Asthma

What is Asthma?

Asthma is a widespread long-term condition affecting the lungs and causing difficulty in breathing for millions of people around the globe. Asthma is characterized by inflammation in the airways, leading to occasional blockage of airflow and increased sensitivity in the bronchial tubes. Typical symptoms of asthma include coughing, wheezing, and shortness of breath. These symptoms often worsen due to triggers like allergens or viral infections. Various factors, including both genetic and environmental, determine the frequency and intensity of asthma.

It is important to note that despite progress in treatment methods, there are still inequalities in asthma care. These differences can be seen in the access to diagnosis, treatment, and patient education across different demographic groups.

Asthma often starts in childhood and is linked with other conditions like eczema and hay fever. The severity of asthma can range from intermittent symptoms all the way up to life-threatening closure of the airway. Doctors diagnose asthma based on the patient’s medical history, a physical examination, lung function tests, and appropriate lab tests. A type of lung function test known as spirometry is the main test used for diagnosis.

The focus of treating asthma is on continuous education about the condition, regular checking of symptoms, providing quick-relief inhalers, and prescribing the right long-term control medications depending on the severity of the disease.

What Causes Asthma?

Asthma is a disease influenced by a blend of genetic and environmental factors. Genes, specifically those located on chromosome 17q21, play a role in childhood asthma. Other genes related to immunity and inflammation, such as the IL33, IL1R1, and PYHIN1 genes, also have a connection to the disease. Interestingly, certain genes contribute not only to the occurrence of asthma but also its treatment, particularly those that may lead to a patient being resistant to glucocorticoids, a class of steroids used in treatment. Additionally, variations in the genes have been linked to response to asthma treatment in certain racial groups.

Studies have also revealed that environmental factors combined with certain genes may increase the risk for asthma. For example, exposure to secondhand smoke might connect variations in certain genes with the development of asthma in children.

Asthma risk factors can originate from exposures throughout a person’s life, starting from the prenatal period. Being born to a mother who is allergic to certain substances increases the chance of a child having asthma. At the same time, mothers who smoke, have a younger age, or lack vitamin D in their diets also raise the risk of their children developing asthma.

Diet has been linked to asthma too. Mothers who consume a lot of omega-3 fatty acids have a lower chance of their kids developing asthma compared to those with omega-6 fatty acid-heavy diets. Intake of vitamins C, E, zinc, and vitamin D can help protect against asthma. Furthermore, being born prematurely, before 36 weeks, comes with a risk of asthma in childhood and adulthood due to potential lung development issues.

In kids, viral infections and exposure to pollutants can predispose them to asthma. Factors such as obesity and early puberty also increase the risk. In adults, tobacco smoke, occupational hazards, rhinitis, and taking hormone replacement therapy after menopause have been identified as significant risk factors.

Lastly, certain diseases or conditions may result in asthma or make it worse. These include aspirin-exacerbated respiratory disease and occupational-induced asthma, both of which have a unique combination of patterns, triggers, and risk factors.

Risk Factors and Frequency for Asthma

Asthma affects approximately 260 million people globally. In different countries like India, Taiwan, Kosovo, Nigeria, and Russia, between 3.4% and 6% of adults and children have asthma. However, this rate rises to between 17% and 33% in countries such as Honduras, Costa Rica, Brazil, and New Zealand. Factors like inadequate prescription of inhaled glucocorticoids, limited access to emergency medical services, or specialist care contribute to the roughly 420,000 asthma-related deaths yearly, despite the continuous decline in the asthma death rate from 2001 to 2015.

In the United States, nearly 25 million people have asthma, with the distribution varying based on age, gender, race, and socioeconomic status. Notably, asthma is more common in boys under 18 than girls, but in adulthood, women are more affected than men. There’s higher prevalence among Black individuals (10.1%) compared to White individuals (8.1%), and Hispanic Americans generally have a lower prevalence (6.4%). Still, it rises to 12.8% for those from Puerto Rico. People from underrepresented minorities and those living below the poverty line have a higher incidence of asthma and related complications and deaths.

Much like the global trend, asthma mortality rate in the U.S. has been consistently dropping; currently standing at 9.86 per million, down from 15.09 per million in 2001. However, the death rates remain higher among Black patients compared to their White counterparts.

