholinergics
Antileukotrienes 27

28. Actions of various nasal preparations
Sneezing
Itching
Rhinorrhoea
Congestion
Antihistamines
+++++
++++
+++
Anticholinergics
Corticosteroids
Decongestants +
Mast cell stabiliser
LTRAs
+++ ++
++++ 28

29. A form of food intolerance in which there is evidence of an abnormal immunological reaction to food
Food Allergy
Royal College of Physicians 1994

30. Adverse reactions to food
ALLERGY
INTOLERANCE
AVERSION
Immune system alteration
Pharmacological
Metabolic
Toxic
Idiosyncratic
Dislike

31. Allergic
Food Reaction
Non-allergic
Food Reaction

32. Common food triggers

33. Legumes

34. Nuts

35. Cross reactivity

36. Allergy diagnosis: tests to confirm allergic sensitivities
Specific IgE blood tests
Skin prick tests
· SPTs and specific IgE tests will be discussed in the next session
Patch tests are used in hospital settings to diagnose contact dermatitis and will not be discussed in this workshop
May be useful to mention the difference between SPT and Patch testing as people do seem to get these 2 tests confused.

37. Specific IgE Blood test which measures specific IgE
What is it?
Blood test which measures specific IgE
Sent to laboratory (local/regional)
Results not available immediately
Commonly known as RAST test (Radio allergo sorbent test)
Possible to test > 400 different allergens
Advantages – Completely safe
High degree of specificity can be as high as 90% for aeroallergens
High degree of precision and standardisation
Preferable to allergen provocation when a confirmatory test is required
results presented in absolute values or grade out of 6
Not influenced by any concurrent drug therapy
Can be performed where there is widespread skin disease
Disadvantages – Not immediate for patient to see
Results not immediately available for Health Care Practitioner
Expensive

39. Interpretation of results
A positive result AND a positive history confirms relevance of the specific trigger to that patient
A positive result on its own is meaningless (i.e. does not mean the patient will get symptoms on exposure; 80% of people who are sensitised to peanut will not get symptoms on exposure*)
Cannot be used to ‘screen’ people who have no allergy history
e.g. take a child who has not previously avoided peanuts (so exposure likely) but whose parent is concerned about allergy because a sibling is allergic. If you test for peanut, it’s positive and you advise avoidance you are condemning that child to a lifetime of avoidance without knowing if they’ll ever get symptoms on exposure….if you tell them to ignore the test result and they get a bad reaction they might sue you…….so, only test things you suspect are a problem or that people have had a reaction to!
* Nicolaou M et al J Allergy Clin Immunol 2010;125:191-7

40. Next steps If the history and the test result is positive:
either confirm diagnosis and manage in primary care
refer for specialist opinion and/or management advice
If the history and test results don’t match, or you’re not sure:
Refer to an allergy specialist

41. Think about the impact allergic disease has on children & adults
What can we do as HCP’s to improve diagnosis in children and adults?
How can we raise awareness?
How can we ensure appropriate treatment and management?

42. Time for reflection