Food Allergy studies in New Zealand

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Food Allergy studies in New Zealand Associate
Professor Rohan Ameratunga
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Outline of talk

• Case history management of food allergy
• Food allergens incl cross-reactions
• Epidemiology of food allergy
• Is food allergy increasing?
• Consequences of lack of FA data in NZ
• Food allergy studies in NZ

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Case history (type 1 reaction)

• Emma aged 18 months
• Chronic eczema
• Ate peanut butter
• Within 5 minutes developed hives, angioedema and
  breathing difficulty
• Treated appropriately-recovery

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Case history (type 1 reaction)

• Diagnostic procedures
• Management plan- reduce risk of recurrence
• Is there any specific treatment?
• What is her long-term prognosis?
• How common is this problem?
• Is this problem increasing?
• What medical services are available in NZ?
• Can this problem be prevented?

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Adverse Reactions to Food

Toxic (eg. Ciguatera) Non Toxic
Immune Non Immune
(Food Allergy) (Food
Intolerance) IgE Non-IgE Enzymatic
Chemical Pharmacologic

Unknown Food Aversion
(lactase)
(histamine)
(eg eczema)
(eg celiac)
(eg.salicylate)
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Diagnostic procedures

• Short term elimination diets
• Trial of Neocate (with above)
• Food challenges
• Skin testing
• RAST testing
• Food patch testing
• Novel methods incl peptide microarrays

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RAST testing
Food cut-off sensitivity specificity Egg 6.0
U/ml 61 92 Milk 15 U/ml
51 98 Peanut 15.0 U/ml 73 92 Fish 19.5
U/ml 40 99 Wheat gt 100 U/ml PPV
60 Soy gt 100 U/ml PPV lt 50
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Food allergen avoidance/ Long-term elimination
diets

• Accurate diagnosis is critical
• Paediatric dietician assessment essential
• Reading food labels
• Manufactured Food Database
• Allergy New Zealand incl e-mail alerts

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Food allergy management plan

• Education re foods and avoidance-dietician
• Written action plan
• MEDIC-ALERT emblem-velcro
• ACC form
• Public Health nurses to visit school/daycare
• Anaphylaxis video (Allergy NZ)
• Follow up RAST testing 6-12 monthly
• Food challenge if RAST becomes negative

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Food allergens

• When food allergy is confirmed, it usually proves
  to be restricted to 1 or 2 foods
• Young children milk, egg, peanut, tree nuts,
  soy, and wheat account for about 90 of cases
• Adolescents and adults peanut, fish, shellfish,
  and tree nuts account for about 85
• Cultural variation eg rice in Japan, increasing
  sesame allergy in NZ and Australia
• Newly recognized allergens incl Anisakis, Lupin

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Treatment of food allergy

• Avoidance, avoidance avoidance
• Anti-IgE
• Peanut desensitisation
• Others incl Chinese herbs

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The prevalence of food allergy A
meta-analysis Rona et al JACI Sep 2007

• Papers selected from the literature
• Categorised according to methodology
• Cochrane methodology
• Stringent criteria for inclusion
• Divided according to age group
• Unselected population papers, not enriched
  populations such as clinic patients

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Symptoms, testing and food challenges
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Is peanut allergy increasing? Grundy et al 2002
JACI 110(5) 784-789

• Isle of Wight study
• Examined sensitisation allergy
• Significance (p0.001) (p0.2)
• 1989-1994 1.1 0.5
• 1994-1996 3.3 1

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Is food allergy increasing?

• Increase in hospital admissions for anaphylaxis
  in Australia
• Consistent methodologies needed, therefore,
  Uncertain

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The changing face of food hypersensitivity in an
Asian community Chiang et al Clin Exp Allergy 2007

• Very little data on food allergy in Asia
• Different diets
• Ethnic makeup Chinese, Indian, Malays, Eurasian
• Melting pot Rapidly changing lifestyle
• Increasing westernisation of diet
• Previous data indicates Chinese have major issues
  with fish and shellfish

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The changing face of food hypersensitivity in an
Asian community

• Study centre Kerdang Kerbau children's Hospital
  outpatient centre
• Methods prospective data on children referred
  with suspected food allergy
• Spt data collected 2003-2006
• Inclusion compatible history and spt
• Other allergies documented eczema and allergic
  rhinitis, asthma

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The changing face of food hypersensitivity in an
Asian community

• Spt positive results
• Egg 40
• Shellfish 39
• Peanuts 27
• Fish 13
• Cows milk 12
• Sesame 9
• Wheat 6
• Soy 3

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The changing face of food hypersensitivity in an
Asian community

• Food introduction
• Egg 8.6mo
• Fish 6.6mo
• Shellfish 12.2mo
• Fish introduced at the same time or earlier as
  eggs in 83 of children

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The changing epidemiology of food allergy Food
allergy studies in NZ
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Lack of food allergy data in New Zealand

• Currently no data
• May be similar to overseas??
• However ethnic makeup different
• Ethnic makeup rapidly changing
• Role of genetics
• Feeding practices may be different
• Available foods are different eg shellfish

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Food allergy studies unanswered questions

• What is the burden of food allergy?
• What services are utilised by patients
• What are the gaps in services
• What is the response of Govt agencies?
• Are there any unusual food allergies in NZ?
• What is the natural history of food allergy?
• Can food allergy be prevented?

