Clinical Allergy – An Overview Kliniese Allergie – ‘n Oorsig

1. Clinical Allergy – An OverviewKlinieseAllergie – ‘n Oorsig Prof Sharon KlingPaediatrics & Child HealthPediatrie & Kindergesondheid

2. Overview / Oorsig • What is allergy? • Examples of allergens • How does allergy present? • Approach to diagnosis of allergic disease • Principles of management of allergic disease • Wat is allergie? • Voorbeelde van allergene • Hoe presenteerallergie? • Benadering tot diagnose van allergiesesiekte • Beginsels van hantering van allergiesesiekte

3. Hypersensitivity reactionsHipersensitiwiteitsreaksies • Tipe I: Onmiddellik • Tipe II: Sitotoksies • Tipe III: Immuunkompleks • Tipe IV: Vertraag • Type I: Immediate • Type II: Cytotoxic • Type III: Immune complex • Type IV: Delayed Gell & Coombs Classification Gell & Coombs Klassifikasie

4. What is allergy? Wat is allergie? • Hipersensitiwiteitsreaksiewatdeurimmunologiesemeganismesgemedieer word • ‘n Abnormaleimmuunrespons tot ‘n stofwatniegewoonlik ‘n reaksie in die meestemenseveroorsaaknie • Hypersensitivity reaction mediated by immunological mechanisms • An abnormal immune response to a substance that does not usually cause a reaction in most people

5. Allergy / Allergie Non IgE-mediated allergy IgE-mediated allergy Allergy is a hypersensitivity reaction mediated by immunological mechanisms Allergie is ‘n hipersensitiwiteitsreaksiewatdeurimmunologiesemeganismesgemedieer word

6. Atopy Atopie • Die oorgeërfdevermoëom IgE teenliggame in respons op laedoseringsallergenetevorm, en om ‘n kliniesesindroomteveroorsaak • = Allergie + kliniesesindroom • The inherited ability to form IgE antibodies in response to low doses of allergens and to produce a clinical syndrome • = Allergy + clinical syndrome

7. The Allergic Reaction

8. Nomenclature of allergic diseases

9. Common allergensAlgemeneallergene

10. Inhalant allergens/Inhalasieallergene • House dust mite / huisstofmyt • Pollens – grass, trees, weedsStuifmeel – gras, bome, onkruid • Animal danders/Dierhare • Moulds / swamme

11. Food allergens / Voedselallergene • Milk / melk • Eggs / eiers • Wheat / graan • Soya / soja • Fish / vis • Peanuts / grond-boontjies

12. Allergen groups / Allergeengroepe

13. Urticaria Food allergy ALLERGIC DISEASE

14. Important Allergic Conditions/ BelangrikeAllergieseToestande • Asthma / Asma • Allergic rhinitis / Allergieserinitis • Eczema / Ekseem • Food allergy / Voedselallergie • Anaphylaxis / Anafilakse

15. The allergy progression

16. Risk factors / Risikofaktore

17. Diagnosis Diagnose • Geskiedenis • Ondersoek • Spesialeondersoeke • History • Examination • Special investigations

18. History Geskiedenis • Hoofklagte • Aankoms en verloop • Seisoenalevariasie • Snellerfaktore • Vorigemediesegeskiedenis • Geboorte • Voeding / dieet • Middelallergie • Familiegeskiedenis • Omgewing • Main complaint • Onset and course • Seasonal variation • Triggers • Past medical history • Birth • Feeding / Diet • Drug allergy • Family history • Environment

19. Jannie 3 years old; 3jaar oud • Geskiedenis • Herhaalde fluitbors vanaf 18 maandeoud • Fluitbors episodes 2x/maand, toebors 1-2 nagte/week • Toe neus, loperig, jeuk • Geenseisoenalevariasie • Snellers: oefening, weerverandering, verkoues • History • Recurrent wheezing from 18 months old • Wheezing episodes 2x per month, tight chest at night 1-2x/week • Blocked, runny, itchy nose • No seasonal variation • Triggers: exercise, weather change, “colds”

20. History 2 / Geskiedenis 2 • VMG • Term NSG, geenprobleme • Borsgevoed 3 weke; soja tot 18 maande • Ekseem – aankoms 2 maandeoud • PMH • FT NVD no problems • Breast fed 3 weeks; soya till 18 months • Eczema – onset 2 months of age

21. History 3 / Geskiedenis 3 • FG • Pa gesond; ma hooikoors, brongitistydenskinderjare; broerekseem as baba • Omgewing • Sigaretrook, hondekattetuis • FH • Father well; mother hay fever, bronchitis as a child; brother had eczema as a baby • Environment • Exposed to cigarette smoke, dogs, cats

