Asthma is a chronic lung disease with symptoms of coughing, wheezing, chest tightness, or shortness of breath. During an asthma attack, the sides of the airways in the lungs swell and the airways shrink, making it harder to breathe. Severe asthma attacks can be life-threatening and may require emergency room visits and hospitalizations.

Asthma can reduce quality of life by contributing to emotional and physical stress and may lead to missed time from school and work. Family history and environmental factors have been linked to asthma development. Certain factors, called triggers, can start or worsen asthma symptoms. These factors include pollen, viral infections like flu, or cold air. Triggers can be different for different people. Asthma can be managed by taking medicine and avoiding the environmental triggers that can cause an attack.

To improve the care of people living with asthma and help primary care providers and specialists make informed decisions about asthma management. Asthma management guidance is provided for six areas:

• Using inhaled corticosteroids when needed for recurrent wheezing or persistent asthma.
• Using long-acting antimuscarinic agents (LAMAs) with inhaled corticosteroids for long-term asthma management. A LAMA is a bronchodilator, a medicine that helps keep airway muscles relaxed.
• Using allergy shots that contain small amounts of allergen to treat some people with allergic asthma.
• Using methods to reduce exposure to indoor asthma triggers.

• Using a fractional exhaled nitric oxide test to help manage asthma or confirm a diagnosis. Nitric oxide can increase when there is airway inflammation.
• Using bronchial thermoplasty to treat selected adults with persistent asthma. During this procedure heat is used to reduce muscle around the airways.

Indoor triggers of asthma – Indoor air quality is a major concern for lung health. Dust mites, pests such as cockroaches and rodents, pet dander, molds, and fungi are common indoor triggers for asthma.

Healthy school environments can be important for reducing asthma risk in children. A study of inner-city students linked airborne mouse allergens in schools to increased asthma symptoms and decreased lung function in children.  This study suggests schools can take steps to improve air quality and help children who have asthma. Research has shown that inner-city children with obesity who live in homes with high levels of indoor air pollution may have worse asthma symptoms if they are also deficient in vitamin D.

Outside triggers of asthma - Researchers found babies who breathe high levels of traffic-related air pollution were more likely to have persistent wheezing during childhood, and children exposed to high levels of traffic-related air pollution through age 7 were more likely to develop asthma. The study found that adolescents exposed to nitrogen dioxide, an indicator of traffic-related pollution, experienced shifts in hormone levels that affect their response to stress, suggesting a way that air pollution might make asthma worse.

Asthma and a changing climate – Research has shown that natural disasters and extreme weather events, which are becoming more frequent with climate change, can create conditions that may worsen asthma.  For example, heat and drought make wildfires more widespread and severe, leading to large spikes in air pollution. Prolonged drought can worsen dust storms in dry areas. More intense rainfall and flooding can lead to mold growth in homes and commercial buildings.

The genetics of asthma – Asthma often runs in families, which suggests that genetics plays a role in disease development. LRF researchers have shown that asthma patients with a specific genetic makeup who live close to a highway are more likely to have intense symptoms. Another LRF study found that certain indicators within DNA may predict a newborn’s risk of asthma.  This information may help researchers identify which children may develop asthma and how to develop a treatment for preventing the disease.

Asthma and the immune system – The immune system, our body’s defense against infection, has a complex role in the development of asthma. A study showed that children who live on traditional Amish farms, which use animals rather than machines, were less likely to have asthma. The researchers suggest that the rich microbial environment on Amish farms may help build a stronger immune response in those children.  Although exposure to some bacteria and similar microbes can benefit the immune system, exposure to others can be harmful.

Asthma and occupational exposure – A study in mice that simulated agricultural dust exposures. They uncovered a novel role for the protein IL-22 in lung repair, and this finding could aid the development of therapeutics for farmworkers and others experiencing environmentally induced lung diseases, such as asthma. Many of whom were exposed to airborne contaminants, such as petroleum hydrocarbons — experienced increased risk of asthma.