Overview
Definition:
Asthma step therapy is a structured approach to asthma management that involves adjusting medication intensity based on symptom control and exacerbation frequency, following established guidelines like those from the Global Initiative for Asthma (GINA)
This stepwise approach aims to achieve and maintain asthma control with the least amount of medication necessary, minimizing side effects and optimizing patient outcomes.
Epidemiology:
Asthma is the most common chronic respiratory disease in children, affecting approximately 10-15% of school-age children globally
In India, prevalence rates vary regionally but are significant, leading to substantial healthcare burden, school absenteeism, and reduced quality of life
Boys are generally more affected than girls in younger age groups, with this trend reversing in adulthood.
Clinical Significance:
Effective step therapy is crucial for preventing irreversible airway remodeling, reducing the frequency and severity of exacerbations, and improving lung function in school-age children
Poorly controlled asthma can lead to developmental delays, impaired physical activity, sleep disturbances, and significant emergency room visits and hospitalizations, impacting a child's overall well-being and academic performance
This knowledge is vital for DNB and NEET SS preparation.
Clinical Presentation
Symptoms:
Wheezing, often expiratory
Shortness of breath
Chest tightness
Cough, particularly nocturnal or exercise-induced
Symptoms are often intermittent and variable, worsening with triggers like allergens, infections, or exercise.
Signs:
Audible wheezing on auscultation
Tachypnea
Use of accessory respiratory muscles
Prolonged expiratory phase
In severe exacerbations, decreased breath sounds, cyanosis, and altered mental status may be present
Physical examination may also reveal signs of atopy, such as eczema or allergic rhinitis.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on recurrent symptoms of airflow obstruction and variability
Objective confirmation can be achieved with spirometry showing reversible airflow obstruction (significant improvement in FEV1 or FVC after bronchodilator administration)
While not standard in young children, impulse oscillometry or bronchial provocation tests can be used
GINA guidelines provide a framework for assessing symptom control and asthma severity.
Diagnostic Approach
History Taking:
Detailed history of symptom frequency, severity, and triggers
Nocturnal awakenings
Impact on daily activities and school attendance
History of atopy (eczema, allergic rhinitis, food allergies)
Family history of asthma or atopy
Previous treatments and their effectiveness
Red flags include persistent symptoms, rapid progression, or failure to respond to initial treatment.
Physical Examination:
Assess respiratory rate, work of breathing, and oxygen saturation
Auscultate for wheezing, rhonchi, and diminished breath sounds
Examine for signs of atopy
Evaluate for other potential causes of cough or dyspnea.
Investigations:
Spirometry with bronchodilator response (FEV1, FVC, FEV1/FVC ratio)
Peak expiratory flow rate (PEFR) monitoring
Allergy testing (skin prick or IgE) to identify specific triggers may be considered
Chest X-ray to rule out other conditions if diagnosis is uncertain or atypical presentation
Blood eosinophil count can be indicative of eosinophilic airway inflammation.
Differential Diagnosis:
Bronchiolitis, pneumonia, foreign body aspiration, cystic fibrosis, vocal cord dysfunction, upper airway obstruction, gastroesophageal reflux disease (GERD), congenital anomalies, psychogenic cough.
Management
Initial Management:
Education on asthma, trigger avoidance, and proper inhaler technique
Provision of a reliever inhaler (short-acting beta-agonist - SABA)
Development of an asthma action plan.
Medical Management:
Stepwise therapy based on GINA guidelines: Step 1: SABA as needed
Step 2: Low-dose inhaled corticosteroid (ICS) daily OR as-needed low-dose ICS-formoterol (preferred)
Step 3: Medium-dose ICS daily OR low-dose ICS-formoterol as-needed PLUS a long-acting beta-agonist (LABA)
Step 4: Medium-dose ICS-LABA OR high-dose ICS-LABA
Step 5: Add-on therapies like LTRA, tiotropium, or biologics for severe, uncontrolled asthma
Dosing for ICS: Budesonide, Fluticasone propionate, Beclomethasone dipropionate
Typical low dose: 100-200 mcg/day
Medium dose: 200-400 mcg/day
High dose: >400 mcg/day.
Surgical Management:
Generally not applicable for standard asthma management in school-age children
Surgical interventions may be considered for specific complications or co-existing conditions, but not for the asthma itself.
Supportive Care:
Regular follow-up appointments to assess symptom control and adherence
Nutritional assessment
Support for school attendance and physical activity participation
Psychosocial support for the child and family.
Complications
Early Complications:
Asthma exacerbations (acute worsening of symptoms), leading to respiratory distress, hospitalization, and ICU admission
Pneumothorax, rare but serious
Status asthmaticus.
Late Complications:
Airway remodeling (irreversible narrowing of airways) leading to persistent airflow limitation
Chronic cough
Growth impairment (though often related to steroid use, not asthma itself)
Psychological impact including anxiety and depression.
Prevention Strategies:
Adherence to prescribed step-up/step-down therapy
Regular review of asthma control
Prompt treatment of exacerbations
Strict avoidance of identified triggers
Education on correct inhaler technique and action plans.
Prognosis
Factors Affecting Prognosis:
Age of onset (earlier onset often associated with persistent asthma)
Severity of asthma
Presence of atopy
Adherence to treatment
Genetic factors
Environmental exposures
Quality of asthma education and management plan.
Outcomes:
With appropriate step therapy and adherence, most children achieve good asthma control, leading to a normal or near-normal quality of life, reduced exacerbations, and preserved lung function
Some children may outgrow their asthma, while others may have persistent symptoms into adulthood.
Follow Up:
Regular follow-up (every 3-12 months depending on control level) is essential to reassess control, adjust therapy, review inhaler technique, and update the asthma action plan
Education about recognizing worsening symptoms and seeking timely medical attention.
Key Points
Exam Focus:
GINA stepwise approach to asthma management in children
Differentiating asthma from other respiratory conditions
Recognizing and managing asthma exacerbations
Principles of inhaled corticosteroid and bronchodilator therapy
Role of objective lung function tests.
Clinical Pearls:
Always assess symptom control before adjusting therapy
Step down therapy when control is maintained for at least 3 months
Emphasize proper inhaler technique with a spacer
Educate parents and children on individualized asthma action plans
Consider comorbidities like allergic rhinitis and GERD
The preferred reliever therapy in current GINA guidelines is as-needed low-dose ICS-formoterol for Steps 2 and 3.
Common Mistakes:
Over-reliance on SABAs alone without ICS
Incorrect diagnosis due to failure to consider differential diagnoses
Poor adherence to ICS due to perceived side effects or lack of perceived benefit
Incorrect inhaler technique leading to ineffective treatment
Inadequate education on asthma action plans
Failure to step down therapy when control is achieved.