22. Examination Ondersoek • Massa & lengtealbei op 10de persentiel • Allergiesevoorkoms • Vel: ekseem in velvoue • ONK: nasale turbinate geswel • RS: hiperinflasie; diffuse fluite • Wt and Ht both on10thcentile • Allergic appearance • Skin: eczema in flexures • ENT: swollen nasal turbinates • RS: hyperinflated, diffuse wheezes

23. Allergic appearance & salute Allergiesevoorkoms & saluut Chest deformity Borskasdeformiteit

24. Special investigationsSpesialeondersoeke • Bevestigallergie • Identifiseerspesifiekeallergene • Skakelanderoorsake van simptomeuit • Confirm allergy • Identify specific allergens • Exclude other causes of symptoms

25. Investigations for allergyOndersoekevirallergie • Identifikasie van spesifiekeallergeen • Velpriktoetse • Radioallergosorbenttoets (RAST) - bloed • Identification of specific allergen • Skin prick tests (SPTs) • Radioallergosorbent test (RAST) - blood

26. Skin prick tests: Gold standardVelpriktoetse: Gouestandaard • Allergeen in epidermis ingedruk • Interaksie met IgE op velmasselle • Histamien en ander mediators word vrygestel • Striem en rooiheidbinne 5-15 minute • Kan op enigeouderdomgedoen word – sensitief en spesifiek • Allergen introduced into epidermis • Interacts with IgE on dermal mast cells • Releases histamines & other mediators • Wheal and flare reaction in 5-15 minutes • Can be done at any age; very sensitive & specific

27. Skin prick testing/Velpriktoetse

28. Skin prick tests: “Gold standard” + cost effective • What precautions should be taken before performing SPTs? • Avoid antihistamines, consent, resuscitation equipment available 2. How does one interpret SPT results? • Wheal 3 mm > neg control 3. Can one perform SPTs in young children? Is there a cut-off age? • Any age; very sensitive & specific

29. Skin prick test results • ALLERGEN RESULT • Neg control 0 mm • H Dust mite 6 mm • Dog hair 3 mm • Tree mix 4 mm • Grass mix 6 mm • Pos control 6 mm Positive > 3 mm Positief > 3 mm

30. sIgE SPT vsIgE tests • High sensitivity & specificity (new tests) • No need to withhold medication • Can be done even in severe dermatitis • Need to draw blood • Wait for results • High cost SPT Immediate results available Visible to child, parents Low cost High sensitivity & specificity Withhold antihistamines Problematic in severe eczema

31. Jannie • Dx: asma, allergieserinitis, ekseem • Snellers: weer, oefening, verkoues • Allergene: huisstofmyt, bome, grass • Blootgestelaansigaretrook, troeteldiere • Dx: Asthma, allergic rhinitis, eczema • Triggers: weather, exercise, colds • Allergens: house dust mite, trees, grass • Exposed to smoke, pets

32. Principles of ManagementBeginsels van Hantering

33. Management Hantering • Identifiseerallergeen • Omgewingsbeheer • Medikasie • (Immunoterapie) • Identify allergen • Environmental control • Medication • (Immuno-therapy)

34. Environmental control

35. Avoid cigarette smokeVermysigaretrook

36. Dust Control in the Bedroom / Stofbeheer in slaapkamer 6 13 • Damp dust • Remove carpets, curtains, books, toys • Wash bedding 600C • Bedding in sun • Cover pillow, mattress • Special vacuum cleaner 5 11 Anti-allergy bedding HEPA filter vacuum cleaner

37. >9 million cats in UK Cats present in up to 70% of UK homes Most parents will not dispose of cats even if their children are allergic “Children leave home…. but pets are for life”

40. Immunotherapy (IT) – expensive!Immunoterapie (IT) – duur! • Allergieserinitis • Huisstofmyt, grasstuifmeel • Bygif • Roetes • Subkutaan • Ondertong (SLIT) • Allergic rhinitis • House dust mite, grass pollen • Bee venom • Routes • Subcutaneous • Sublingual (SLIT)

41. Sublingual Immunotherapy S Photos courtesy of Prof CasMotala

42. Jannie: MxJannie: Mx • Omgewing:sigaretrook, huisstofmyt; (gras) • Medikasie:behandelasma, rinitis, ekseem • Environment: cigarette smoke; house dust mite; (grass) • Medication: treat asthma, rhinitis, eczema