• Global asthma prevalence is about 260 million.
• In certain countries, between 3.4% and 6% of adults and children have asthma.
• This rate rises to between 17% and 33% in countries like Honduras, Costa Rica, Brazil, and New Zealand.
• In the US, close to 25 million people have asthma.
• Boys under 18 and adult women show higher asthma prevalence.
• Asthma is more common among Black individuals (10.1%) compared to White individuals (8.1%) and Hispanic Americans (6.4%), except those from Puerto Rico (12.8%).
• The asthma mortality rate in the United States has consistently declined from 15.09 per million in 2001 to 9.86 per million.
• Despite this decline, Black patients have consistently higher death rates due to asthma compared to White patients.

Signs and Symptoms of Asthma

Asthma, a chronic but treatable respiratory disease, is indicated by four main symptoms which are wheezing, coughing (which often worsens at night), difficulty in breathing, and tightness in the chest. A person with Asthma might experience one or more of these symptoms which typically happen intermittently and last for several hours to several days. These symptoms usually lessen or disappear when triggers are avoided or asthma medicines are used. Symptoms exacerbated at night, during exercise or due to exposure to triggers such as cold air and allergens suggest asthma. Unlike, exertional dyspnea which occurs shortly after one starts physical activity and resolves within five minutes of rest, symptoms of exercise-induced asthma typically begin around 15 minutes into exertion and lessen within 30 to 60 minutes of stopping the activity. Asthma is often associated with conditions like eczema and hay fever.

When taking a patient’s medical history, healthcare providers should inquire about any specific triggers that intensify symptoms. Everyday household triggers can include dust, pets, cockroaches or rodents. Some individuals may have asthma that is affected by their work routines. A strong family history of asthma, allergies, personal history of other allergic conditions and childhood asthma symptoms can suggest asthma in patients who are displaying similar symptoms.

During the physical examination, a characteristic finding of asthma is widespread, high-pitched wheezes. However, wheezing isn’t exclusive to asthma and may not be present between acute asthma attacks. Signs of a severe asthma attack can include rapid breathing, rapid heart rate, a lengthened phase of exhaling, difficulty in speaking in complete sentences, discomfort while lying down due to shortness of breath, assuming a “tripod position”. In addition, the use of the muscles which assist in breathing during inhalation and a condition known as pulsus paradoxus (abnormal decrease in pulse strength during inhalation) are also possible signs of a severe asthma attack.

Healthcare professionals may find other physical signs that suggest asthma, like pale, swollen nasal mucous membranes, bumps in the back part of the throat, nasal polyps (non-cancerous growths in the nose or sinuses), and atopic dermatitis (eczema). Presence of nasal polyps should warrant further inquiries about loss of the sense of smell, chronic sinus inflammation, and sensitivity to aspirin to evaluate for a condition known as AERD. In rare cases, if nasal polyps are found in children or adolescents with lower respiratory disease, it might indicate cystic fibrosis. The presence of clubbing (a medical condition with enlargement of the tips of fingers or toes), which is not related to asthma should prompt evaluation for other possible diseases.

Testing for Asthma

If you experience occasional asthma-like symptoms or wheezing when examined by a doctor, it might be a sign of asthma. To confirm this, other possible causes must be ruled out, and tests like spirometry are used to measure how much and how quickly you can move air out of your lungs.

A spirometry test involves taking a deep breath and blowing forcefully into a tube connected to a machine called a spirometer. This machine measures two key things: how much air you can blow out in one second (FEV1), and the total amount of air you can blow out (FVC). Asthma often shows up as a reduced FEV1 to FVC ratio, suggesting an obstruction that prevents air from leaving the lungs freely. However, sometimes the obstruction makes full exhalation impossible, in which case the ratio might look normal despite asthma’s presence.

After spirometry, you might take a medicine that opens your airways called a bronchodilator and then do the test again. An increase of 10% or more in your scores indicates a positive response, adding to evidence for asthma.

Sometimes the spirometry test is normal even when a person has asthma, especially if they are currently symptom-free or have a type of asthma that mainly causes a cough. Long-term asthma medications, recent use of bronchodilators, or underlying changes in the airway can also lead to a false negative result, so sometimes the test is done before treatment starts.

Another type of testing called bronchoprovocation can be used to check for asthma. This involves purposely causing the airways to constrict or tighten using inhaled drugs or other triggers, and then measuring how it affects your breathing. A decrease of 20% or more in your FEV1 indicates a positive test. Other triggers can also be used, such as exercise, aspirin, and exposure to workplace substances.

The peak flow test is used mainly to monitor known asthma rather than diagnose it. This test measures how quickly you can exhale by having you take a deep breath and blow into a tube quickly for 1-2 seconds. If the score drops by 20% or more during periods of symptoms, this suggests asthma.

