Primary prevention

Exclusive breast-feeding (stronger effect with longer durations) and the avoidance of prenatal and postpartum environmental tobacco smoke are considered effective for the primary prevention of atopy and asthma.[8][18][82]

Reduction of exposure to multiple allergens compared with usual care has inconsistently been shown to reduce the likelihood of a current diagnosis of asthma in children, whereas single allergen avoidance measures are probably ineffective.[83][84]​​ 

Reduced exposure to traffic-related air pollution (especially levels of nitrogen dioxide [NO₂] and particulate matter 2.5 micrometers in diameter [PM2.5] or less may potentially decrease paediatric asthma incidence.[37][85]​​​​[86] 

Dietary factors

Prenatal supplementation with omega-3 PUFAs, but not fish intake, has been shown to have a marginal effect on reducing childhood asthma at doses of at least 1200 mg throughout pregnancy.[87][88][89]​​​ Vitamin D supplementation in pregnant women may also reduce the incidence of childhood wheeze and asthma.[13][90]​​​​ 

Studies of protective dietary factors, including polyunsaturated fatty acids (PUFAs), cereal and rice, dietary probiotics, and modified milk formula, have not demonstrated consistent short- or long-term benefits.[91][92][93][94]​​​ Observational studies have generally reported benefit for mediterranean diets and fish consumption, but there is a lack of evidence from randomized controlled trials.[95]​​[96]

Prevention of RSV

Not being infected with RSV during infancy was associated with a 26% lower risk of 5-year current asthma than being infected with RSV in one population-based birth cohort of healthy infants.[97] The effect on future asthma prevalence following immunization with nirsevimab (a monoclonal antibody indicated for the prevention of RSV lower respiratory tract disease in neonates and infants) may therefore be of interest.

Secondary prevention

Multimodal interventions comprising caregiver and patient education, allergen avoidance and control, and regular follow-up have been shown to reduce hospitalizations, reduce rescue corticosteroid use, and improve quality of life.[292]

Allergen avoidance

Tailored allergen mitigation strategies may be beneficial for asthma outcomes in individuals with asthma who are exposed to relevant allergens (e.g., dust mites or cat dander) and have a history of associated symptoms or positive allergy testing (e.g., skin testing or a specific IgE).[126]​ Multicomponent interventions are preferred to single-component interventions.[293][294][295][296][297][298]​​ 

Depending on the allergen in question, interventions include:[126]

  • House dust mite pesticide, air-filtration systems and air purifiers, including those with high-efficiency particulate air-filtration (HEPA) filters, and HEPA vacuum cleaners

  • Carpet removal

  • Cleaning with bleach or similar products

  • Pillow and mattress covers impermeable to dust mites

  • Integrated pest management (removing and controlling common indoor pests with traps, poison, and barriers to influx)

  • Mold mitigation (professional removal, cleaning, sanitization, demolition)

  • Pet (e.g., dogs and cats) removal or confinement to specific rooms

Allergen immunotherapy

Desensitization can be performed for common aeroallergens by either subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). However, many guidelines either do not recommend or only conditionally recommend these treatments.[1][8][100][125][126][299]​​​[300]​ Where recommended, evidence is typically only available for grass pollen and house dust mite immunotherapy in patients with mild asthma.​[299][301]

The Global Initiative for Asthma (GINA) states that allergen immunotherapy may be considered as an add-on treatment for children with established sensitization to aeroallergens, including those with allergic rhinitis, but only after asthma symptoms and exacerbations have been controlled.[1] In the 2020 US National Heart, Lung, and Blood Institute asthma guidelines, a conditional recommendation is given to use SCIT as an adjunct to standard treatment in selected patients ages 5 years and older with mild to moderate allergic asthma.[126]

Considerable variation exists worldwide in the specific SLIT and SCIT regimens used. The following recommendations have been made by GINA:[1]

  • Only offer to patients with stable disease.

  • Ensure that patients and parents are committed to long-term therapy (e.g., 3-5 years for SCIT).

  • Consider both the inconvenience and expense (both to patients and the healthcare system).

  • Ensure that patients and parents are aware of the risk of severe adverse effects (e.g., life-threatening anaphylaxis) and do not offer immunotherapy where these effects cannot be managed.

  • Tailor SCIT to the pattern of allergic sensitization.

  • Consider adding SLIT before and during the ragweed season in children with an FEV1 ≥80%.

Outdoor air pollution avoidance

Patients with well-controlled asthma usually require no adjustments when air quality is poor, but some patients may need to avoid strenuous outdoor activities or stay indoors (e.g., if concurrent viral infection or particularly high pollution levels).[1][39]​​​​

Indoor air pollution avoidance

The control of indoor air pollution, including volatile organic compounds (cleaning agents, glue, personal care products, building materials) and particulate matter (smoking, cooking, candles, insecticides, pets), is important.[60][61]

At a population level, smoke-free areas may decrease respiratory morbidity (e.g., tobacco-free cars, legislation against smoking in public areas).[302][303]​​​​ At an individual level, air purifiers or filtration systems appear to offer protection for the control of indoor allergens and pollutants (especially second-hand smoke).[304][305]

Managing obesity

Obesity is associated with an increased risk of developing asthma and asthma exacerbations.​[18][64]​[306]​​​​​ Avoiding overweight and obesity should be discussed, and where appropriate, children should be referred for weight reduction programs.[8][307]

Managing comorbid allergic rhinitis

Allergic rhinitis (AR) may coexist with asthma. A unified approach to treating the airway inflammation of both conditions is recommended.[308]

Leukotriene receptor antagonists are superior to placebo, and equivalent to antihistamines, but inferior to intranasal corticosteroids in the treatment of AR.[309][310][311]​ Intranasal corticosteroids may improve asthma symptoms and forced expiratory volume in the first second of expiration (FEV₁).[312]

Maintaining physical fitness

Patients with stable asthma should be encouraged to exercise.[313][314][315]​​​​​ Exercise (e.g., swimming) has been shown to improve cardiorespiratory fitness and quality of life without increasing respiratory symptoms, with some evidence that it might improve lung function and nocturnal symptoms in children with asthma.​[316][317][318][319]

Vaccination

Vaccination may prevent exacerbations in children with asthma.

Influenza is associated with a high healthcare burden in children with moderate-to-severe asthma. GINA recommends annual vaccination.[1][320]​​​​​[321] Reviews have shown that influenza vaccination is safe and effective for children ages ≥2 years and does not increase asthma exacerbations immediately after vaccination.[320][321][322] [ Cochrane Clinical Answers logo ] ​​​​

GINA found insufficient evidence to recommend routine pneumococcal vaccination for children with asthma.[1] Similarly, routine pertussis vaccination is not recommended.

All eligible children should receive a COVID-19 vaccination, as appropriate.[1]

Supplements

Vitamin D supplementation may decrease the incidence of respiratory tract infections and associated wheezing episodes.[18] There is insufficient evidence concerning who should receive vitamin D, the optimal levels, and how genetics (e.g., vitamin D receptor types) and/or environmental factors influence its effects.[323]

Use of this content is subject to our disclaimer