What is Allergic and Environmentally Induced Asthma?
The National Heart, Lung, and Blood Institute defines asthma as a long-term inflammation disorder. Various cells, like mast cells, eosinophils, macrophages, neutrophils, T-lymphocytes and epithelial cells, play a part in creating this inflammation. This inflammation can cause asthma symptoms like shortness of breath, wheeziness, coughing and a tight feeling in the chest.
Asthma is a condition that narrows the airways in your lungs making it hard to breathe out. It can happen suddenly and can often be reversed, and is characterized by airflow blockage due to inflammation, bronchospasm (sudden contracting of the airway muscles) and excess fluid in the airways. Asthma affects all races, ages, genders, and ethnicities, and it’s calculated that 7% of Americans live with it. The occurrence of asthma and related conditions has significantly grown in western countries. Despite its high occurrence, improvements have been made in managing it resulting in less hospitalizations from asthma attacks. Asthma comes with symptoms such as wheezing, an overly reactive airway responding to various triggers, and blocked airways. These symptoms can happen several times a day or several times a week, depending on the individual. Guidelines from the National Asthma Education and Prevention Program Expert Panel recommend that people who need daily asthma medication should be tested for allergies to year-round indoor and outdoor allergens.
What Causes Allergic and Environmentally Induced Asthma?
Asthma is caused by a mix of genetic and environmental factors. But the main cause of all types of asthma is a heightened sensitivity reaction. This reaction happens when something harmful, like an allergen or environmental pollutants, trigger an increase in certain immune cells in our body. This then leads to inflammation and damage to the inside of the air tubes in the lungs. Certain cells called cytokines also contribute to the development of asthma. Changes in the muscle lining the air tubes also play a part. Allergic reactions to certain substances are often associated with asthma attacks.
The highest risk factor for getting asthma is a history of diseases related to allergies, such as hay fever or eczema.
Environmental triggers for asthma can include exercise, heavy breathing, changes in hormones, emotional distress, airborne pollutants, and even conditions like GERD (Gastroesophageal reflux disease).
The severity of asthma can also be affected by environmental pollution – it might act as a trigger, worsening an existing inflammation in the air tubes.
Many studies have shown the role of allergies and allergens in triggering asthma.
When considering triggers for asthma, both indoor and outdoor allergens and pollutants should be kept in mind. These include:
- Biological allergens like dust mites, cockroaches, animal hair, and mold
- Environmental tobacco smoke – smoking during pregnancy and after delivery increases the risk of developing asthma
- Irritant chemicals and fumes like traffic pollution and high ozone levels
- Combustion device products
Asthma is the most common lung disease in industrialized countries and makes up 15% of new adult asthma cases, particularly related to the work environment. This is known as Occupational asthma and can be caused by allergens or irritants at the workplace.
An emerging theory known as the ‘hygiene hypothesis’ suggests that extremely clean environments that restrict childhood exposure to triggers and infections can make the immune system less experienced, increasing the odds of asthma and allergies.
Risk Factors and Frequency for Allergic and Environmentally Induced Asthma
Astma is a common condition affecting almost 1 in 13 people, according to a report by the Centers for Disease Control and Prevention (CDC). This translates to around 25.7 million Americans being impacted by asthma, including 7 million children under the age of 18. Asthma’s impacts are far-reaching, causing issues not only for those suffering from it, but also placing a significant burden on their families and society as a whole.
- In 2010, asthma was the reason for 1.8 million emergency room visits and led to the hospitalization of 439,000 people.
- Recent data from the CDC reveal that around 6.5% of males and 9.1% of females are affected by asthma.
- Looking at it from a racial perspective, 7.8% of the white population, 10.3% of the black community, and 6.6% of the Hispanic population have asthma.
- The World Health Organization (WHO) estimates around 235 million people around the world are currently dealing with asthma.
Asthma also affects individuals in the workplace, with the annual number of new, work-related asthma cases ranging from 12 to 170 per million employees. The condition is fairly prevalent in many industries, affecting 5% to 15% of workers. Among non-communicable diseases, asthma is the most common in children. However, the majority of asthma-related deaths occur in older adults.
