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