The Global Burden of Asthma in Children

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Asthma is the most common chronic disease in children, although the prevalence and severity of asthma in the last 30 years varies based on country income, region, and center. Nevertheless, the worldwide burden of severe asthma is definitely high. As physicians, it is our responsibility to not only educate parents on how to identify the symptoms of asthma early on but also enable prompt access to effective asthma therapies.

Asthma

Asthma is a respiratory disease involving chronic inflammation of the lower airway mucosa1. Hyperresponsiveness of the airway is its key physiologic abnormality. Allergens, sensitizers, viruses, and air pollutants trigger these hyperresponsive airways, leading to inflammation of the respiratory mucosa from the trachea to terminal bronchioles. The inflammation causes narrowing of the airways, which obstructs airflow. Inflammatory cells such as mast, macrophage, dendritic, and eosinophilic cells are key players in asthma. All these physiological responses lead to the symptoms of cough, wheezing, chest tightness, and dyspnea.

Since asthma is a chronic condition, this leads to a cycle of inflammation and repair that may cause remodeling of the airways. Airway epithelium may become fibrosed, compounding the effects of asthma. There is also fibrosis of the basement membrane, resulting in irreversible narrowing of the airways. Additionally, hypersecretion of mucus can also lead to viscous mucus plugs that may block airways.

Overall, we can see that asthma is a chronic disease that can negatively affect a child’s quality of life. It is therefore important that you, as medical practitioners, educate parents on asthma as soon as possible.

Risk Factors

Risk factors are genetic and environmental elements that predispose a person to develop a particular disease. Here are the risk factors for asthma1:

• Atopy — Usually found in 40–50% of the population in affluent countries; found in over 80% of patients with asthma
• Genetic predisposition — High degree of familial association
• Infections — Although still uncertain, viral infections (especially rhinovirus) and atypical bacteria (Mycoplasma pneumoniae and Chlamydophila) have been implicated in asthma
• Diet — Diets low in antioxidants like vitamin C, vitamin A, magnesium, selenium, and omega-3 polyunsaturated fats are associated with an increased risk of asthma
• Obesity
• Air pollution — Exposure to sulfur dioxide, ozone, nitrogen oxides from cooking stoves, and secondhand cigarette smoke is associated with an increased risk for asthma

By educating parents on the risk factors associated with asthma, we can equip them better to detect asthma early on. They may also address modifiable risk factors and triggers, like avoiding smoking in the house, to lessen the risk of children developing asthma or having an asthma attack.

Triggers

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There are certain stimuli that may trigger someone’s asthma1. When this happens, the patient may present with a narrowing airway, wheezing, and dyspnea. It is important to address asthma triggers as a compliment to the controller medications that you provide. Here are some of the most common asthma triggers:

• Allergens — House mites, grass, pollen, animal fur, and cockroaches may all trigger asthma
• Virus infections — Upper respiratory tract infections (like rhinovirus, respiratory syncytial virus, and coronavirus) are the most common triggers of acute asthma exacerbations
• Pharmacologic agents — Aspirin and beta-adrenergic blockers acutely worsen asthma and may be fatal
• Exercise — Hyperventilation triggered by exercise may lead to bronchoconstriction; this typically begins after exercise has ended and resolves spontaneously within 30 minutes; winter sports such as skiing and ice hockey may worsen asthma
• Physical factors — Cold air, hyperventilation, laughter, strong smells or perfumes
• Food and diet — Metabisulfite (food preservative) and tartrazine (yellow food coloring) may trigger asthma

At every consultation, medical practitioners should educate parents on the importance of addressing asthma triggers at home. Taking measures to ensure a clean and dust-free home will not only protect everyone’s health but also eliminate any pesky triggers that may constantly be triggering asthma.

Diagnosis

The diagnosis of asthma2 in young children is largely based on recurrent symptom patterns. This should be paired with a thorough history and complete physical examination. Asthma is likely if there is a positive family history of allergic disorders or the presence of atopy or allergic sensitization. The child is likely to have asthma if they present with:

• A cough, wheeze, or heavy breathing for more than ten days during upper respiratory tract infections
• More than three asthmatic episodes per year, or severe episodes and/or night worsening
• Between episodes, the child has a cough, wheezing, or heavy breathing during play or when laughing
• Positive allergic sensitization, atopic dermatitis, food allergy, or family history of asthma

To accurately take note of these symptoms, here are some questions you can ask parents to elicit features that are suggestive of asthma:

• Does your child wheeze? Wheezing is a high-pitched noise coming from the chest, not the throat.
• If the parent is unsure, you may ask them to take a video of potential episodes for confirmation.
• Does your child wake up at night because of coughing, wheezing, or difficulty breathing?
• Does your child have to stop running or play less hard because of coughing, wheezing, or difficulty breathing?
• Has your child ever had eczema or been diagnosed with an allergy to foods?
• Has anyone in your family had asthma, hay fever, food allergy, eczema, or any other disease with breathing problems?