Signs and Symptoms of Allergic and Environmentally Induced Asthma
When diagnosing asthma, doctors consider a few specific details from the patient’s history:
- The start of symptoms
- The presence of environmental triggers both indoors and outdoors, as well as risk factors like tobacco exposure
- Current treatments and prior episodes
- A history of hospitalization or the need for a breathing tube due to asthma
- The patient’s job (90% of occupational asthma is caused by sensitizers, and 10% by irritants)
- Food allergies
- Symptoms of gastroesophageal reflux disease (GERD)
- The use of drugs like NSAIDs and aspirin
- Shortness of breath triggered by exercise
Asthma symptoms include:
- Coughing
- Shortness of breath
- Wheezing
- A feeling of tightness or pressure in the chest
During an acute asthma attack, doctors might observe:
- Rapid breathing
- Wheezing
- The use of extra muscles for breathing
- Indentation in the skin between the ribs when breathing
- A longer than normal time to exhale
- In severe cases, limited air movement
Common sensitizers that can trigger occupational asthma include animals, certain airborne biological materials, drugs, enzymes, latex, plants, seafood, acid anhydrides, metals, wood dust, persulfate, rosin, and isocyanates. Irritants that can cause asthma include chlorine and high levels of dust and smoke.
Testing for Allergic and Environmentally Induced Asthma
If you’re being evaluated for possible asthma, several tests might be used. These include pulse oximetry, peak flow tests, and spirometry–which measures your ability to breathe out forcefully. Improving more than 12% on a spirometry test or increasing by 200 millilitres after using a bronchodilator (a medicine that helps open up your airways) supports an asthma diagnosis. Other tests might include a chest x-ray, or a flu or RSV swab if a virus might have triggered your symptoms. A blood gas test might be needed if your symptoms are severe.
If you’ve recently started having asthma and it could be related to your job, there are further tests your doctor might order. These include measuring peak flow, more spirometry, peak expiratory flow rate monitoring both in and outside of work, and skin tests for allergies. There are also specific inhalation tests and a methacholine challenge, which tests how sensitive your lungs are.
Researchers are looking into how useful biomarkers of inflammation might be in diagnosing asthma. Biomarkers are substances in your body that can give clues about how your body is functioning, and these might be found in your sputum, blood, urine, or exhaled air.
According to the National Asthma Education and Prevention Program Expert Panel guidelines, people who need daily asthma medication should have allergy tests for indoor allergens. If triggers are found, various methods should be used to limit exposure. If this isn’t enough to control symptoms, you might be referred to an allergist for a treatment called immunotherapy.
Asthma severity is categorized as intermittent, mild persistent, moderate persistent, or severe persistent. There are several validated questionnaires used to check how well your asthma is controlled, such as the Asthma Assessment questionnaire, the Asthma Control Questionnaire, and the Asthma Control Test. These should be used to work out your initial treatment. Asthma control should then be checked regularly to decide on a treatment plan.
Treatment Options for Allergic and Environmentally Induced Asthma
The main goal in treating asthma is to reduce the frequency and severity of symptoms, as well as prevent future asthma attacks and any decrease in lung function or side effects from medication. This is usually achieved through a diverse approach that includes right medication, managing environmental factors that worsen symptoms, and educating patients on how to manage the condition and adjust treatments as necessary.
Asthma medications fall into two categories: quick relief and long-term control. Quick-relief medications, such as fast-acting inhalers that use albuterol, are needed for all patients to use when needed. If these are used more than two days a week or twice a month at night, a long-term control medication should be used. Long-term control of asthma typically involves avoiding environments that can inflame the airways, monitoring changes in the condition, and sometimes using drug therapy or allergen immunotherapy. Inhaled corticosteroids are often effective in managing asthma long-term, as they can lessen the inflammation and sensitivity of the airways.
The “step-up” therapy approach is used to achieve the goal of controlling asthma:
1. For intermittent asthma, use a quick-relief inhaled drug. For persistent asthma, daily medication is necessary.
2. Use a low-dose inhaled corticosteroid.
3. The preferred treatment is adding a long-term inhaled drug to a low-dose inhaled corticosteroid, or using a medium-dose inhaled corticosteroid.
4. Use a medium-dose inhaled corticosteroid plus a long-term inhaled drug.
5. Use a high-dose inhaled corticosteroid plus a long-term inhaled drug. Consider using omalizumab if the person has allergies.
6. Use a high dose inhaled corticosteroid, a long-term inhaled drug, and an oral corticosteroid. Consider omalizumab if the person has allergies.
