Short-term pollen exposure ups risk for allergy, asthma symptoms

  • Kitinoja MA & al.
  • BMJ Open
  • 10 ene. 2020

  • de Miriam Davis, PhD
  • Clinical Essentials
El acceso al contenido completo es sólo para profesionales sanitarios registrados. El acceso al contenido completo es sólo para profesionales sanitarios registrados.

Takeaway

  • Allergy or asthma symptoms increase by 2% on short-term exposure to pollen, but with no effect on lung function, according to this meta-analysis of 12 studies.

Why this matters

  • This is the first meta-analysis of its kind amid conflicting results from individual studies.
  • Worldwide, approximately 500 million suffer from allergic rhinitis and more than 300 million have asthma.

Study design

  • A meta-analysis of 12 cohort studies after a search of PubMed and Scopus databases.
  • Short-term was defined as 10 grains/m3 increase in pollen exposure.
  • Funding: The Academy of Finland; others.

Key results

  • Short-term pollen exposure was associated with:
    • 1% increase in the risk for lower respiratory symptoms (effect estimate [EE], 1.01; 95% CI, 1.00-1.02);
    • 2% increase in the risk for any allergy or asthma symptom (EE, 1.02; 1.01-1.03);
    • 7% increase in the risk for upper respiratory symptoms (EE, 1.07; 1.04-1.09);
    • 11% increase in ocular symptoms (EE, 1.11; 1.05-1.17); but
    • No increase in daily lung function levels by spirometry.

Limitations

  • Small number of studies.