“Some old-fashioned things like fresh air and sunshine are hard to beat” ~Laura Ingalls Wilder
When the long Minnesota winters start to melt away, one can’t help but welcome the warmth of the sun, fresh air, and the opportunity to spend more time outdoors. As the flowers and trees start to bloom, some people may notice a tickle in the back of their throat, itchy and watery eyes, an unrelenting sneeze, stuffy nose and in some cases coughing and wheezing. These symptoms could indicate an underlying allergy, referred to as allergic rhinitis (also known as rose fever or hay fever), and possibly asthma. It is estimated that allergic rhinitis affects 10-30% and asthma affects 7-14% of adults and children in the United States. Allergic rhinitis can be seasonal, typically caused by pollens (trees, grasses, weeds), and/or molds. It can also be year-round (perennial) due to indoor allergens, including dust mites, cockroaches, and animals. Allergic rhinitis requires 2-4 years of exposure to the allergen, so it is uncommon to see in children under the age of two years. Typically, symptoms due to allergic rhinitis either present in early school-aged children or later in life in young adults. Asthma is a chronic lung disease characterized by inflammation of the lungs leading to possible obstruction and airway hyper-reactivity, which can be triggered by colds/respiratory tract infections, exercise and most commonly, environmental allergens. Up to 50% of asthmatics also have underlying allergic rhinitis.
The field of allergy has historically considered environmental changes to play a significant role in the development of allergic conditions. These changes can include lifestyle changes (increased time indoors, rise in obesity, poor diet), increased exposure to indoor allergens (improved conditions for dust mites and mold indoors), and changes in hygiene (clean water, eradication of parasites, increased antibiotics use).
Today, growing evidence suggests the microbiome may play a role in shaping the immune system. The microbiome is the composite of microbes (bacteria, viruses, fungus), both helpful and harmful, occupying specific niches in the body. Alterations of the microbiome may lead to changes in susceptibility/development of certain diseases, including allergies and asthma. This process is a complex interplay between timing of exposure to certain microbes, diversity and abundance of the microbiome, location of microbes and microbial products. It has been hypothesized that the presence of certain bacteria or defined mixtures of bacteria in the gastrointestinal tract early on in life may be protective against the development of asthma and allergic rhinitis. Factors such as diet, mode of delivery (vaginal vs. cesarean section), and antibiotic use in childhood can alter the microbiome and may increase the susceptibility to certain diseases by disrupting this delicate balance.
We truly are at the tip of the iceberg when it comes to our knowledge of the microbiome. As we learn more about its role in our bodies and in the development of diseases, we can hopefully use this information to shape our microbiome and possibly identify windows of time when these alterations would be most beneficial.
As for now, for those suffering from allergies and asthma, seek advice from a board-certified allergist to help manage your disease.