Food Allergy studies in New ZealandAssociate Professor Rohan Ameratunga
Outline of talk
• Food allergy outline
• Epidemiology of food allergy
• Consequences of lack of FA data in NZ
• Food allergy studies in NZ
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)
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
Lack of food allergy Research in New Zealand
• Lack of data is hindering medical services
• No paediatric allergy specialist in south Island
• Epipens unfunded
Lack of food allergy Research in New Zealand
• Ad hoc approach in schools
• Issues with preschools
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
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...
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
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
Difficulties with FA studies in NZ
• Funding agencies- low priority
• Food industry unaware/ denial of risk
Advantages of working with Plunket clinics
• Up to 90% of New Zealand’s 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.
Study 1: Pilot study of Plunket Clinics in AucklandInterviewer assisted food allergy questionnaire
• Clinics Manurewa, Tuakau, Sylvia Park
• Participation rate 62% (68/102)
• Total number of interviews 68
• Total number of children 96
Pilot study of Plunket Clinics in AucklandFA 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)
Study 1: Pilot study of Plunket Clinics in AucklandInterviewer assisted food allergy questionnaire
• Which health professional made Dx?
• Type of testing undertaken
• Treatments given
• Demographic questions including ethnicity, education level etc
Pilot study of Plunket Clinics in AucklandFA symptoms: hives
Pilot study of Plunket Clinics in AucklandFA symptoms: eczema
Pilot study of Plunket Clinics in AucklandEthnicities 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%
Pilot study of Plunket Clinics in AucklandResults: FA symptoms
• FA symptoms11/96
• Males: females 4:7
• 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
Pilot study of Plunket Clinics in AucklandFA 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
Pilot study of Plunket Clinics in AucklandFA 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 cow’s milk
• Advised “too young” to do skin tests
• Neither tested
Pilot study of Plunket Clinics in AucklandConsulted 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
Pilot study of Plunket Clinics in AucklandResults: 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
Pilot study of Plunket Clinics in AucklandResults: FA and family history of allergies
FA Sx No FA Sx
• FH allergies 55% 16%
• No FH allergies 45% 84%
Disadvantages of working with Plunket clinics
• Parents of children > 2yrs stop attending Plunket clinics
• May not attend frequently with second child
• Ethnic issues Language, transport
• Other providers eg Tamariki ora
Pilot study of Plunket Clinics in AucklandLimitations
• Limitations of using Plunket
• No testing was undertaken
• No food challenges were undertaken
• Small sample size
• Geographic variation
• Questionnaire needs to be validated
Pilot study of Plunket Clinics in AucklandConclusions 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
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???
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
Study protocol
pregnancy birth 6/12 1 yr
enrol RAST RAST RAST
FFQ FFQ FFQ FFQ FFQ FFQSx Sx Sx SxSx
Study 3 Breast feeding and FA preventionEligibility
• 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
Funding: unrestricted grants
• Nutricia
• ADHB Charitable trust
• Allergy New Zealand
• ASCIA
• Australian Laboratory Sciences
• William and Lois Manchester trust
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)
Paediatric food allergy/ eczema clinic JHU
Prof Robert Wood
Prof Hugh Sampson
Prof Ken Schurberth
