Asthma Management Handbook

Managing triggers in children


Advise parents/carers to ensure that children are not exposed to tobacco smoke and to ensure that the home and car are smoke-free zones. Explain that smoking outdoors near children still exposes children to smoke.

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available).

Last reviewed version 2.0

All health professionals should advise parents and household members about smoking cessation options and support them to quit smoking.

How this recommendation was developed

Adapted from existing guidance

Based on reliable clinical practice guideline(s) or position statement(s):

  • RACGP 20141

Last reviewed version 2.0

Identify aeroallergens to which the child is sensitised and reduce exposure to allergic triggers, where avoidance is feasible and has been shown to be effective and cost-effective.

Table. Summary of asthma triggers Opens in a new window Please view and print this figure separately:

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available).

Last reviewed version 2.0

More information

Back-to-school asthma care

Each year during February, a few days after the school year starts, there is an annual increase in asthma flare-ups among children with asthma. 

Asthma flare-ups in children, including those resulting in emergency department presentations and hospitalisations, surge during the first month of the school year. 234, 6 There are smaller increases at the beginning of the other school terms.7 These flare-ups may be due to changes in exposure to virus, allergens, pollution and/or stress during the early days after school return.8

Primary care health professionals can help parents/carers prepare for back-to-school flare-ups by:

  • recommending a full asthma review at the end of the school holidays to check asthma control, adherence to preventer and inhaler technique
  • ensuring that each child has an up-to-date written asthma action plan and the child and/or parents/carers understand how to follow it
  • reminding parents/carers to get their child back into their asthma routine before the school year starts, including taking preventer medications every day, if prescribed

Last reviewed version 2.0

Thunderstorm asthma

Certain types of thunderstorms in spring or early summer in regions with high grass pollen concentrations in the air can cause life-threatening allergic asthma flare-ups in individuals sensitised to rye grass, even if they have not had asthma before.9, 10, 11, 12, 13

Sensitisation to rye grass allergen is almost universal in patients who have reported flare-ups consistent with thunderstorm asthma in Australia.

People with allergic rhinitis and allergy to ryegrass pollen (i.e. most people with springtime allergic rhinitis symptoms) are at risk of thunderstorm asthma if they live in, or are travelling to, a region with seasonal high grass pollen levels – even if they have never had asthma symptoms before. This includes people with undiagnosed asthma, no previous asthma, known asthma.910 Lack of inhaled corticosteroid preventer treatment has been identified as a risk factor.9

Epidemics of thunderstorm asthma can occur when such a storm travels across a region and triggers asthma in many susceptible individuals. Epidemic thunderstorm asthma events are uncommon, but when they occur can they make a high demand on ambulance and health services.141315

Data from thunderstorm asthma epidemics suggest that the risk of asthma flare-ups being triggered by a thunderstorm is highest in adults who are sensitised to grass pollen and have seasonal allergic rhinitis (with or without known asthma).9

The worst outcomes are seen in people with poorly controlled asthma.14 Treatment with an inhaled corticosteroid asthma preventer was significantly protective in a well-conducted Australian case-control study.10

There is insufficient evidence to determine whether intranasal corticosteroids help protect against thunderstorm asthma. Intranasal corticosteroids reduce symptoms of allergic rhinitis and limited indirect evidence suggests they may protect against asthma flare-ups in people not taking inhaled corticosteroids.16

The effectiveness of specific allergen immunotherapy in protecting against thunderstorm asthma has not been evaluated in randomised clinical trials, but data from a small Australian open-label study suggest that short-term treatment with five-grass sublingual immunotherapy may have been protective in individuals.17

Last reviewed version 2.0

Asthma triggers in children: respiratory tract infections

Viral respiratory infections, such as the common cold, are a frequent cause of wheezing and asthma flare-ups in children, especially in preschool children.

The findings of observational cohort studies and limited randomised controlled trials show that influenza vaccination reduces the number, frequency and duration of asthma flare-ups in children, and lower the rate of emergency department visits and hospitalisation for asthma.18

Although bacterial respiratory infections may also trigger wheezing, antibiotics are not routinely indicated for asthma flare-ups or wheezing, and should only be given if they would otherwise be indicated.

