What is Childhood Asthma?
Asthma is a condition that affects the airways and the small tubes that carry air in and out of the lungs. Childhood asthma is not a different disease than asthma in adults, but children face bothersome symptoms that interfere with their daily activities including play, sports, school and sleep.
The word ‘asthma’ is derived from a Greek word meaning 'breathlessness or panting' both of which accurately describe an attack of asthma.
In children with asthma, airways are swollen and inflamed. When these inflamed airways come into contact with an asthma trigger, symptoms of asthma appear.
Asthma has multiple causes, and two or more different causes can be present in one child. Colds and allergens are the two most common factors that trigger an asthma attack. Coughing, recurrent bronchitis, wheezing and shortness of breath, especially during exercising can be seen in an asthmatic child.
Based on the severity of the symptoms, childhood asthma can be classified as:
- Mild - Cough or a wheeze is present, but the child plays happily and feeds well. Sleep is undisturbed by symptoms.
- Moderate - The child wakes up at night and cannot run around and play without wheezing or cough.
- Severe - The child is too restless to sleep, unwilling to play at all, too breathless to talk or feed.
There is no particular diagnostic test and asthma is diagnosed with the help of medical history, symptom evaluation and physical examination.
Asthma cannot be cured and symptoms may continue into adulthood. But symptoms can be kept under control with the right treatment, which involves preventing the asthma symptoms and treating an asthma attack in progress.
- Asthma is the third leading cause of hospitalization in children under age 15.
- India contributes to 10% of the global burden of asthma, with around 24 million of its population being asthmatic.
- Asthma prevalence is higher in children (9.4 percent) than in adults (7.7 percent), and higher in females (9.2 percent) than in males (7.0 percent).
- It is estimated that more than 100 million people will be affected with asthma by 2025.
- World Asthma Day is commemorated every year on the first Tuesday of May.
- It occurs due to allergens, which cause inflammation and narrowing of tubes in the airways resulting in shortness of breath. The secretions produced due to inflammation are trapped within air tubes causing wheezing and cough.
- Genetic factors also play a role, for example a person having a blood relative with asthma has a higher chance of developing it.
- Smoking during pregnancy can make the baby more vulnerable to asthma.
- A baby born by C-section is said to be more prone to develop asthma, as they are not exposed to the bacterial flora of the vagina during birth, which strengthens their immunity.
- Air pollution and pollen.
- Frequent childhood airway infections.
These causes of asthma are not fully understood but developing an overly sensitive immune system generally plays a role. Due to increased immune system sensitivity, the lungs and airways become swollen and produce mucus when exposed to certain triggers.
The triggering factors of asthma include:
- Cold or flu (viral infection)
- Car fumes
- Paint fumes
- Exercise (especially on a cold dry day)
- Furry feathery animals/ pets/ toys
- House dust mite (beds, carpets, soft toys)
When a person comes in contact with an asthma trigger, the muscles around the walls of the airways tighten so that the airway becomes narrower. The lining of the airway swells and produces sticky mucus. As the airways narrow, it becomes difficult for air to move in and out and they find it difficult to breath. This may be accompanied by a wheezing or whistling noise.
Depending on the trigger there are two types of asthma. Extrinsic asthma is an immune response to an external allergen such as pollen or dust. Intrinsic asthma is due to inhaling certain chemical agents such as cigarette smoke and paint vapors.
- Family history of allergies and asthma
- Low birth weight
- Winter birth - Children born in the winter have an increased risk of developing asthma
- Gender - Asthma develops more frequently in boys than girls but after puberty it is more common in girls
- Exposure to maternal smoking in the womb
- Underperformance or absence in school
- Respiratory failure
- Status asthmaticus - asthma does not respond to treatment
- Growth delay
- Risk of learning disabilities
- Frequent coughing spells (during play, at night, or while laughing)
- Wheezing (whistling sound from the chest while breathing)
- Rapid breathing
- Chest tightness
- Chest pain
- Shortness of breath, especially during exercise
- Dark circles under the eyes
- Loss of appetite
- Trouble sleeping due to shortness of breath, coughing or wheezing
- Fatigue due to inadequate sleep
Childhood asthma is difficult to diagnose during infancy. Observe for indicators in your infant like audible wheezing, pale or bluish skin, and rapid breathing. Also note if they are irritable and keep sitting and also refuse to lie down.
