How to manage food allergy. Dr Andrew Clark Consultant in Paediatric Allergy Addenbrooke's Hospital

Transcription

1 How to manage food allergy Dr Andrew Clark Consultant in Paediatric Allergy Addenbrooke's Hospital

2 Food allergy in children and young people Implementing NICE guidance February 2011 NICE clinical guideline 116

3 Food allergies Straightforward approach to diagnosis of immediate and delayed type food allergy New presentations of food allergy

4 Epidemiology Common: 8% of children; 2-3% adults But 25 40% of adults think they are allergic Cornerstone: ruling it in and ruling it out

5 Assessment and allergyfocused clinical history (1) The Skin IgE- mediated Pruritus Erythema Acute urticaria Non-IgE-mediated Pruritus Erythema Atopic eczema Acute angioedema

6 Assessment and allergyfocused clinical history (2) The gastrointestinal system IgE- mediated Angioedema of the lips, tongue and palate Oral pruritus Nausea Colicky abdominal pain Vomiting Diarrhoea Non-IgE-mediated Loose or frequent stools Gastro-oesophageal reflux disease Abdominal pain Infantile colic Food refusal or aversion Constipation Perianal redness Pallor and tiredness Faltering growth in conjunction with at least one or more gastrointestinal symptoms above

7 BSACI guidelines for the management of Egg Allergy Andrew Clark Isabel Skypala Susan Leech Pamela Ewan Pierre Dugué Nicole Brathwaite Pia Huber Shuaib Nasser CEA 2010; 40:1116, CEA 2011; 41: 706

8 Diagnosis of IgE-mediated food allergy (2) Take an allergy-focused clinical history Tests should only be undertaken by healthcare professionals with the appropriate competencies to select, perform and interpret them. Do not use atopy patch testing or oral food challenges in primary care or community settings.

9 Clinical case 8 month girl Mild eczema Presents to primary care 2 spoonfuls of scrambled eggs Urticaria on face and chest No respiratory symptoms Resolved with oral AHs CEA 2010; 40:1116, CEA 2011; 41: 706

10 1. do you? 1. Refer to an allergy clinic? 2. Tell to try egg again to make sure? 3. Perform an egg-specific IgE test? 4. Advise to avoid egg? CEA 2010; 40:1116, CEA 2011; 41: 706

11 Diagnosis History Type of egg Hx of Eczema / asthma % Angioedema / urticaria 80-90% Abdominal pain / vomiting 10-44% Severe features <5% Wheeze, voice change, stridor, DIB Floppy / collapse CEA 2010; 40:1116, CEA 2011; 41: 706

12 IgE food allergy - rule it in Genuine type-1 hypersensitivity reactions to food are easy to spot with a few clues: History of eczema, asthma, rhinitis Rapid onset: within 1 hour of ingestion Local mucosal symptoms (itching in mouth etc) Rapid resolution (<6 hours) Urticaria/angioedema/wheeze/laryngeal oedema Recognised allergen (e.g. peanut, egg, milk) Usually obvious within 1-2 episodes

13 Rule it out - urticaria Comes to see you after episodes No consistent precipitant Reactions without precipitant Unusual precipitant e.g. food colourings Long interval before apparent reaction e.g. the next day Long duration of apparent reaction e.g. more than 6 hours More likely to be chronic urticaria

14 Diagnosis of IgE-mediated food allergy (1) If IgE-mediated food allergy is suspected, offer a skin prick test and/or blood tests Skin prick tests should only be undertaken where there are facilities to deal with an anaphylactic reaction.

15 Serum specific IgE CEA 2010; 40:1116, CEA 2011; 41: 706

16 Providing information and support (2) Provide information to parents of babies or young children with suspected allergy to cows milk protein Anaphylaxis Campaign Offer information about the support available and details of how to contact support groups

17 Clin Exp Allergy 2010; 40:1116, CEA 2011; 41: 706

18 Egg allergy Management? Egg avoidance advice Initially avoid all egg from raw to well-cooked PIS available in BSACI guideline CEA 2010; 40:1116, CEA 2011; 41: 706

19 Emergency medication Majority mild allergy - oral antihistamines IM adrenaline AI for severe symptoms or asthma Referral CEA 2010; 40:1116, CEA 2011; 41: 706

20 Milk allergy More complex presentation Common Delayed and immediate (IgE) types Think of delayed type in infants who Have Colick and reflux Eczema

21 Diagnosis of non- IgE-mediated food allergy If non-ige-mediated food allergy is suspected: trial elimination of the suspected allergen and reintroduce after the trial: 6/52 [seek advice from a registered dietician with appropriate competencies]

22 Non-IgE mediated food allergy Intolerance Delayed reactions: hrs to days Typical scenarios Colicky, vomity, eczematous infant (milk) Most common intolerance picture CM replacement with hypoallergenic formula 60-80% improvement in symptoms Manage expectations regarding allergy

23 Non-IgE mediated food allergy Typical scenarios 2-5yr old with difficult eczema Parents don t want to use corticosteroids Drinking cow s milk since birth 6 weeks CM elimination No better Concentrate on medical Rx

24 Non-IgE mediated food allergy Typical scenarios 5yr old with nocturnal cough + snoring Never wheezes Salbutamol ineffective 6 weeks CM elimination No improvement Oral antihistamines for post nasal drip

25 Non-IgE mediated food allergy Typical scenarios 6 yr old girl with recurrent abdominal pain and bloating Coeliac s negative 6 weeks cow s milk elimination 6 weeks wheat elimination Improvement?why