Last reviewed version 2.0

Asthma triggers in children: environmental allergens

There is insufficient evidence on which to base recommendations for the reduction of exposure to environmental allergens in the treatment of wheezing in preschool children.19

Last reviewed version 2.0

Asthma triggers in children: tobacco smoke

There is consistent, high-quality evidence that exposure to environmental tobacco smoke can both cause and worsen wheezing in preschool children.1920

The Introduction of environmental tobacco controls has led to significant reduction in asthma hospitalisations among children.

Last reviewed version 2.0



  1. Royal Australian College of General Practitioners,. Supporting smoking cessation. A guide for health professionals. RACGP, 2014. Available from:
  2. Johnston NW, Johnston SL, Duncan JM et al. The September epidemic of asthma exacerbations in children: a search for etiology. J Allergy Clin Immunol 2005; 115: 132-8. Available from:
  3. Sears MR, Johnston NW. Understanding the September asthma epidemic. J Allergy Clin Immunol 2007; 120: 526-9. Available from:
  4. Eggo RM, Scott JG, Galvani AP, Meyers LA. Respiratory virus transmission dynamics determine timing of asthma exacerbation peaks: Evidence from a population-level model. Proc Natl Acad Sci U S A 2016; 113: 2194-9. Available from:
  5. Ahmet, A, Kim, H, Spier, S. Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy. Allergy Asthma Clin Immunol. 2011; 7: 13.
  6. Australian Institute of Health and Welfare. Asthma hospitalisations in Australia 2010-11. Australian Institute of Health and Welfare, Canberra, 2013. Available from:
  7. Australian Centre for Asthma Monitoring. Asthma in Australia 2011: with a focus chapter on chronic obstructive pulmonary disease. Asthma series no. 4. Cat. no ACM 22. Australian Institute of Health and Welfare, Canberra, 2011. Available from:
  8. Tovey ER, Rawlinson WD. A modern miasma hypothesis and back-to-school asthma exacerbations. Med Hypotheses 2011; 76: 113-6. Available from:
  9. Davies J, Queensland University of Technology. Literature review on thunderstorm asthma and its implications for public health advice. Final report. Melbourne: Victorian State Government Department of Health and Human Services; 2017. Available from:
  10. Girgis ST, Marks GB, Downs SH et al. Thunderstorm-associated asthma in an inland town in south-eastern Australia. Who is at risk? Eur Respir J 2000; 16: 3-8.
  11. Marks GB, Colquhoun JR, Girgis ST, et al. Thunderstorm outflows preceding epidemics of asthma during spring and summer. Thorax. 2001; 56: 468-71.
  12. D'Amato G, Vitale C, D'Amato M et al. Thunderstorm-related asthma: what happens and why. Clin Exp Allergy 2016; 46: 390-6.
  13. Victoria State Government Department of Health and Human Services. The November 2016 Victorian epidemic thunderstorm asthma event: an assessment of the health impacts. The Chief Health Officer’s Report, 27 April 2017. Melbourne: Victorian Government; 2017.
  14. Thien F, Beggs PJ, Csutoros D et al. The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors. Lancet Planet Health 2018; 2: e255-e63. Available from:
  15. Andrew E, Nehme Z, Bernard S et al. Stormy weather: a retrospective analysis of demand for emergency medical services during epidemic thunderstorm asthma. BMJ 2017; 359: j5636. Available from:
  16. Lohia S, Schlosser RJ, Soler ZM. Impact of intranasal corticosteroids on asthma outcomes in allergic rhinitis: a meta-analysis. Allergy. 2013; 68: 569-79. Available from:
  17. O'Hehir RE, Varese NP, Deckert K et al. Epidemic thunderstorm asthma protection with five-grass pollen tablet sublingual immunotherapy: a clinical trial. Am J Respir Crit Care Med 2018; 198: 126-8. Available from:
  18. Vasileiou, E., Sheikh, A., Butler, C., et al. Effectiveness of influenza vaccines in asthma: a systematic review and meta-analysis. Clin Infect Dis. 2017; 65: 1388-1395. Available from: [ Full text at:]( Full text at:
  19. Brand PL, Baraldi E, Bisgaard H, et al. Definition, assessment and treatment of wheezing disorders in preschool children: an evidence-based approach. Eur Respir J. 2008; 32: 1096-1110. Available from:
  20. Burke H, Leonardi-Bee J, Hashim A, et al. Prenatal and passive smoke exposure and incidence of asthma and wheeze: systematic review and meta-analysis. Pediatrics. 2012; 129: 735-744. Available from: