Pediatric Asthma Overview
A Modern Clinical Guide to Diagnosis & Management
Pathophysiology
Understand inflammatory mechanisms
Clinical Presentation
Recognize signs, symptoms, & triggers
Diagnostic Approach
Apply evidence-based strategies
Differential Diagnosis
Distinguish asthma from mimics
Chronic airway inflammation with hyperresponsiveness
Airways become sensitive to environmental triggers
Cellular Components
Mast Cells
Release histamine
Eosinophils
Key inflammatory cells
T Lymphocytes
Coordinate immune response
Neutrophils
Present in severe asthma
Inflammatory Mediators
Histamine
Bronchoconstriction
Leukotrienes
Potent bronchoconstrictors
Bradykinin
Vascular permeability
Cytokines
Inflammatory response
Clinical Significance
The Pathophysiological Result
The interplay of these cellular components and inflammatory mediators results in heightened airway sensitivity. This leads to the classic triad of asthma symptoms:
Bronchospasm & Wheezing
Inflammation & Coughing
Mucus & Dyspnea
Global Impact
Disease Burden & Statistics
Most common chronic childhood disease with significant global health burden
Demographics
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Gender Distribution
Higher prevalence in boys during childhood
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Geographic Pattern
Urban areas show higher prevalence than rural
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Trending Upward
Global prevalence continues to increase
Key Symptoms
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Coughing
Often worse at night or with triggers.
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Wheezing
High-pitched sound, especially on exhalation.
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Shortness of Breath (Dyspnea)
Difficulty breathing, feeling of not getting enough air.
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Exercise Intolerance
Coughing or wheezing during or after physical activity.
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Chest Tightness
A sensation of squeezing or pressure in the chest.
Assess the frequency, severity, and precipitating factors of symptoms, along with a family history of asthma and allergies.
Common Exacerbating Factors
Viral Infections
Allergens
Irritants (Smoke)
Exercise
Emotions
Weather Changes
Associated Conditions
Nocturnal Symptoms
Rhinosinusitis
Gastroesophageal Reflux
Aspirin Sensitivity
Physical Examination & Acute Assessment
Identifying signs of an asthma exacerbation
Physical Examination
Findings in Acute Episodes
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Tachypnea (Increased respiratory rate)
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Tachycardia (Elevated heart rate)
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Cough
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Wheezing
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Prolonged expiratory phase
Signs of a Progressing Attack (Severe)
IMMEDIATE ATTENTION REQUIRED
Cyanosis
Diminished Air Movement
Retractions
Agitation
Inability to Speak
Tripod Position
Diaphoresis
Pulsus Paradoxus
Associated Atopic Findings
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Eczema
Atopic dermatitis, often on skin flexures.
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Allergic Rhinitis
Nasal congestion, sneezing, "allergic shiners".
Clinical Diagnosis
Evidence-Based Strategy
Combined clinical assessment with objective measurements - No single definitive test
Spirometry (Gold Standard)
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Age Requirement
Children >5 years old
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Key Measurements
FEV1, FVC, FEV1/FVC ratio
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Reversibility Test
>12% & 200mL improvement
Peak Flow Monitoring
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Home Assessment
Daily monitoring capability
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Diurnal Variation
>20% suggests asthma
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Limitation
Not for initial diagnosis
Chest X-ray
Indications
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First episode of asthma.
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Recurrent episodes of undiagnosed cough or wheeze.
Purpose & Limitations
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Exclude anatomic abnormalities.
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Not needed for repeat episodes unless fever or localized findings are present.
Exhaled Nitric Oxide (FeNO)
Reflects eosinophilic airway inflammation
Clinical Utility
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Identifies patients likely to respond well to corticosteroids.
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Aids in monitoring therapy response and optimizing dosage.
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Helps detect nonadherence to corticosteroid therapy.
Allergy Testing
Should be part of the evaluation for all children with persistent asthma, but NOT during an acute exacerbation. Its purpose is to identify sensitization to common aeroallergens (pollens, mold, dust mite, pet dander).
Comparison of Methods
Skin Testing
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Results in minutes
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More sensitive
In Vitro Serum Tests (ELISA)
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Less sensitive
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More expensive
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Takes several days for results
⚠️ Critical Principle
Not all that wheezes is asthma. A systematic differential diagnosis is essential for accurate diagnosis and appropriate treatment planning.
Differential Diagnosis of Cough & Wheeze
In Infants and Children
Upper Airway Diseases
Allergic rhinitis
Sinusitis
Large Airway Obstruction
Tracheal or bronchial foreign body
Paradoxical vocal fold motion
Vascular rings or laryngeal webs
Enlarged lymph nodes or tumor
Small Airway Obstruction
Viral bronchiolitis or obliterative bronchiolitis
Cystic fibrosis
Bronchopulmonary dysplasia
Other
Recurrent cough not caused by asthma (infection, habit cough, postnasal drip)
Aspiration from swallowing dysfunction or GERD
Heart failure, pulmonary edema
Infant Considerations
Age-Specific Approach
For persistent cough in the first few months of life, consider specific conditions using the CRADLE mnemonic.
Clinical Importance
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Systematic Evaluation
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Age-Appropriate Diagnosis
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Early Intervention
Aspergillosis Note
Allergic bronchopulmonary aspergillosis is a hypersensitivity reaction to antigens of the mold Aspergillus fumigatus. It occurs primarily in patients with steroid-dependent asthma and in patients with cystic fibrosis.
CRADLE Mnemonic
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C
Cystic fibrosis
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R
Respiratory tract infections
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A
Aspiration
Swallowing dysfunction, GERD, tracheoesophageal fistula, foreign body
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D
Dyskinetic cilia
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L
Lung and airway malformations
Laryngeal webs, laryngotracheomalacia, tracheal stenosis, vascular rings and slings
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E
Edema
Heart failure, congenital heart disease
Take-Home Messages
Key Principles in Pediatric Asthma
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Asthma is a Clinical Diagnosis
Diagnosis relies on a pattern of symptoms, physical examination, and objective tests like spirometry. There is no single definitive test.
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Not All That Wheezes is Asthma
A broad differential diagnosis is critical, especially in young children and infants. Consider conditions from infections to anatomical abnormalities.
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Assess Severity in Acute Events
Promptly identify signs of severe or life-threatening exacerbations (e.g., retractions, speech difficulty) to guide immediate intervention.
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Age-Specific Approaches are Key
The presentation, triggers, and differential diagnosis vary with age. Tailor your evaluation for infants, toddlers, and older children.