About This Page
This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
The Bottom Line
- Asthma is recurrent reversible airflow obstruction with airway inflammation and hyperresponsiveness
- Diagnosis in children old enough to test is supported by spirometry showing obstruction with bronchodilator reversibility
- Persistent asthma requires controller therapy, usually inhaled corticosteroid-based treatment
- Acute exacerbation: inhaled albuterol, ipratropium for moderate/severe exacerbation, systemic corticosteroids, oxygen, and magnesium/intubation for life-threatening disease
- NAEPP 2020 updates support intermittent ICS strategies in selected young children and ICS-formoterol SMART therapy for selected older children/adolescents
Overview
Pediatric asthma is common and heterogeneous. Children may present with wheeze, chronic cough, exercise symptoms, nighttime symptoms, or recurrent exacerbations triggered by viral infections, allergens, smoke, exercise, cold air, or pollution. Management requires assessing both severity and control, optimizing inhaler technique and adherence, reducing triggers, and escalating or stepping down therapy based on symptoms and exacerbation risk.
Epidemiology
Asthma is among the most common chronic diseases of childhood in the United States and a major cause of ED visits, hospitalizations, and school absence. Risk factors include atopy, eczema, allergic rhinitis, family history, prematurity, tobacco smoke exposure, air pollution, obesity, and viral wheezing illnesses. Disparities in morbidity and mortality are substantial.
Clinical Features
Symptoms
Episodic wheeze, cough, chest tightness, or dyspnea
Nighttime cough or symptoms with exercise, cold air, allergens, or viral infections
Frequent albuterol use, activity limitation, or school absence
Severe dyspnea, inability to speak full sentences, cyanosis, or exhaustion
Cough/wheeze with poor growth, clubbing, recurrent pneumonia, or neonatal onset suggests alternative diagnosis
Signs
Expiratory wheeze and prolonged expiratory phase
Accessory muscle use, retractions, tachypnea, or pulsus paradoxus in exacerbation
Silent chest, altered mental status, bradycardia, or hypoxemia = impending respiratory failure
Eczema, allergic rhinitis, or nasal polyps may suggest atopic disease
Focal wheeze or asymmetric breath sounds suggests foreign body
Investigations
First-line
Spirometry with bronchodilator responseFor children usually >=5 years: obstructive pattern with improvement in FEV1 after albuterol supports asthma
Clinical assessment of controlDaytime symptoms, nighttime awakenings, SABA use, activity limitation, lung function, and exacerbation history
Inhaler technique/adherence reviewEssential before stepping up therapy
Pulse oximetry in exacerbationAssess severity and need for oxygen/escalation
Second-line
Peak expiratory flowUseful for monitoring in selected older children but less diagnostic than spirometry
Allergy evaluationWhen allergic triggers are suspected or symptoms are persistent
Chest X-rayNot routine; consider focal findings, fever, first severe episode, foreign body, or poor response
Specialist
Pulmonology/allergySevere asthma, frequent systemic steroids, ICU admission, uncertain diagnosis, biologic consideration, or poor control despite medium/high-dose therapy
PICUImpending respiratory failure, continuous albuterol requirement with exhaustion, altered mental status, or need for ventilatory support
1
Long-term control
- Intermittent asthma may use reliever therapy; persistent asthma requires inhaled corticosteroid-based controller treatment
- Assess control at each visit and step up if uncontrolled after checking technique, adherence, triggers, and comorbidities
- Step down after sustained good control, usually at least 3 months, to lowest effective regimen
- Written asthma action plan and spacer use are high-yield pediatric interventions
2
Controller strategies
- Daily low-dose inhaled corticosteroid is classic first-line controller for persistent asthma
- Selected young children with viral-triggered recurrent wheeze may use intermittent high-dose ICS at onset of respiratory tract infection per guideline criteria
- ICS-formoterol single maintenance and reliever therapy can be used in selected children/adolescents at appropriate steps and ages
- Leukotriene receptor antagonists are alternatives/add-ons but are generally less effective than ICS and require neuropsychiatric caution
3
Acute exacerbation
- Albuterol by MDI/spacer or nebulizer; repeat frequently or continuous for severe exacerbation
- Add ipratropium for moderate to severe ED exacerbations
- Systemic corticosteroids for moderate/severe exacerbations or inadequate response to initial bronchodilator
- Oxygen to maintain adequate saturation; IV magnesium sulfate for severe exacerbation not responding to initial therapy
4
Trigger and comorbidity management
- Avoid tobacco smoke exposure, address allergens when sensitized, treat allergic rhinitis, and encourage influenza vaccination
- Exercise-induced symptoms: pre-exercise albuterol and optimized controller therapy if frequent
- Obesity, GERD, sleep-disordered breathing, and anxiety may worsen symptoms but should not distract from airway inflammation control
Complications
- Status asthmaticus: Severe exacerbation refractory to initial bronchodilators with risk of respiratory failure
- Airway remodeling: Poorly controlled chronic inflammation can reduce lung function over time
- Medication adverse effects: ICS can slightly affect growth velocity; systemic steroids cause broader adverse effects, so control should minimize bursts
- School/activity limitation: Poor control leads to absenteeism and reduced exercise tolerance
- Misdiagnosis: Foreign body, cystic fibrosis, aspiration, vocal cord dysfunction, and cardiac disease can mimic wheeze
USMLE Step 2 CK Exam Tips
- 1Persistent asthma = inhaled corticosteroid controller, not albuterol alone
- 2Before stepping up therapy, check inhaler technique and adherence
- 3Acute severe asthma: albuterol + ipratropium + systemic steroids + oxygen; magnesium if poor response
- 4Silent chest is worse than wheezing — it means poor air movement
- 5Focal wheeze after choking episode = foreign body, not asthma
- 6Bronchiolitis is first-time viral wheeze in an infant; asthma is recurrent reversible episodes
- 7SMART therapy uses ICS-formoterol because formoterol has rapid onset; do not use salmeterol as rescue
- 8Nighttime symptoms and exercise limitation indicate poor control
practicetest your knowledge on pediatric asthmaApply what you've learnt with USMLE Step 2 CK-style questions from the iatroX Q-Bank — pediatrics and beyond.
open q-bank