New Canadian research suggests that exposure to commonly prescribed antibiotics increases both the incidence and severity of allergic asthma in children.

Allergic asthma affects more than 100 million people worldwide and its prevalence is increasing on average by 50 per cent every decade, particularly among children in industrialized countries. According to the Asthma Society of Canada, asthma affects at least 12 per cent of Canadian children.

Over the past decade or so a rapidly growing body of research has made it apparent that the composition of our gut microbiota - that is, the microbes that inhabit our guts - play a large role in regulating our immune systems. Anything that disrupts the delicate balance of this microscopic ecosystem has the potential to cause immune dysfunction. Not surprisingly, antibiotic drugs which wipe out bacteria in the gut, as well as at the site of any infection intended to be treated, can have significant consequences not foreseen until recently.

A new study reveals that exposure to non-sensitising air pollution at work significantly increases a man's risk of developing adult-onset asthma but has no corresponding effect in women.

It is now well established that acute workplace exposure to high levels of sensitising chemicals, including chlorine, ammonia, ozone and sulphur dioxide, can trigger so called reactive airway dysfunction syndrome (RADS) and cause late-onset asthma in adults. There has been much less research looking at chronic low level exposure to air pollution considered non-sensitising, such as dust, smoke and fumes from non-sensitising chemicals. The suggestion that such low-level chronic exposures can cause asthma has generated a not unsubstantial amount of debate, much like the issue of chronic low-level chemical exposures leading to multiple chemical sensitivity (MCS).

A Swedish research team sought to clarify the role of chronic low-level exposure to non-sensitising air pollutants in adult-onset asthma  and address the controversy surrounding the issue. The scientists, based at the Clinic of Occupational and Environmental Medicine, University Hospital, Linkoping, designed a case-control study involving 192 adult-onset asthma cases and 323 healthy control subjects, all aged between 20 and 65.

A new study reveals that children with low vitamin D levels are more likely to suffer from both food allergies and inhalant allergies.

Researchers found a link between allergies to ragweed, oak, dogs, cockroaches, shrimp and six other allergens and vitamin D deficiencies. There was a strong relationship to peanut allergy, one of the most common food allergies and one which causes significant problems for children due to hidden traces of peanut proteins in many foods.

In this large scale epidemiological study a team of American researchers analysed blood samples from 3,136 children and adolescents and 3,454 adults to look for any links between serum vitamin D levels and sensitivity to 17 different allergens. Confounding factors such as milk consumption, obesity and socio-ecomonic status, which could affect the results, were also taken into account. The results of the study are published in the Journal of Allergy and Clinical Immunology.

A new study has revealed that a total of 7.5 million Americans, or 2.5 percent of the population, are currently suffering from a diagnosable food allergy to at least one food.

The study, which is thought to be the largest of its kind so far conducted, found young black children who also suffer from asthma appear to be the group most at risk. The research was a collaborative effort by investigators at institutions including Johns Hopkins Children's Center and the National Institutes of Health (NIH).

The study involved 8200 participants from age 1 to 60+ who gave blood samples and were interviewed by researchers. The investigators used the data collected to determine the prevalence of four food allergies and also to look at the association between food allergies and asthma, eczema and hay fever, known collectively as atopic illness. The findings are published in the Journal of Allergy and Clinical Immunology.