Asthma in Children: Causes, Diagnosis, and Management
Asthma in children is a chronic inflammatory airway disease characterized by recurrent episodes of wheezing, shortness of breath, and coughing, often worse at night. It involves intermittent and reversible airway obstruction due to bronchial hyperresponsiveness and chronic inflammation. Effective management requires long-term controller therapy, primarily inhaled corticosteroids, combined with trigger avoidance and a personalized action plan.
Key Takeaways
Asthma is chronic airway inflammation causing reversible obstruction.
Key features include wheezing, cough, and chest tightness.
Etiology is multifactorial, involving genetics and allergen exposure.
Inhaled corticosteroids are the primary long-term controller drug.
Management requires an action plan and strict trigger avoidance.
What is Asthma in Children, and how common is it?
Pediatric asthma is defined as a chronic inflammatory condition of the airways, leading to recurrent episodes of wheezing, dyspnea, chest tightness, and coughing. The defining characteristics are intermittent and reversible airway obstruction, driven by chronic inflammation and bronchial hyperresponsiveness to various stimuli. Globally, asthma affects a significant portion of the pediatric population, with prevalence rates varying by region, such as 8.4% in US children and 4.5% reported in Indonesia (Riskesdas 2018).
- Chronic inflammation of airways (recurrent episodes of wheezing, dyspnea, chest tightness, cough).
- Key Features: Intermittent and Reversible Airway Obstruction.
- Global Prevalence (e.g., US: 8.4% in children).
- Indonesia Prevalence (e.g., Riskesdas 2018: 4.5%).
What causes pediatric asthma, and what are the main risk factors?
The etiology of asthma is multifactorial, resulting from a complex interaction between genetic predisposition and environmental triggers. Key causes include genetic factors like atopy and IgE production, exposure to common allergens such as dust mites and pollen, and viral infections like RSV and Rhinovirus. Non-allergen factors like cold air, exercise, and stress can also trigger symptoms. The strongest risk factor is atopy/allergy, followed by a family history of asthma, which increases risk 3-6 times.
- Etiology (Multifactorial): Genetic/Atopy, Allergen Exposure, Viral Infections, Non-Allergen Factors.
- Family history (3-6x increased risk).
- Atopy/Allergy (Strongest risk factor).
- Smoking Exposure (Prenatal and postnatal).
- Perinatal/Nutrition (C-section, low exclusive breastfeeding, early obesity).
How does asthma develop in the body (Pathogenesis and Pathophysiology)?
Asthma pathogenesis begins with an immune response, typically involving the activation of the Th2 response, which releases cytokines like IL-4 and IL-13. This leads to IgE production and the activation of mast cells and basophils, resulting in the release of inflammatory mediators such as histamine and leukotrienes. Physiologically, these mediators cause bronchoconstriction (an early mechanism), chronic airway inflammation (mucosal edema and cell infiltration), and bronchial hyperresponsiveness. Over time, repeated inflammation can lead to irreversible Airway Remodeling, characterized by basal membrane thickening and mucus hypersecretion.
- Pathogenesis: Th2 response activation, IgE production, Mast cell/Basophil activation, Release of Inflammatory Mediators.
- Pathophysiology: Bronchoconstriction, Chronic Airway Inflammation, Bronchial Hyperresponsiveness, Airway Remodeling.
How is pediatric asthma classified?
Pediatric asthma is classified based on several criteria to guide treatment and prognosis. Classification can be done by age group, distinguishing between infants/toddlers (under 2 years) and school-age children (5-11 years). It is also classified by symptom frequency, ranging from intermittent to persistent, which is further graded as mild, moderate, or severe. Furthermore, asthma can be categorized by phenotype, such as viral-induced, exercise-induced, or allergen-triggered, and by the current level of control achieved through treatment.
- By Age Group: Infant/Toddler (<2 years) and School Age (5-11 years).
- By Symptom Frequency: Intermittent and Persistent (Mild, Moderate, Severe).
- By Phenotype: Viral-induced, Exercise-induced, Allergen-triggered.
- By Current Control Status.
What steps are involved in diagnosing asthma in children?
