Diagnosing and Managing Common Allergies

1. Diagnosing and Managing Common Allergies

2. Allergy Statistics (Allergy UK 2016) • 615% increase in hospital admissions for anaphylaxis in 20 years, 1992-2012 (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

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. If the answer is yes to one or more questions then investigate further…..

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

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

18. Triggers - Allergens Aeroallergens • House dust mites • Pollens • Tree Pollens • Grass Pollens • Weed Pollens • Animals • Cats, Dogs, Horses etc • Moulds

21. Penicillin Allergens

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

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

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

28. Actions of various nasal preparations LTRAs +++ ++ 0 ++++

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

31. Non-allergic Food Reaction 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

37. Specific IgE What is it? • Blood test which measures specific IgE • Sent to laboratory (local/regional) • Results not available immediately

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 * 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