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Agencies involved in food allergy

• Ministry of health
• ARPHS
• DHBNZ
• Ministry of Education
• PHARMAC
• MEDSAFE
• ACC
• Ministry of Trade and Industry
• FSANZ
• NZFSA
• IGA

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Lack of food allergy Research in New Zealand

• Lack of data is hindering medical services
• No paediatric allergy specialist in south Island
• Epipens unfunded

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Lack of food allergy Research in New Zealand

• Ad hoc approach in schools
• Issues with preschools

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Lack of food allergy Research in New Zealand

• Risk management issues for food industry and
  hospitality industry
• Important for food export industry
• Public not aware of the problem
• Impact on quality of life not appreciated

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Is there an ideal method to determine food
allergy prevalence?

• Large scale unselected cohort
• Regular clinical review and testing
• DBPCFC for patients with Sx or ve tests
• But...

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Is there an ideal method?

• Time dependent data
• Risk of food challenges
• Expense of studies
• No data on adults
• Change in demographics
• Change in feeding practices
• Changes in available foods
• Therefore likely to be different in others parts
  of NZ

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Difficulties with food allergy Epidemiology

• Symptoms vary according to age
• Symptoms not confined to one organ system
• Delayed reactions
• Patients may not be aware a food is triggering
  symptoms
• Survey instruments are not well established
• The need for lab tests
• Need for food challenges- expense and risks
• Studies are therefore expensive

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Difficulties with FA studies in NZ

• Funding agencies- low priority
• Food industry unaware/ denial of risk

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Advantages of working with Plunket clinics

• Up to 90 of New Zealands infants/young children
  are monitored through Plunket clinics
• Conducting our studies through Plunket is likely
  to give us a relatively unbiased sample for
  community studies of FA in NZ
• This work may increase the awareness of
  immune-mediated FA symptoms and encourage
  patients to seek medical help.

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Study 1 Pilot study of Plunket Clinics in
Auckland Interviewer assisted food allergy
questionnaire

• Clinics Manurewa, Tuakau, Sylvia Park
• Participation rate 62 (68/102)
• Total number of interviews 68
• Total number of children 96

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Pilot study of Plunket Clinics in Auckland FA
symptoms-associated with foods

• Hives
• Swelling in the skin
• Itchy skin
• Eczema (skin inflammation)
• Stomach upset (nausea, vomiting, pain)
• Mouth and or throat swelling
• Eye and nose problems (hay-fever)
• Throat tightness
• Breathing difficulties (not wheeze)
• Wheeze (asthma)
• Life threatening reaction (anaphylaxis)
• Other symptom (please list)

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Study 1 Pilot study of Plunket Clinics in
Auckland Interviewer assisted food allergy
questionnaire

• Which health professional made Dx?
• Type of testing undertaken
• Treatments given
• Demographic questions including ethnicity,
  education level etc

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Pilot study of Plunket Clinics in Auckland FA
symptoms hives
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Pilot study of Plunket Clinics in Auckland FA
symptoms eczema
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Pilot study of Plunket Clinics in
Auckland Ethnicities of participants

• study 2006 census
• NZ European 62 (60.4)
• Maori 20.8 (14.3)
• Chinese 9.4 (3.7)
• Samoan 8.3 (3.3)
• Indian 11.5 (2.7)
• Cook Island 5.2 (1.5)
• Tongan 5.2 (1.3)
• Niuean 4

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Pilot study of Plunket Clinics in
Auckland Results FA symptoms

• FA symptoms 11/96
• Males females 47
• Diagnosed by allergy specialist 3/11
• Consulted GP 8/11
• FA suspected by GP (no testing) 2/8
• Consulted GP FA not considered 6/8
• Ethnicities NZE, Maori, Indian, Chinese, Niuean

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Pilot study of Plunket Clinics in Auckland FA
symptoms Allergy specialist

• 39/12 male infant hives with baby cereal
  peanuts, milk allergy
• 36/12 female twins hives with formula milk, egg
  peanut, soy

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Pilot study of Plunket Clinics in Auckland FA
suspected by GP- not tested

• FA symptoms - not investigated 8/11
• FA suspected by GP 2/8
• 14/12 Hives with strawberry yoghurt
• 60/12 Worsening eczema after cows milk
• Advised too young to do skin tests
• Neither tested

