Outdoor air pollution and asthma - 2014 Lancet review

Distances within 300-500 m of roadways affect human health. In large North American cities, 30-45% of people live near a major roadway. Patients with asthma should ideally live at least 300 m from major roadways, especially those with heavy truck traffic. In-vehicle exposure during commuting with open windows can also be very high. Air pollutants cause oxidative injury to airways, leading to inflammation, remodeling, and increased sensitization.

14% of incident asthma and 15% of all exacerbations of childhood asthma are attributed road traffic pollutants. Air pollution can cause exacerbations of pre-existing asthma but it also might cause new-onset asthma. Cities with rapid economic and population growth (China and India) have some of the worst air quality in the world. Short-term exposures to ozone, nitrogen dioxide, sulphur dioxide, PM2·5, and TRAP is thought to increase the risk of exacerbations of asthma symptoms.

This comprehensive review from The Lancet presents a snapshot of our current understanding of the relationship between outdoor air pollution and asthma (free full text after registration).


Outdoor air pollution and asthma. Michael Guarnieri et al. The Lancet, Volume 383, Issue 9928, Pages 1581 - 1592, 3 May 2014, doi:10.1016/S0140-6736(14)60617-6

Trends in the age of diagnosis of childhood asthma: a study of 1 million children

8 consecutive birth cohorts of children (1993-2000) were observed using the universal health insurance plan in Ontario, Canada.

The records of 1,059,511 children were examined, of whom 19% developed asthma in the first 8 years of life. Mean age at asthma diagnosis decreased from 4.7 years in birth year 1993 to 2.6 years in birth year 2000.

This study demonstrates an increase in asthma incidence and a decrease in the age of asthma diagnosis across multiple birth cohorts.


Trends in the age of diagnosis of childhood asthma. J Allergy Clin Immunol. 2014 Jun 27. pii: S0091-6749(14)00671-X. doi: 10.1016/j.jaci.2014.05.012. [Epub ahead of print]

High daily temperatures worsen respiratory symptoms in children with asthma, decrease PEF

An Australian national panel study of diurnal temperature range (DTR) and children's respiratory health

This study examined effects of DTR on lung function and respiratory symptoms for school children with asthma in Australia.

Increase in daily temperature induced a reduction in PEF and increased respiratory symptoms in children with asthma. The effects lasted for 3 days.


An Australian national panel study of diurnal temperature range and children's respiratory health. Annals of Allergy, Asthma & Immunology, Volume 112, Issue 4, Pages 348–353.e8, April 2014.

Image source: OpenClipArt.org, public domain.

Metal hypersensitivity in total joint arthroplasty

This literature review was published in Ann Allergy Asthma Immunology in 2014.

Total joint arthroplasty procedures are increasing, as are the hypersensitivity reactions to these implants. We don't know if metal joint implants increase metal sensitivity or whether metal sensitivity leads to prosthesis failure.

How to diagnose metal hypersensitivity in total joint arthroplasty ?

Patch testing is still the most widely used method for determining metal hypersensitivity. However, there are no standardized commercial panels specific for total joint replacements available at this time.

In vitro testing has shown comparable results in some studies. However. its use in the clinical setting may be limited by the cost and need for specialized laboratories.

Hypersensitivity testing is generally recommended before surgery for patients with a reported history of metal sensitivity.

In cases of metal hypersensitivity-related joint failure, surgical revision ultimately may be required.

Evaluation of hypersensitivity reactions after total joint arthroplasty requires a systematic approach, including:

- careful history
- targeted evaluation with skin testing
- possibly in vitro studies


Metal hypersensitivity in total joint arthroplasty. Pinson ML1, Coop CA2, Webb CN2. Ann Allergy Asthma Immunol. 2014 Jun 13. pii: S1081-1206(14)00337-8. doi: 10.1016/j.anai.2014.05.012. [Epub ahead of print]

Image source: Edheads.org

A Mom's Thoughts on Food Allergies - ACAAI video

From ACAAI YouTube channel: Emily Kloser is the mom of two kids with food allergies. Both of her children are champion athletes. She shares what she's learned over the years about coping with food allergies.

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