26 Management of CMPA Food avoidance advice for breast feeding mothers Hypoallergenic formulae Access to dietician

27 Hypoallergenic formulae Partially hydrolysed Nutramigen Aptamil Pepti Soya Phyto-oestrogens (not for boys<6m) Solids Rice Arsenic Goat / sheep etc

28 Egg and milk allergy Management? Reassure as most resolve spontaneously Re-introduction advice When to reintroduce? What sort of egg / milk? How well cooked? CEA 2010; 40:1116, CEA 2011; 41: 706

29 Timing of resolution Proportion with egg allergy % resolution Raw egg Baked egg Age (months)

30 Reintroduction Cooked egg / milk first: cake Look for accidents in the history If tolerates cake already then continue Previous mild allergy, no asthma 2-3 yrs introduce well cooked allergen??when to introduce less-well cooked?? referral

31 Food allergy referral I Faltering growth + gastrointestinal symptoms not responded to a single-allergen elimination diet One or more acute systemic reactions One or more severe delayed reactions IgE-mediated food allergy and concurrent asthma Significant atopic eczema where food allergies are suspected by the parent or carer

32 Food allergy referral II Persisting parental suspicion of food allergy Strong clinical suspicion of IgE-mediated food allergy but allergy test results are negative Clinical suspicion of multiple food allergies

33 Referral to allergy clinic Children with previous egg allergy symptoms that affected breathing (cough, wheeze or swelling of the throat, e.g. choking), the gut (severe vomiting or diarrhoea), or the circulation (faintness, floppiness or shock), Children who also receive regular asthma preventative treatment and/or have poorly controlled asthma Where diagnosis is not clear and needs to be confirmed or excluded Severe eczema in children on an egg-containing diet Persistent or adult-onset egg allergy Egg allergy with requirement for influenza or yellow fever immunisation Egg allergy with another major food allergy

34 MMR and egg allergy Appropriate to give in primary care to all children with egg allergy, regardless of previous egg reaction severity Please refer: Children who have had anaphylaxis to the actual vaccine before CEA 2010; 40:1116, CEA 2011; 41: 706

35 Influenza vaccine CEA 2010; 40:1116, CEA 2011; 41: 706

36 Clinical case 3 year old boy 6m old, urticaria after scrambled eggs Tolerates cooked egg but mouth itching with mayonnaise Asthma, well controlled on low-dose ICS Presents for influenza vaccine? CEA 2010; 40:1116, CEA 2011; 41: 706

37 Clinical case 20 year old male Persistent egg allergy since childhood Frequent reactions to contamination: lip angioedema and wheeze Asthma; stage 4 BTS Rx CEA 2010; 40:1116, CEA 2011; 41: 706

38 Influenza vaccination Indications >6m age asthma treated with continuous or repeated use of inhaled or systemic corticosteroids or with previous exacerbations requiring hospital admission Contra-indications Previous anaphylaxis to vaccine CEA 2010; 40:1116, CEA 2011; 41: 706

39 Is vaccination indicated? Influenza vaccination in eggallergic individuals No Yes Anaphylaxis to egg? Yes No Vaccinate in Hospital Asthma SIGN 4? Yes No Vaccinate in Hospital Vaccinate in primary care

40 Influenza vaccines for the 2011/12 season Product Pharmaceutical Company Ovalbumin content (per dose) Grown in FluarixGSK GlaxoSmith Kline < 0.05 µg chick embryos Intanza 9 µg Sanofi Pasteur MSD Intanza 15 µg Sanofi Pasteur MSD Split Virion BP Viroflu / Inflexal V Age Indication 6m < µg hens' eggs 18-59yr < µg hens' eggs 60yr Sanofi Pasteur < µg chick embryos Crucell UK Ltd < 0.05 µg chick embryos 6m 6m Egg-free vaccine (Preflucel ; >18y only) withdrawn Pia Huber CEA 2010; 40:1116, CEA 2011; 41: 706

41 New patterns of reaction

42 New patterns of reaction 22 year old man Allergic rhinitis in the spring Recent onset of lip swelling and mouth itching when eating raw apples, pears and cherries Hazelnuts also make his mouth itch Positive IgE tests to fruit, tree pollen and nuts

43 Pollen fruit syndrome (oral allergy syndrome) Primary disease is allergy to birch pollen protein (Bet v 1) Cross-reacting to homologous protein in fruit and nuts (Mal d 1 - apple) Generally mild reactions, even to nuts Fruit tolerated if heated Pollen Apple

44 New patterns of reaction 31 year old female History of eczema Ate small amount of kiwi fruit Severe burning sensation in mouth Throat tightening Wheeze Rx with IM adrenaline in ED

45 Lipid transfer protein (LTP) allergy Severe reactions to fruits due to LTP reactivity Heating fruit does not reduce allergenicity Also peach Pru p 3

46 Clinical Case 24 year old female Reaction in nightclub, shortly after starting to dance Generalised urticaria, lip angioedema and wheeze Normally eats at 8pm and goes to club at 12pm, on this occasion pasta at 10pm Eats wheat on other occasions without reacting

47 Food Dependent Exercise Induced Anaphylaxis (FDEIA) Commonly wheat protein is the trigger Omega-5-gliadin IgE positive Patients tolerate ingestion unless exercise within 4hrs Anaphylaxis Advise to increase gap before exercise

48 Clinical Case 68 year old male Recent onset of swelling of tongue and lower lip in evening, usually after eating Swelling subsides within a few hours Past history Hypertension

49 ACE inhibitor induced angioedema Associated with ACEIs Can begin years after first prescription Fatalities Treatment Stop ACEI and provide alternative Risk continues for several months after stopping ACEI

50 Summary Allergy-focused history usually determines diagnosis Allergy testing Vaccination Referral New presentations Secretary Caron Nolan fax