GP REFRESHER 2016 Phil Wylie ALLERGY UPDATE Key pointers (plus bit extra as talked on this in 2015!) GP REFRESHER 2016 Phil Wylie

1. Only useful tests for IgE mediated allergy (with few exceptions!)

Hypersensitivity Reproducible ALLERGIC HYPERSENSITIVITY (immunologic mechanism defined or strongly suspected) NON ALLERGIC HYPERSENSITIVITY (immunologic mechanism excluded) IgE MEDIATED NOT IgE MEDIATED AUTOIMMUNE COELIAC NONATOPIC ATOPIC EOSINOPHIL e.g GASTROENTEROPATHY. IgG MEDIATED

Typical IgE symptoms (type 1 immediate hypersensitivity) Urticaria Angioedema Stridor Wheeze Diarrhoea Hypotension – pale Tryptase (within 4 hours)

“Allergy tests” are not useful for most RAST/SPT give very similar information (both IgE) Most allergy in preschool group non IgE mediated. Can switch between IgE mediated and non IgE mediated Non IgE mediated: History - ? Food diary Exclusion and challenge Be aware common cross reactants (eg milk and soya) Manage in Primary Care? Refer if suspected IgE mediated – tests useful and challenges, if appropriate, may need to be in hospital

2. What is the natural history of food allergy?

Natural history varies with allergen Prevalence Peanut, fish allergy 20% resolve Shellfish, tree nut allergy - persists Milk, egg, wheat allergy Age

When, where and how to challenge? Normalise diet as soon as possible IgE mediated – use SPT/RAST to help decide when and possibly need to take place in hospital Non IgE mediated (milk, wheat, soya, egg) – consider natural history. When not reacted for period consider challenge. Challenge at home Protein ladders – milk, egg, soya

3. What children do I need to consider CMPA in?

Non IgE mediated symptoms 2-72 hours after ingestion Gastrointestinal Colic, reflux (unhappy subgroup), loose stools, perianal redness, constipation, blood/mucus in stools in otherwise well infant Skin Pruritus, erythema, AE “Catarrhal” airway symptoms

No tests Can be managed in primary care (3% population) Exclusion and challenge (Nutramigen) Dorset wide guideline (useful flowchart) Gives dietetic advice (no need see dietician), recipes to manage dairy free diet in toddler’s, advice on normalising diet in due course etc

4. What is not allergic? Lactose intolerance Lactose is a sugar not a protein Confusion with CMPA (“lactose free” contains CMP) Different symptoms – bloating, diarrhoea Usually temporary in paediatrics post gastroenteritis 20% UK population feel they have problem with milk but most don’t have clinical evidence lactose malabsorption (milk important source calcium, vit D, iodine etc) Lactase concentration will be low after period of dairy exclusion

FODMAP Fermentable, Oligo, Di, Monosaccarides And Polyols Simple and complex sugars in variety fruit/vegetables/milk/wheat > unaltered to colonic bacteria Symptoms bloating, abdominal pain, loose stools If suspected need dietetic input if beyond exclusion few foods ? Role in toddler’s diarrhoea (sorbitol) Reactions to chemicals, E numbers etc in food Gluten sensitivity (excluding coeliac/wheat allergy) A2 milk – A2 beta casein, contains lactose. A1 beta casein incomplete digestion to form opiate BCM-7 > GI/skin/neurological symptoms

5. Who should get Epipen?

Is severity of future reaction predictable? Many factors will influence severity of reaction such as intercurrent infection, exercise, amount of allergen ingested etc etc Not going to get worse after each exposure Tests don’t help you predict severity of future reactions

Risk factors for predicting severe reactions/life threatening anaphylaxis Severity symptoms of previous exposures Severe symptoms with only minimal exposure Co-existing asthma – inhaled steroids (particularly if poorly controlled) Age especially teenagers Risk taking behaviour (low in preschool group) Remember risk death is extremely low (smaller than being killed by lightening). Please delay decision to prescribe Epipen until seen in clinic (Phil Wylie allergy clinic?)

Emergency drugs in anaphylaxis? A. Steroids, adrenaline, antihistamine B. Oxygen, adrenaline, antihistamine C. Steroids, antihistamine, adrenaline, ventolin D. Adrenaline, ventolin, oxygen E. Antihistamine, steroid, adrenaline

6. Can we prevent food allergy developing in the first instance?

Why does immune system become primed? Route Gut – usual way proteins enter! Skin – unusual – relevant when have “leaky skin” (eg eczema) Amount – tiny amounts protein sufficient (eg in dust, creams etc) (Genetics) Animal models/population studies

LEAP study – LEarning About Peanut High risk peanut allergy – AE or egg allergic Peanut avoidance vs peanut ++ from recruitment (4-11 months) EAT study (Enquiring About Tolerance) looking at cow’s milk, egg, wheat, sesame, fish, peanut (introducing at 3 months) HEAP study - egg

Applying LEAP now? Avoid eczema developing if possible Treat it aggressively in babies if it occurs (emollient +++) to try and keep skin in good condition SPT for peanut and cashew before weaning and introduce if negative (eg peanut/cashew nut butter, Bamba snacks)

7. Is recurrent acute urticaria due to food allergy? Accurate diagnosis Most burns out within a few months Role of viral infection Are tests useful? Symptomatic treatment – cetirizine can be used up to 4x dose in BNFc (? More effective if used preventative rather than as treatment after symptoms occurred)

8. What is pollen-food allergy syndrome? Hayfever 40% of hay fever sufferers who are allergic to birch or grass pollen will have this symptom Birch – apple, hazelnut, carrot, pear, tomato, celery, potato, peach Grass – melon, orange, tomato, wheat Perioral and not dangerous Disappear if food cooked REASSURANCE all that is needed

9. What is the Dorset Paediatric Vanguard Project? Patient empowerment – self management Admission avoidance “Hot phone” for advice GP<>Consultant discussions Urgent access clinic PAU with CCN outreach “Care close to home”

WE NEED YOUR VIEWS PLEASE Supporting Primary care Patch working More educational events Clinics in Primary care clinics Advice and guidance for non-urgent problems (Bridport locality pilot) WE NEED YOUR VIEWS PLEASE

10. What is Wessex Healthier Together? Wealth of information for families, health care professionals ( www.what0-18.nhs.uk ) App/android 6 pathways for common conditions Fever in children < 5 years Abdominal pain Asthma/wheeze Diarrhoea and vomiting Bronchiolitis Head injury

Any questions?