Asthma in older children can be detected by -
Medical history - A family history of asthma, allergies, eczema, or other lung disease increases the chances of developing asthma.
Symptom evaluation - A detailed description about the symptoms (difficulty breathing, chest pain, wheezing or shortness of breath) by the parents can help the doctor to diagnose childhood asthma.
Physical examination - Auscultation of the heart and lungs to listen to any abnormal chest sounds helps in the diagnosis.
Pulmonary function tests (PFTs) are a collective group of tests that measure the amount of air in the lungs and how fast it can be exhaled. The results help the doctor determine the severity of the asthma. Pulmonary function tests cannot be performed in children younger than 5 years and in such cases the doctors have to rely on history, symptoms and examination in making the diagnosis. PFTs confirm the presence of asthma in the patient.
Spirometry - The patient will be asked to breathe into a mouthpiece that is connected to a device called a spirometer. It will measure the amount of air that they can breathe in and out and its rate of flow.
Peak flow test - It is used to measure how fast you can breathe out air from your lungs into a device called the peak flow meter.
Exhaled nitric oxide test - It measures the level of nitric oxide in your breath. The level of nitric oxide in the breath indicates the level of inflammation of the airways.
Methacholine challenge - Methacholine is an asthma trigger, which when inhaled can cause constriction of the airways. Thus, if the patient reacts to methacholine, they are likely to have asthma.
Histologic findings - Eosinophilic infiltration is considered a major marker of asthma. Histological findings reveal narrowing of airway lumina, bronchial and bronchiolar epithelial denudation and mucus plugs. Patients with severe asthma have smooth muscle hypertrophy and a thickened basement membrane.
Allergy skin test - The doctor advises an allergy skin test if the child has asthma that is triggered by allergies. This test helps identify whether the child is allergic to pollen, mold, dust mites or other allergens.
The most important part in managing asthma is developing a better understanding about how and when asthma causes problems, how to avoid the triggering factors and how to use the asthma medication. The doctor outlines an ‘asthma action plan’ for the parent that indicates the medications to be taken, when and how to increase the doses or add more medication if needed and when to seek emergency care for the child.
Treating asthma involves preventing the asthma symptoms and treating an asthma attack in progress.
Asthma medications can be classified as:
- Quick relief medications (inhaled rescue medications) - These medicines open swollen airways that are limiting breathing. Rescue inhalers help to relieve breathing difficulties during an asthma flare-up. This inhaler eases the symptoms right away
- Short acting beta-agonists such as Salbutamol
- Long-term asthma control medications (inhaled and oral medicines) - Control inflammation that commonly causes the asthma. Preventer inhalers help protect airways. They make asthma symptoms less likely. Long-term control medications such as inhaled corticosteroids keep asthma under control on a day-to-day basis and make an asthma attack less likely
- Inhaled medicines: Medicines can be inhaled with the help of:
- Pressurized metered-dose inhalers (pumps)
- Nebulizer solutions (delivered as a mist by a machine)
- Dry powder inhalers
Most children with persistent asthma need to use a combination of long-term control medications and quick-relief medications. Some children may require medications to treat allergies.
Most asthma medications that are given to adults can also safely be prescribed to children with asthma after adjusting the doses for their age and weight.
- Avoid triggering factors like dust mite, furry toys, pets, pollen, smoke, dust mite and carpets. Exposure to irritants may make your airways more reactive to substances in the air. Keeping your home free from these triggers can help prevent asthma attacks. Cockroaches carry a protein that acts as an allergen that can trigger asthma attacks in people.
- Keep active - Exercise is the best way to keep one's body in the right condition. However exercise is also a common asthma trigger. But that does not mean that you should stop. The exercise tolerance improves with time.
- Avoid smoking
- Childhood Asthma - Overview - (http://acaai.org/asthma/who-has-asthma/children)
Latest Publications and Research on Childhood AsthmaThe impact of fetal umbilical artery Doppler pulsatility index on childhood respiratory function and atopy - A prospective case-control study. - Published by PubMed
Environmental grass pollen levels in utero and at birth and cord blood IgE: Analysis of three birth cohorts. - Published by PubMed
2-Naphthol Levels and Allergic Disorders in Children. - Published by PubMed
Evaluation of prooxidant-antioxidant balance in in vitro fertilization-conceived mice. - Published by PubMed
The future outlook on allergen immunotherapy in children: 2018 and beyond. - Published by PubMed