Exhaled nitric oxide testing can provide additional evidence for asthma. In asthma patients, nitric oxide levels in the breath are often elevated. Oxygen levels in the blood can also be measured with pulse oximetry to determine the severity of an asthma attack or watch for any worsening.

Lab tests are not generally needed to diagnose asthma, but if you have a severe asthma attack, a complete blood count might be done to look at white blood cell types and check for other causes of shortness of breath. If you have persistent wheezing and are a non-smoker, testing for a rare condition called α1-antitrypsin deficiency might be done. Allergy testing can also be useful if you have symptoms linked to specific triggers.

Imaging tests like chest x-rays are often normal with asthma, but they may show changes like overinflation of the lungs or thickened bronchial tubes during an attack. A chest x-ray can also be useful to check for other conditions that can mimic asthma. Sometimes a high-resolution CT scan is needed for unclear x-ray results or suspected conditions that don’t show well on routine x-rays.

During an acute or severe asthma attack, your pulse, oxygen levels, and peak flow rate should be checked quickly. Chest x-rays are not always needed unless there is uncertainty about the diagnosis, you need to be admitted to the hospital, or there are signs of other health problems.

Finally, knowing if you have certain risk factors can help prevent severe or fatal asthma attacks. These include poor control of asthma, past severe attacks or intubation, and frequent asthma-related hospitalizations.

Treatment Options for Asthma

Various educational resources are available for patients with asthma. However, personalized guidance from your main healthcare provider can be most effective. Such education has been found to reduce asthma attacks and hospital stays. Medical professionals should offer asthma education that’s specific to each patient’s culture. This education should include understanding what asthma is, recognizing its symptoms, identifying what triggers your asthma and how to avoid these triggers.

Each patient should also know how to use an inhaler and understand the different types of medications available. These may include emergency or ‘rescue’ medications, those used to control symptoms, and some that do both. Doctors should also identify any issues a patient may have in sticking to their medication regimen and work with them to overcome any challenges.

Every person with asthma should have a personal asthma action plan. This plan outlines a routine for taking upkeep medications and guides the steps a patient should follow if their symptoms get worse. This plan, typically developed by the healthcare provider, is based on symptoms or peak flow readings and divided into three sections, or zones — green, yellow, and red.

The severity of a person’s asthma is determined by several factors such as the frequency and severity of symptoms, the degree of impaired breathing and the risk of future flare-ups. Treatment for asthma often comes in stages, with the highest severity category of symptoms designating the treatment level a patient will receive.

All patients should have access to a quick-acting bronchodilator medication, traditionally a short-acting β-agonist (SABA) such as albuterol. However, the Global Initiative for Asthma (GINA) recommends a low-dose glucocorticoid/formoterol inhaler for asthma symptoms.

Follow-up appointments are essential for managing asthma symptoms effectively. During these visits, patients can have their treatment protocols adjusted until their symptoms are under control. After maintaining control for a few months, it may be possible to gradually reduce the treatment following the protocols outlined by GINA or National Asthma Education and Prevention Program (NAEPP) guidelines.

Patients who experience an acute, or sudden, severe asthma attack may be able to manage symptoms at home or may need urgent medical care depending on their symptom severity and risk factors for serious asthma. These risk factors include life-threatening severe episodes in the past, episodes of asthma despite glucocorticoid use, more than one asthma-related hospitalization or three emergency room visits in the last year, or comorbid conditions like heart disease or chronic lung disease. Immediate medical attention should be sought for patients who exhibit significant difficulty breathing, inability to speak beyond short phrases, reliance on accessory muscles for breathing, or peak flow measurements at 50% or less than their baseline measurement.

Lastly, if you smoke and you have asthma, it is very important to quit. Medical professionals will typically provide you with resources and support to help you quit. Also, antibiotics are usually not helpful for asthma since most infections that trigger asthma are viral. Recommened standard of care excludes drugs like theophylline as they have been found ineffective.

What else can Asthma be?

When diagnosing asthma, the doctor must consider several other health conditions that could be causing the symptoms. These include:

• Bronchiectasis (damaged airways)
• Bronchiolitis (inflammation of the small airways)
• Chronic obstructive pulmonary disease (a lung disease characterized by long-term breathing problems and poor air flow)
• Chronic sinusitis (long-term sinus inflammation)
• Cystic fibrosis (a genetic disorder that affects mostly the lungs)
• α1-antitrypsin deficiency (a protein deficiency that can cause lung and liver disease)
• Aspergillosis (a reaction or allergic reaction to the fungus Aspergillus)
• Exercise-induced anaphylaxis (a severe allergic reaction to physical activity)
• Foreign body aspiration (lung irritation caused by inhaling an object)
• Heart failure
• Gastroesophageal reflux disease (stomach acid refluxing into the throat)
• Tracheomalacia (weakness and floppiness of the airways)
• Pulmonary embolism (blocked blood vessel in the lungs)
• Sarcoidosis (a growth of tiny collections of inflammatory cells in different body parts)
• Upper respiratory tract infection
• Vocal cord dysfunction (improper functioning of the vocal cords)
• Eosinophilic bronchitis (an inflammation of the airways)
• Bronchogenic carcinoma (type of lung cancer)
• Post-viral cough (a persistent cough that remains after a common cold or an upper respiratory tract infection)
• Cough induced by certain blood pressure medications
• Bordetella pertussis infection (whooping cough)
• Interstitial lung disease (a group of lung disorders that cause scarring of lung tissue)
• Obesity

Clearly, reaching an accurate diagnosis of asthma entails considering a variety of potential health conditions. It’s crucial to receive a comprehensive medical assessment to rule these out and ensure an effective treatment plan.

What to expect with Asthma

The development and outcome of asthma depend on a mix of inherited traits and environmental influences. Living conditions, such as low-quality housing and exposure to indoor and outdoor pollution, significantly affect the outlook for people with asthma. In the United States, asthma is a long-term health issue that disproportionately affects certain racial and ethnic groups, especially those who are often underrepresented or living in poverty. These groups usually suffer from higher rates of illness, more emergency room visits, hospitalizations, and increased number of deaths from asthma. The lack of access to healthcare—either due to difficulty in reaching medical professionals or not having insurance—makes these challenges even worse.

The worldwide death rate from asthma can be as high as 0.86 deaths per 100,000 people in some countries. Lung function is tied closely to the overall outlook, with the death rates being eight times higher in individuals whose lungs function at the bottom 25%. A number of factors can make the outlook worse, such as inadequate control of asthma, being over the age of 40, having a history of smoking more than 20 packs of cigarettes a year, having high levels of eosinophils (a type of white blood cell) in your blood, and scoring between 40% to 69% of the expected value on a lung function test called FEV1.

Possible Complications When Diagnosed with Asthma

People with asthma can face a range of complications related to the disease and the medications used to treat it. These concerns also include the side effects of certain drugs like glucocorticoids, Leukotriene receptor antagonists (LTRA), as well as complications from procedures like endotracheal intubation (a tube placed into the windpipe through the mouth or nose).

The following are potential complications associated with asthma:

• Decline in lung function
• Osteoporosis – Weakening of bones
• Fractures
• Infections
• Adrenal suppression – A condition that affects the adrenal glands’ ability to produce hormones
• Hypertension – High blood pressure
• Diabetes
• Cataract – Clouding in the lens of the eye causing vision loss
• Peptic ulcers – open sores that develop on the inner lining of the stomach and upper portion of the small intestine
• Sleep disorders
• Obstructive sleep apnea – Breathing abruptly starts and stops during sleep
• Mood disorders – like depression and anxiety
• Cardiac arrest – Sudden loss of heart function
• Glaucoma – a group of eye conditions that damage the optic nerve, often due to high pressure in your eye
• Respiratory failure or arrest – Severe decrease in the ability to breathe
• Pneumothorax – Collapsed lung
• Aspiration – Inhalation of food, stomach acid, or saliva into the lungs

Preventing Asthma

Teaching patients about their condition is crucial in managing asthma effectively. Medical professionals should stress the importance of sticking to medicine routines, avoiding things that trigger asthma, and regularly checking symptoms. In learning about what might trigger an asthma attack like allergens, pollution, and tobacco smoke, patients are opened up to make smarter choices about their lifestyle.

Apart from knowing this, doctors should underscore the importance of having an ‘asthma action plan’. This is a guide that can help patients know what to do if their symptoms get worse. The National Heart and Lung Institute has a downloadable version of this guide, which can be found on their website under “Asthma Action Plan”.

Furthermore, teaching patients to recognize the early signs of an asthma attack and when to seek medical help is also important. Regular check-ups every one to six months are recommended for active asthma patients – this depends on how severe the asthma is and how well it’s being controlled. This is the perfect time for medical professionals to check on how well a patient’s asthma is being managed, how well their lungs are functioning, how they’re using their inhaler, how they’re coping with the medicine, their overall quality of life, and their satisfaction with the care they’re receiving. Through strengthening the patients’ knowledge of how to manage their asthma and encouraging their active involvement, medical professionals can greatly lessen the impact of asthma on the patient’s life.