Primary prevention

Asthma pathway (BTS, NICE, SIGN) [SIGN 244]

This content is from the BTS/SIGN British guideline on the management of asthma (SIGN 158), 2019.

 

      

Monofaceted and multifaceted allergen avoidance

Early life exposure to allergens (including aeroallergens and ingested food allergens) may lead to allergic sensitisation and so potentially increase the risk of subsequent asthma, particularly in children at high risk (that is, children with a family history of asthma or atopy, particularly a parental history).

 

R
Measures to reduce in utero or early life exposure to single aeroallergens, such as house dust mites or pets, or single food allergens, are not recommended for the primary prevention of asthma.

[BTS/SIGN 2019]

 

R
For children at risk of developing asthma, complex, multifaceted interventions targeting multiple allergens may be considered in families able to meet the costs, demands and inconvenience of such a demanding programme.

[BTS/SIGN 2019]

Aeroallergen avoidance

House dust mites

Exposure to high levels of house dust mite allergen in early life is associated with an increased likelihood of sensitisation to house dust mite by three to seven years of age.281 Sensitisation to house dust mite is an important risk factor for the development of asthma, 282, 283 and a few studies have suggested that exposure to high levels of house dust mites early in life increases the risks of subsequent asthma.284, 285

 

R
Healthcare professionals should not recommend house dust mite aeroallergen avoidance for the primary prevention of asthma.

[BTS/SIGN 2019]

 

Pets in the home

A large number of birth cohort studies, longitudinal cohort studies and cross-sectional studies have addressed whether exposure to pets in the home in early life increases or reduces the subsequent risk of asthma and allergy, with contradictory results.

 

R
Healthcare professionals should not offer advice on pet ownership as a strategy for preventing childhood asthma.

[BTS/SIGN 2019]

Food allergen avoidance

 

R
In the absence of any evidence of benefit and given the potential for adverse effects, maternal food allergen avoidance during pregnancy and lactation is not recommended as a strategy for preventing childhood asthma.

[BTS/SIGN 2019]

Breastfeeding

 

R
Breastfeeding should be encouraged for its many benefits, including a potential protective effect in relation to early asthma.

[BTS/SIGN 2019]

Weight reduction in overweight and obese patients

There is consistent evidence that being overweight or obese increases the risk of a subsequent physician diagnosis of asthma by up to 50% in children and adults of both sexes.309, 310 A high birth weight is also associated with a higher risk of asthma.309

 

R
Weight reduction is recommended in obese patients to promote general health and to reduce subsequent respiratory symptoms consistent with asthma.

[BTS/SIGN 2019]

 

R
Obese and overweight children should be offered weight-loss programmes to reduce the likelihood of respiratory symptoms suggestive of asthma.

[BTS/SIGN 2019]

Avoidance of tobacco smoke and other air pollutants

There is an increased risk of infant wheezing associated with maternal smoking during pregnancy which adversely affects infant lung function.318-321

 

R
Current and prospective parents should be advised of the many adverse effects which smoking has on their children including increased wheezing in infancy and increased risk of persistent asthma.

[BTS/SIGN 2019]

Immunisation

 

R
All childhood immunisations should proceed normally as there is no evidence of an adverse effect on the incidence of asthma.

[BTS/SIGN 2019]

References

  1. 281. Wahn U, Lau S, Bergmann R, Kulig M, Forster J, Bergmann K, et al. Indoor allergen exposure is a risk factor for sensitization during the first three years of life. J Allergy Clin Immunol 1997;99(6 Pt 1):763-9.
  2. 282. Corver K, Kerkhof M, Brussee JE, Brunekreef B, van Strien RT, Vos AP, et al. House dust mite allergen reduction and allergy at 4 yr: follow up of the PIAMA-study. Pediatr Allergy Immunol 2006;17(5):329-36.
  3. 283. Lau S, Illi S, Sommerfeld C, Niggemann B, Bergmann R, von Mutius E, et al. Early exposure to house-dust mite and cat allergens and development of childhood asthma: a cohort study. Multicentre Allergy Study Group. Lancet 2000;356(9239): 1392-7.
  4. 284. Arshad SH, Bateman B, Matthews SM. Primary prevention of asthma and atopy during childhood by allergen avoidance in infancy: a randomised controlled study. Thorax 2003;58(6):489-93.
  5. 285. Sporik R, Holgate ST, Platts-Mills TA, Cogswell JJ. Exposure to house-dust mite allergen (Der p l) and the development of asthma in childhood. A prospective study. N Engl J Med 1990;323(8):502-7.
  6. 309. Flaherman V, Rutherford GW. A meta-analysis of the effect of high weight on asthma. Arch Dis Child 2006;91(4):334-9.
  7. 310. Beuther DA, Sutherland ER. Overweight, obesity, and incident asthma: a meta-analysis of prospective epidemiologic studies. Am J Respir Crit Care Med 2007;175(7):661-6.
  8. 318. Cook DG, Strachan DP. Health effects of passive smoking-10: Summary of effects of parental smoking on the respiratory health of children and implications for research. Thorax 1999;54(4): 357-66.
  9. 319. Dezateau C, Stocks J, Dundas I, Fletcher ME. Impaired airway function and wheezing in infancy: the influence of maternal smoking and a genetic predisposition to asthma. Am J Respir Crit Care Med 1999;159(2):403-10.
  10. 320. Gilliland FD, Berhane K, McConnell R, Gauderman WJ, Vora H, Rappaport EB, et al. Maternal smoking during pregnancy, environmental tobacco smoke exposure and childhood lung function. Thorax 2000;55(4):271-6.
  11. 321. Lodrup Carlsen KC, Carlsen KH, Nafstad P, Bakketeig L. Perinatal risk factors for recurrent wheeze in early life. Pediatr Allergy Immunol 1999;10(2): 89-95.