Diagnosis relies heavily on a thorough history (anamnesis), focusing on key symptoms like episodic wheezing that is worse at night, identifying triggers (infections, cold air, allergens), and assessing risk factors (family history, perinatal factors). Physical examination during an attack may reveal tachypnea, retractions, and wheezing, while chronic signs include a barrel chest or atopy signs like Dennie-Morgan lines. Supporting tests include spirometry (FEV1/FVC ratio and reversibility test) and Peak Flow Meter monitoring. It is crucial to rule out differential diagnoses such as TB, bronchiolitis, foreign body aspiration, GERD, or congenital heart disease.
- Anamnesis: Key Symptoms (Episodic, worse at night), Triggers, Risk Factors.
- Physical Examination: During Attack (Tachypnea, Retractions, Wheezing), Chronic (Barrel Chest), Atopy Signs.
- Supporting Tests: Spirometry, Peak Flow Meter (PFM), Atopy Tests (Not routine).
- Differential Diagnosis: Infection/Immunologic, Mechanical Obstruction, Other Organ Systems.
What are the key strategies for managing acute and long-term pediatric asthma?
Asthma management involves treating acute exacerbations and implementing long-term control. Acute management starts with assessing severity and administering First Line Therapy, which is Short-Acting Beta Agonists (SABA) via inhalation; nebulizers are preferred for severe attacks, sometimes combined with Ipratropium. Systemic corticosteroids are used if the child does not improve. Long-term controller therapy centers on Inhaled Corticosteroids (ICS), starting at a low dose and evaluating effectiveness every 6-8 weeks. Non-medical management includes patient education, strict trigger avoidance, and utilizing a written Asthma Action Plan for stable periods and severe attacks.
- Acute Exacerbation Management: Initial Assessment, First Line Therapy (SABA via inhalation), Systemic Corticosteroids.
- Long-Term Controller Therapy: Primary Drug (Inhaled Corticosteroids), Principle (Start low dose, evaluate 6-8 weeks), Step-Up Adjustments.
- Non-Medical Management & Prevention: Education, Trigger Avoidance, Asthma Action Plan.
Which inhalation devices are used for treating pediatric asthma?
Several devices are used to deliver asthma medication, each with specific advantages and limitations depending on the child's age and coordination ability. Nebulizers are excellent for acute attacks and young children as they require no coordination, though they require electricity and have low lung deposition. Metered Dose Inhalers (MDI) require coordination, but using an MDI with a Spacer significantly reduces local side effects and improves drug delivery. Dry Powder Inhalers (DPI) require no coordination but are unsuitable for children under 5 years old because they demand a strong, forceful inspiration.
- Nebulizer: Pros (No coordination needed, good for acute/young children), Cons (Requires electricity, low lung deposition (~12%)).
- MDI (Metered Dose Inhaler): Cons (Requires coordination between actuation and inhalation).
- MDI + Spacer: Reduces local side effects and improves delivery.
- DPI (Dry Powder Inhaler): Pros (No coordination needed), Cons (Not suitable for children < 5 years).
Frequently Asked Questions
What are the key features that define pediatric asthma?
Asthma is defined by chronic inflammation of the airways and key features include recurrent episodes of wheezing, cough, and chest tightness. Crucially, it involves intermittent and reversible airway obstruction and bronchial hyperresponsiveness.
What is the strongest risk factor for developing asthma in children?
The strongest risk factor identified for pediatric asthma is atopy or allergy. Other significant factors include a family history of asthma, exposure to smoking (prenatal and postnatal), and certain perinatal factors like early obesity or low exclusive breastfeeding.
What is the primary drug used for long-term asthma control?
The primary drug for long-term controller therapy is Inhaled Corticosteroids (ICS), such as Budesonide. The principle of treatment is to start with a low dose and evaluate the child's response and control status every six to eight weeks.
Why is using a spacer recommended with a Metered Dose Inhaler (MDI)?
Using a spacer with an MDI is recommended because it significantly reduces local side effects, such as oral thrush, and improves the overall delivery and deposition of the medication into the child's lungs, making the treatment more effective.
What are the main differential diagnoses that must be considered when diagnosing asthma?
Differential diagnoses include infectious or immunologic conditions like TB or bronchiolitis, mechanical obstructions such as foreign body aspiration, and issues related to other organ systems, including GERD (Gastroesophageal Reflux Disease) or congenital heart disease.