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Pilot study of Plunket Clinics in
Auckland Consulted GP but not investigated 6/8
Age Symptoms Suspected food
4/14 eczema milk formula
7/12 vomiting wheat, milk
17/12 hives kiwifruit
4/12 vomit/aspirate milk formula
9/12 angioedema wheat, milk, egg
30/12 hives/vomiting strawberries, tomato
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Pilot study of Plunket Clinics in
Auckland Results Eczema

• Eczema 29/96 (30)
• Treated by GP 17/96 (18)
• NZ Health survey 14 with eczema
• Some mothers (4/29) changed own diet while breast
  feeding- eczema improved.
• Nutritional risks of ad hoc diets

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Pilot study of Plunket Clinics in
Auckland Results FA and family history of
allergies

• FA Sx No FA Sx
• FH allergies 55 16
• No FH allergies 45 84

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Disadvantages of working with Plunket clinics

• Parents of children gt 2yrs stop attending Plunket
  clinics
• May not attend frequently with second child
• Ethnic issues Language, transport
• Other providers eg Tamariki ora

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Pilot study of Plunket Clinics in
Auckland Limitations

• Limitations of using Plunket
• No testing was undertaken
• No food challenges were undertaken
• Small sample size
• Geographic variation
• Questionnaire needs to be validated

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Pilot study of Plunket Clinics in
Auckland Conclusions from preliminary findings

• FA probably at least as common in NZ
• Eczema is a major issue
• Under recognised
• Under investigated
• Under treated
• Affects all ethnicities
• Lactating mothers are running significant health
  risks with ad hoc diets

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Study 2 Larger cross-sectional study of FA

• Larger study of FA symptoms in Auckland
• Practical issues
• Interview room ? Mobile office
• Languages
• Cost of testing
• Food challenges
• Funding
• Value???

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Study 3 Breast feeding and FA prevention

• Currently no data on the role of elimination
  diets and breast feeding
• Mothers are given conflicting advice on early vs
  delayed introduction of allergenic foods
• Nutritional risks in ad hoc diets

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Dietary prevention recommendations (Sicherer and
Burks, 2008)
AAP 2008 Clinical Report AAP 2000 ESPACI/ESPGHAN 1999,ESPGHAN 2008 SP-EEACI 2004, 2008
High risk Parent or sibling with documented allergy Biparental or parent plus sibling Parent or sibling Parent or sibling
Pregnancy avoidance Lack of evidence Possibly peanut No special diet
Breast Feed exclusively until Evidence for 3-4 Mo (4-6 Mo tied to solids introduction) 6 Mo 4-6Mo At least 4Mo, prefer 6Mo
Maternal lactation avoidance of allergens Some evidence for reduced atopic dermatitis Peanuts, tree nuts (consider egg, milk, fish perhaps other foods) No special diet
advice that is the same as for not high risk advice that is the same as for not high risk advice that is the same as for not high risk advice that is the same as for not high risk advice that is the same as for not high risk
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Study 3 Breast feeding and FA prevention
Aim To determine whether dietary exposure (the
mothers dietary intake while breastfeeding,
formula feeding and the introduction of solids)
influences allergen sensitisation in infants at
high risk of FA up to one year
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Study Phases

• Phase 1
• Pretest food frequency questionnaire (FFQ) with
  mothers of high risk FA children
• Pretest FFQ with FA dietitians
• Seek feedback on proposed methodology
• Phase 2
• Validate FFQ (frequency of maternal intake of
  allergen containing foods) by
• Compare dietary intake with food sensitivity in
  infant
• Responses in FA questionnaire
• Validate FA questionnaire

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Study Phases

• Phase 3
• Pilot study over 1 year
• Ability to recruit subjects
• Advice given
• Testing compliance
• Power calculations
• Phase 4
• Main study over 5 years.

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Study 3 Breast feeding and FA prevention
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Study 3 Breast feeding and FA prevention
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Study 3 Breast feeding and FA prevention
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Study 3 Breast feeding and FA prevention
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Study 3 Breast feeding and FA prevention Eligibili
ty

• Have an older child with proven FA
• Pregnant- 34/40
• Regular FA questionnaire
• Regular dietary assessment
• RAST testing cord blood and 5 and 12 months
• Prelude to a longer cohort study

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Funding unrestricted grants

• Nutricia
• ADHB Charitable trust
• Allergy New Zealand
• ASCIA
• Australian Laboratory Sciences
• William and Lois Manchester trust

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Food Allergy Research Group

• Christine Crooks (LabPlus)
• Maia Brewerton (Wellington Hospital)
• Steve Buetow (UoA)
• Penny Jorgensen (Allergy New Zealand)
• Elizabeth Robinson (UoA)
• Shannon Brothers (Starship)
• Clare Wall (UoA)
• Allen Liang Allergy Specialist
• Rohan Ameratunga (LabPlus, Chair)

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Paediatric food allergy/ eczema clinic JHU

Prof Robert Wood Prof Hugh Sampson Prof Ken
Schurberth