Inhalant allergies are a common problem that affects millions of people worldwide. Symptoms such as rhinorrhea, congestion, sneezing, and irritated eyes are caused by a wide range of environmental triggers, including natural and man-made pollutants in the air. With a prevalence of 10-40% depending on the geographical location, it is essential to understand the risk factors associated with this condition to provide the best treatment options.
Acute Immune Mechanism
Allergic rhinitis is caused by initial allergen exposure and sensitization, involving multiple different immune cells, including antigen-presenting cells, T and B lymphocytes, allergen-specific T cells, and IgE antibodies. The repeated exposure leads to the binding of IgE cross-linked antibodies onto mast cells, causing the release of allergic chemical mediators such as histamine. This release leads to the symptoms of allergic rhinitis, followed by a secondary allergic inflammatory response with Th2 lymphocytes, eosinophils, and basophils infiltrating the nasal mucosa, causing a late allergic response.
Risk Factors
Chronic Immune Dysfunction
Long-term allergies, including allergic rhinitis, are associated with a chronically elevated Thelper 2 cells (Th2) response. This ongoing elevated Th2 response is a common immune imbalance in chronic patients. With inflammation, especially inflammation arising in hollow organs such as the intestines and the lungs, there is an increase in Thelper 17 cells (Th17) and a decrease in T regulatory (Treg) cells. An increase in Th17 cells with a concomitant lowering of Th1 cells leads to the development of autoimmune disease.
Hygiene Hypothesis
The decrease in infectious disease exposure in young children has caused a decrease in Th1 immune responses needed to fight infections. This decrease in Th1 immune response leads to a shift toward an increase in Th2 immune responses associated with allergic diseases.
Abnormal Microbiome
Multiple studies have looked at the types of bacteria in the intestinal microbiome and found decreased diversity in those with allergies. An altered microbiome is associated with chronic illnesses and an immune system imbalance so it makes sense that it would be associated with an increase in allergic rhinitis and other atopic diseases.
Pregnancy and Postpartum Issues
The maternal microbiome influences the fetal immune system by aligning the maternal and infant regulatory immune balance. Maternal allergy can impact an infant’s allergy potential. The mode of delivery and breastfeeding can also influence the microbiome of the infant. A woman’s diet during pregnancy and breastfeeding can also influence allergy potential in their child.
Climate Change
Climate change has resulted in an increase in allergic pollen and air pollution, both contributing to rising rates and severity of the atopic disease. Carbon dioxide leads to the growth of plant species, such as ragweed, that thrive at high carbon dioxide concentrations. Air pollution, such as ozone, nitric oxide, diesel exhaust, and other volatile organic chemicals (VOC), has also increased because of climate change. Inhaled air pollutants cause inflammation, oxidative stress, and increased permeability in the airways, which can increase the uptake of allergens.
Genetics
Allergic disease is considered primarily polygenic because searching for specific genes has only shown a few specific single nucleotide polymorphisms (SNPs). Epigenetic changes from DNA methylation and histone modification modify the influence of environmental exposures such as air pollution, contributing to the rising rates of allergic diseases.
Treatment Options
An integrative approach to allergic rhinitis involves a combination of treatments that address the underlying cause and provide relief from symptoms. Transfer factors, probiotics, and natural histamine receptor blockers are effective in balancing the immune system, from an elevated Th2 allergic-promoting response.
Therefore, supporting the immune system in shifting away from this response can be helpful in reducing symptoms. One way to do this is through the use of transfer factors, which are small proteins that can help balance the immune system. Probiotics are another option for immune modulation, as they can impact the types of gut flora and influence the immune response.
Vitamin D and Vitamin C
Vitamin D has been found to be associated with an increased risk of allergic rhinitis, so ensuring adequate levels of this nutrient is important for those who suffer from seasonal allergies. Vitamin D can be obtained through sun exposure and diet, but supplementation may also be necessary. Additionally, vitamin C is often combined with quercetin, a flavonoid that has been found to have anti-allergenic, antioxidant, and anti-inflammatory properties. Vitamin C can also act as a natural antihistamine and may be helpful in reducing symptoms.
Nasal Irrigation
Nasal irrigation is another natural approach that can be helpful for managing seasonal allergies. This technique involves flushing the nasal passages with a saline solution to remove allergens such as pollen, dust, and air pollution. Nasal irrigation can be done using a neti pot or a nasal spray and can be especially effective when done regularly.
Conclusion
As the prevalence of seasonal allergies continues to increase, it is important to understand the underlying causes and consider natural approaches for managing symptoms. Immune modulation, adequate levels of vitamin D and vitamin C, probiotics, natural antihistamines (Nigella, Quercetin), and nasal irrigation are all effective strategies for reducing the severity of seasonal allergy symptoms. By incorporating these natural approaches into a comprehensive treatment plan, individuals can find relief from their allergy symptoms and support overall immune health.