As most of us know, the key to clinching the right diagnosis is a thorough history and complete physical examination. A keen eye for detail and noting symptom patterns will aid in the diagnosis of asthma.

Treatment

Since asthma involves inflammation of the airways, the goal of treatment is to reduce this inflammation. In young children, asthma treatment follows a stepwise approach. This means that medication may be adjusted upwards or downwards to achieve good symptom control. This will also minimize the risk of future asthma exacerbations and medication side effects. Throughout the treatment process, it is important to continuously review, assess, and adjust treatment accordingly.

Step 1: As-needed inhaled short-acting beta2-agonist (SABA)

• For children with infrequent viral wheezing and no or few interval symptoms

Step 2: Initial controller treatment (inhaled corticosteroids, ICS) plus as-needed SABA

• For patients whose symptom pattern is not consistent with asthma but who have frequent wheezing episodes requiring SABA
• For patients whose symptom pattern is consistent with asthma, and asthma symptoms are not well-controlled or >3 exacerbations per year

Step 3: Additional controller treatment, plus as-needed SABA, and consider specialist referral

• For patients with an asthma diagnosis and asthma not well-controlled on low-dose ICS
• Before stepping up, check for an alternative diagnosis, check inhaler skills, and review adherence and exposures

Step 4: Continue controller treatment and refer for expert assessment

• For patients whose asthma is not well-controlled and on double ICS

At every visit, make it a point to assess asthma control, risk factors, and side effects of medications. A follow-up visit should be scheduled 3–6 weeks after therapy has been adjusted. You should also provide the parent/caregiver with a written asthma action plan. This should involve explaining to the caregiver to watch out for signs of worsening asthma, which medications should be given to treat it, and when to contact medical care. This way, care is adequately continued and monitored.

Asthma Around the World

Globally, asthma affects approximately 300 million people1. Of this number, 10–12% are adults and 15% are children. This rising prevalence of asthma in developing countries may be associated with urbanization. In affluent countries, patients with asthma are often found to be atopic and with allergic sensitization to house dust mites and common allergens, such as animal fur and pollen.

Asthma may present at any age, with a peak of 3 years. Thus, it is important that to educate parents of young children to be on the lookout for any alarming symptoms. Male children are twice as asthmatic as females, but this sex ratio stabilizes by adulthood. Children with asthma have been observed to become asymptomatic in adolescence and then experience a recurrence in adulthood.

The good news is that asthma severity does not vary significantly within a patient. If your patient has mild asthma, they are unlikely to progress to more severe disease. Similarly, however, patients with severe asthma usually already present with severe symptoms at the onset.

Deaths due to asthma are, thankfully, uncommon, with a steady decline in deaths over the last decade. This may be attributed to the more frequent use of inhaled corticosteroids.

Asthma Prevention

As a physician, you naturally want to provide your patients with a positive and supportive environment for discussing their concerns. New or prospective parents may have several questions on how to manage asthma. Here are some helpful tips you may recommend2:

• Do not expose children to tobacco smoke. This is applicable both during pregnancy and after birth.
• Identification and correction of vitamin D insufficiency in asthmatic pregnant people, or those planning pregnancy, may reduce the risk of early-life wheezing episodes in the children.
• Vaginal delivery should be encouraged where possible.
• Breastfeeding is advised for general health reasons.
• The use of broad-spectrum antibiotics during the first year of life should be discouraged.

The best cure is always prevention. While medications for patients who present with asthma symptoms exist, educating people on the best ways to reduce the risk of asthma before it develops will definitely go a long way.

Hyfe: Your Partner in Health Tracking

A key component of health care is monitoring. One way to help your patients monitor their symptoms is through the use of a health tracking app. Hyfe uses artificial intelligence to track cough frequency and help identify cough trends. It not only allows you to get a baseline health status of your patient when at home but also gives you insights into symptom trends. As a physician, Hyfe even allows you to access your patient’s information so that you can replay and listen to every single cough episode. As we move forward in a technologically evolving world, simple tools like Hyfe might be the start of a game-changing trend in health tracking.

Click here if you would like to learn more about asthma, treatment guidelines, or the Hyfe app.

References

1 Jameson, J., Kasper, D., Longo D., Fauci, A., Hauser, S., & Lozcalzo, J. (2015). Harrison’s Principles of Internal Medicine (19th edition).

2 Global Initiative for Asthma. (2021). Global Strategy for Asthma Management and Prevention. Accessed on 24 April 2022 from https://ginasthma.org/wp-content/uploads/2021/05/GINA-Main-Report-2021-V2-WMS.pdf