World Allergy Organization Guidelines for Prevention of Allergy and Allergic Asthma

1. World Allergy Organization Guidelines for Prevention of Allergy and Allergic Asthma Editors S.G.O. Johansson Tari Haahtela WAO Project Co-ordinator Karen Henley Davies Prevention of Allergy and Allergic Asthma. World Allergy Organisation Project Report and Guidelines. Eds. SGO Johansson and T Haahtela. Chemical Immunology and Allergy. Editors J Ring et al. Vol. 84, Karger, Basel, 2005.

2. Prevention, Definitions • Primary Prevention: prevention of immunological sensitization (i.e. development of IgE antibodies) • Secondary Prevention: preventing development of an allergic disease following sensitization • Tertiary Prevention: treatment of allergic diseases and asthma • Measures should benefit all, not harm anyone, not involve unreasonable costs

3. PAAA Contributors Innes Asher, New Zealand Tadd Clayton, New Zealand Marek L. Kowalski, Poland Alexander Chuchalin, Russia Joaquin Sastre, Spain Matthias Haus, South Africa Pakit Vichyanond, Thailand Elif Dagli, Turkey Adnan Custovic, UK Stephen T. Holgate, UK John W. Holloway, UK Katherine Venables, UK John Warner, UK Allen Kaplan, USA Richard Lockey, USA Kewin Weiss, USA Carlos Baena Cagnani, Argentina Patrick Holt, Australia Charles Naspitz, Brazil Nan-Shan Zhong, China Arne Høst, Denmark Johannes Ring, Germany Torsten Schäfer, Germany Ulrich Wahn, Germany Michal Hemmo-Lotem, Israel Benjamin Volovitz, Israel Attilio Boner, Italy G. Walter Canonica, Italy Yoji Iikura, Japan Joseph Odhiambo, Kenya

4. GeneticsCurrent knowledge • The atopic constitution is a major risk factor for the development of IgE-sensitization • Individuals with a family history of atopy have an increased risk of developing allergic diseases • Target organ sensitivity is a familial trait

5. Environmental Influences on Asthma and Allergy - Current knowledge • Cigarette smoking in pregnancy increases the risk of wheezing in infancy • Environmental Tobacco Smoke aggravates asthma • Allergen avoidance is partially successful (high risk infants) • Some early respiratory infections, e.g. pertussis and RSV, may enhance IgE-sensitization • Relative lack of early microbial exposure may enhance the development of allergic diseases

6. Early Immunological InfluencesCurrent knowledge • Allergen specific T-helper cell programming is initiated early in life and is driven by ubiquitos dietary and inhalant allergens • Early exposure to high levels of dietary allergens results in high zone tolerance • Exposure to low levels of inhalant allergens triggers low zone tolerance with weak Th1-like immunity or Th2 polarised response

7. Predictive and Early DiagnosisCurrent knowledge • Double heredity means a four-fold risk to develop allergies • Single heredity means a two-fold risk • Early signs of atopic eczema, and presence of IgE antibodies to inhalant allergens, are important risk factors for later respiratory allergy • High IgE level in cord blood is specific for subsequent allergic disease but has a low sensitivity

8. Preventive MeasuresGuidelines Primary prevention • Avoid smoking and Environmental Tobacco Smoke, particularly during pregnancy and early childhood (B). Remove tobacco smoke from work places (B) • Avoid damp housing conditions (C) and reduce indoor air pollutants (C) • Breast-feed exclusively until 4-6 months (B*). No special diet for lactating mothers (A) • Reduce exposure to inhalant allergens in young children at high risk • Eliminate sensitizing and highly irritating agents in occupational environments (C). Implement measures to prevent employee exposure * WHO: exclusive breast-feeding for 6 months in general

9. Preventive MeasuresGuidelines Secondary prevention • Treat atopic eczema topically, and possibly with systemic pharmacotherapy to prevent respiratory allergy (D) • Treat upper airways disease (rhinoconjunctivitis, sinusitis) to reduce risk of asthma (D) • In young children sensitized to mites, pets or cockroaches, exposure should be reduced to prevent onset of allergic disease (B) • Remove employees from occupational exposure if they have symptoms caused by occupational allergic sensitization (C)

10. Preventive MeasuresGuidelines Tertiary prevention • Infants with cow’s milk allergy avoid cow’s milk proteins; if a supplement is needed, use hypoallergenic formula, if available/affordable, to improve symptom control (B) • Patients with asthma, rhinoconjunctivitis or eczema, who are allergic to indoor allergens, should eliminate or reduce the exposure to improve symptom control and prevent exacerbations (A-B) • Aim pharmacotherapy primarily towards the underlying inflammatory process (A) • Avoid strictly ASA and other non-steroidal anti-inflammatory drugs (NSAID) in patients who are sensitive to them (C)

11. Preventive MeasuresFurther actions for occupational allergies • Risks of occupational allergy should be monitored and epidemiological information collected by a globally agreed questionnaire • High risk allergy environments should be identified. In atopic employees who work in these environments, detection of sensitization by Skin Prick/Puncture Tests or IgE antibody measurements could prevent development of clinical allergy • General principles of prevention of occupational allergies should be published by national regulatory and advisory authorities

12. Allergy and Asthma EducationGuidelines • Patient education regarding precipitants of allergic symptoms, asthma and anaphylaxis is essential. Guided self-management is the key to optimizing disease control (A) • School policies on asthma and anaphylaxis management are essential (D)

13. Allergy and Asthma EducationFurther actions required Initiation of an International Coalition for Allergy and Asthma Prevention. The aims are: • To collect effective programs in a database for all countries • To establish an annual convention on allergy and asthma prevention, education and applied research • To establish an International Allergy and Asthma Prevention & Education Promotion Fund

14. The Costs of Allergy and AsthmaGuideline Cost of treating allergies and asthma are increasing, switching from hospital costs to medication costs in developed countries • When considering any intervention, take into account not only the evidence showing beneficial effect but also the costs • Use the most cost-effective product or measure

15. Patient Information (Appendix 1)Allergens • House dust mite allergen reduction (major strategies, additional strategies) • Pollen avoidance • Pet allergen avoidance • Cockroach allergen avoidance • Mould allergen avoidance (indoors, outdoors) • Severe reactions, allergic anaphylaxis (schools, work places)

16. Educational Programs (Appendix 2) • Allergic asthma and rhinitis • Atopic eczema/dermatitis • Severe Reactions, allergic anaphylaxis (schools, work places)

17. Preventive MeasuresGuidelines Education • Patient education regarding precipitants of asthma, allergic symptoms, and especially anaphylaxis is essential. Guided self-management to prevent, assess and treat symptoms is the key to optimizing disease control (A) • School policies on asthma and anaphylaxis management are useful (D)