From step 2 to 4, allergy testing and immunotherapy can be considered. Other drugs like leukotriene receptor antagonists, cromolyn sodium, and theophylline can be alternatives, but they’re not the preferred choice.
Follow-up is based on symptom control, frequency of using quick-relief inhaler, nighttime awakenings, and interference with activities. Factors like medication adherence, inhaler use, environment, and other health conditions should be evaluated. If asthma has been controlled for at least three months, therapy may be decreased.
Using spacers (a device that allows the medication to be inhaled more easily) with inhalers is recommended, especially for children.
Reducing exposure to potential allergens and triggers, like dust mites, pets, cockroaches, fungi, air pollution, and tobacco smoke, can also be very important in controlling asthma.
If a person has an acute asthma attack, they should get immediate medical care, particularly if their airflow is severely restricted. Medications can include a combination of inhaled anticholinergic and beta2 agonist treatments, intravenous magnesium sulfate, and systemic corticosteroids. After a severe attack, patients should typically take oral prednisone.
What else can Allergic and Environmentally Induced Asthma be?
Before starting treatment for asthma, it’s crucial to ensure that the patient isn’t suffering from a different condition with similar symptoms.
For adults, these other conditions could include:
- Chronic obstructive pulmonary disease (COPD)
- Congestive heart failure
- Gastroesophageal reflux disease (heartburn)
- Blockage of the airways
- Problems with the vocal cords
- Sleep apnea
- Mental health issues like depression or stress
Although less common, it’s also possible that symptoms could be caused by:
- Blood clot in the lungs (pulmonary embolism)
- Infiltration of the lungs
- Reactions to certain medications, such as ACE inhibitors
Identifying whether a child has asthma, or another cause of wheezing can be tricky. In children, wheezing could potentially be caused by:
- Allergic reactions or sinusitis
- Blockage of large airways, possibly due to a foreign body or a growth
- Issues with the vocal cords
- Abnormalities or obstructions in the airways
- Small airway obstructions, possibly due to a virus or genetic disorders like cystic fibrosis
- Bronchopulmonary dysplasia (a lung disease typically affecting preterm infants)
- Cilia-related issues
Wheezing could also be caused by several other things, including:
- Congenital heart disease
- A persistent cough not related to asthma
- Aspiration (breathing foreign material into the lungs)
- Gastroesophageal reflux (stomach acid backing up into the throat)
What to expect with Allergic and Environmentally Induced Asthma
The outlook for asthma varies between adults and children. Kids often get better more often than adults. However, the illness typically won’t get much worse in either group unless they also have other lung problems like chronic obstructive pulmonary disease (COPD) or a history of tobacco use. Studies have also found that those who’ve been severe enough to need hospital treatment or the use of a breathing tube have a worse outlook. Those who smoke and have underlying COPD have a worse outlook too, and can sometimes result in lasting damage to the lungs.
Many new studies suggest that starting inhaled steroids early, and using them regularly, can have a positive effect and can improve how well the lungs work.
Possible Complications When Diagnosed with Allergic and Environmentally Induced Asthma
Asthma, while usually manageable, can sometimes lead to complications. These are not generally long-term, but they can still significantly impact a person’s life.
Common Complications:
- Interference with normal activities
- Disruption of sleep
- Missing time from school or work
- Needing to visit the emergency department or be hospitalized
However, there can still be long-term complications from asthma. These usually occur due to the chronic inflammation caused by frequent asthma attacks, which can damage the airways. Over time, this can make it difficult for medications to properly reach the airways. Deaths from asthma are uncommon, but the risk can be higher for those who have underlying lung disease or who smoke.
Preventing Allergic and Environmentally Induced Asthma
Individuals with asthma need to be informed about their medications in order to manage their condition effectively. It’s crucial that they understand the proper usage of these medications and the difference between quick-relief medications and daily control medications like inhaled steroids.
Developing and using an asthma action plan is also important. This plan provides guidance on recognizing severe symptoms and helps them know when to seek help from a doctor or head to the emergency room.
There’s a tool called the Asthma APGAR (Activities, Persistence, Triggers, Asthma medications, Response to therapy), primarily used in general practice. Studies show that this tool helps improve asthma control, lowering the need for emergency room or urgent care visits.