One-liner#

Asthma management centers on inhaled corticosteroids as the foundation of therapy, GINA step-based escalation guided by symptom control and exacerbation risk, trigger avoidance, and ensuring every patient has a written action plan for worsening symptoms.

Quick nav#

• Definition and epidemiology
• Pathophysiology
• Clinical presentation
• Diagnostic workup
• Treatment
• Patient education
• Prognosis and monitoring
• Special populations
• When to refer
• Smartphrase snippets
• Related pages

Definition and epidemiology#

Diagnostic criteria#

Asthma is defined by variable respiratory symptoms (wheeze, shortness of breath, chest tightness, cough) AND variable expiratory airflow limitation, confirmed by objective testing.

Diagnostic confirmation requires BOTH:

1. History of variable respiratory symptoms (worse at night/early morning, triggered by exercise/allergens/irritants/viral infections)
2. Documented variable expiratory airflow limitation:
   • Positive bronchodilator reversibility: FEV1 increase ≥12% AND ≥200 mL from baseline
   • Excessive variability in twice-daily PEF over 2 weeks: average daily diurnal variability >10%
   • Significant increase in FEV1 after 4 weeks of anti-inflammatory treatment
   • Positive bronchial challenge test (methacholine PC20 <4 mg/mL)

Severity classification (at initial diagnosis, before treatment):

• Intermittent: symptoms ≤2 days/week, nighttime awakenings ≤2x/month, FEV1 >80%
• Mild persistent: symptoms >2 days/week but not daily, nighttime awakenings 3-4x/month, FEV1 ≥80%
• Moderate persistent: daily symptoms, nighttime awakenings >1x/week, FEV1 60-80%
• Severe persistent: symptoms throughout day, nighttime awakenings often nightly, FEV1 <60%

Control assessment (once on treatment):

• Well-controlled: symptoms ≤2 days/week, no nighttime awakenings, no activity limitation
• Not well-controlled: symptoms >2 days/week, any nighttime awakenings, any activity limitation
• Very poorly controlled: symptoms throughout day, nighttime awakenings ≥4x/week

Epidemiology#

Prevalence is approximately 8% of US adults (25 million Americans). More common in women after puberty. Risk factors include atopy/allergies (strongest), family history, childhood respiratory infections, obesity, occupational exposures, and tobacco smoke exposure. African American and Puerto Rican populations have higher prevalence and worse outcomes. Asthma causes approximately 3,500 deaths annually in the US—most are preventable with proper management.

Pathophysiology#

Mechanism (clinical understanding)#

Asthma is a chronic inflammatory airway disease characterized by three key features:

Airway inflammation (the core problem):

• Th2-mediated immune response with eosinophils, mast cells, and IgE
• Inflammatory mediators cause bronchoconstriction and mucus production
• Eosinophilic inflammation responds well to corticosteroids
• This is why ICS is the foundation of therapy

Airway hyperresponsiveness:

• Airways overreact to triggers (allergens, irritants, cold air, exercise, viral infections)
• Smooth muscle contracts excessively, causing bronchoconstriction
• Beta-agonists relax smooth muscle but don’t address inflammation

Reversible airflow obstruction:

• Unlike COPD, airflow limitation in asthma is largely reversible
• With treatment, lung function can return to normal
• Chronic uncontrolled inflammation leads to airway remodeling (irreversible)

Key distinction from COPD: Asthma has eosinophilic inflammation and reversible obstruction; COPD has neutrophilic inflammation and fixed obstruction.

How to explain to patients#

Your airways are like tubes that carry air in and out of your lungs. In asthma, these tubes are swollen and the muscles around them are twitchy—they squeeze too easily.

Think of it like a garden hose. If the hose is swollen on the inside and someone keeps squeezing it, less water gets through. That’s what happens during an asthma attack—less air gets through.

We use two types of medicines: controllers that reduce the swelling every day, and relievers that relax the muscles when you have symptoms. The controller medicine is most important—it prevents attacks.

Clinical presentation#

Characteristic symptoms#

Classic symptom pattern:

• Wheeze: high-pitched whistling sound, especially on exhalation
• Shortness of breath: often episodic, worse with triggers
• Chest tightness: described as “band around chest”
• Cough: often dry, worse at night or early morning

Temporal patterns (key diagnostic clue):

• Symptoms vary over time and in intensity
• Worse at night and early morning
• Triggered by specific exposures (allergens, exercise, cold air, irritants)
• Improve with bronchodilators or spontaneously

Common triggers:

• Allergens: dust mites, pet dander, mold, pollen, cockroach
• Irritants: tobacco smoke, strong odors, air pollution
• Exercise, cold air, viral respiratory infections
• Medications: NSAIDs, beta-blockers (in susceptible patients)
• GERD (can trigger or worsen asthma)

Physical exam findings#

Between exacerbations (may be normal):

• Exam often completely normal when well-controlled
• Mild end-expiratory wheeze may be present
• Signs of allergic rhinitis (pale, boggy turbinates)

During exacerbation:

• Diffuse expiratory wheezing
• Prolonged expiratory phase
• Tachypnea, tachycardia
• Use of accessory muscles
• Inability to speak in full sentences

Severe exacerbation (impending respiratory failure):

• Silent chest (no air movement—ominous sign)
• Cyanosis, altered mental status
• Paradoxical breathing

Red flags#

Require urgent evaluation or ED referral:

• SpO2 <92% on room air
• Unable to speak in full sentences
• Accessory muscle use, tripod positioning
• Peak flow <50% of personal best
• Altered mental status
• Silent chest despite respiratory distress
• Previous near-fatal asthma (intubation, ICU)
• Symptoms not responding to rescue inhaler

Diagnostic workup#

Initial evaluation#

Spirometry with bronchodilator reversibility (essential for diagnosis):

• Pre- and post-bronchodilator FEV1, FVC, FEV1/FVC ratio
• Administer SABA (albuterol 400 mcg via MDI with spacer)
• Repeat spirometry 10-15 minutes later
• Positive reversibility: FEV1 increase ≥12% AND ≥200 mL
• Normal spirometry does not exclude asthma (test when symptomatic if possible)

Peak expiratory flow (PEF) monitoring:

• Measure twice daily for 2 weeks if spirometry unavailable or normal
• Variability >10% supports asthma diagnosis
• Also useful for ongoing monitoring and action plans

Allergy testing (if allergic triggers suspected):

• Skin prick testing (preferred) or serum specific IgE
• Test for common aeroallergens: dust mites, cat, dog, mold, cockroach, pollens
• Guides allergen avoidance and consideration for immunotherapy

Basic labs:

• CBC with differential: eosinophilia (>300 cells/μL) supports diagnosis
• CXR: usually normal; obtain to rule out alternative diagnoses

Confirmatory testing#

Bronchial challenge testing (if spirometry normal but asthma suspected):

• Methacholine challenge: PC20 <4 mg/mL = positive
• Requires pulmonology referral in most settings
• Withhold bronchodilators before testing

Fractional exhaled nitric oxide (FeNO):

• FeNO >50 ppb strongly suggests eosinophilic airway inflammation
• Useful for predicting ICS response and monitoring adherence

Trial of therapy:

• If high clinical suspicion but testing inconclusive
• Start low-dose ICS for 6-8 weeks; significant improvement supports diagnosis

When to refer for specialist workup#

Pulmonology referral for:

• Diagnostic uncertainty (normal spirometry, atypical features)
• Need for bronchial challenge testing
• Severe or difficult-to-control asthma despite Step 4 therapy
• Consideration for biologics
• Frequent exacerbations (≥2/year) despite adherent therapy

What NOT to order#

• CT chest routinely (CXR sufficient)
• Bronchoscopy (not indicated for typical asthma)
• Serial spirometry more than annually in stable patients
• Total IgE for diagnosis (not specific)

Treatment#

Goals of therapy#

GINA treatment goals:

1. Achieve good symptom control (minimize day and night symptoms)
2. Minimize future risk of exacerbations, fixed airflow limitation, and side effects
3. Maintain normal activity levels including exercise

Specific targets:

• Daytime symptoms ≤2 days/week
• No nighttime awakenings due to asthma
• Reliever use ≤2 days/week
• No activity limitation
• FEV1 >80% predicted
• ≤1 exacerbation requiring oral steroids per year

Non-pharmacologic management#

Trigger avoidance:

• Dust mites: encasements for mattress/pillows, wash bedding weekly in hot water
• Pet dander: keep pets out of bedroom, use HEPA filter
• Tobacco smoke: smoking cessation essential; avoid secondhand smoke
• Exercise: pre-treat with SABA 15 minutes before if exercise-induced symptoms

Vaccinations:

• Influenza: annually (viral infections are major exacerbation trigger)
• Pneumococcal and COVID-19: per CDC guidelines

Asthma action plan (every patient should have one):

• Green zone: doing well—continue maintenance medications
• Yellow zone: getting worse—increase controller, add reliever, when to call
• Red zone: medical alert—seek immediate care
• Include specific peak flow or symptom triggers for each zone

GINA 2024 Step Therapy Overview:

• Step 1-2: PRN low-dose ICS-formoterol (preferred) OR low-dose ICS + PRN SABA
• Step 3: Low-dose ICS-formoterol maintenance + PRN (same inhaler)
• Step 4: Medium-dose ICS-formoterol maintenance + PRN
• Step 5: High-dose ICS-LABA + add-on (LAMA, biologic)

Key principle: ICS-containing reliever is now preferred over SABA-only at ALL steps.

Pharmacologic management#

ICS-LABA Combinations (Step 3-5):

Short-Acting Beta-Agonists (SABA) - Reliever:

SABA overuse warning: Using SABA >2 days/week indicates poor control. Using ≥3 canisters/year associated with increased exacerbation risk.

Long-Acting Muscarinic Antagonists (LAMA) - Add-on at Step 4-5:

Leukotriene Receptor Antagonists (LTRA):

FDA Boxed Warning for Montelukast: Risk of neuropsychiatric events including suicidal thoughts, agitation, depression. ICS is preferred controller.

Oral Corticosteroids (for exacerbations):

Patient counseling points#

For controller inhalers:

• “This is your most important medicine. Use it every day, even when you feel well.”
• “It takes 1-2 weeks to start working fully. Don’t stop because you feel better.”
• “Rinse your mouth and spit after using to prevent thrush.”

For reliever inhalers:

• “Use this when you have symptoms—wheezing, coughing, chest tightness.”
• “If you’re using this more than twice a week, your asthma isn’t well-controlled.”

For inhaler technique:

• Demonstrate proper technique at every visit
• MDI with spacer: shake, exhale, seal lips, press and inhale slowly, hold 10 seconds
• DPI: exhale away from device, inhale quickly and deeply, hold 10 seconds

Monitoring and follow-up#

Initial follow-up: 2-4 weeks after starting/changing therapy

Stable asthma: Every 3-6 months

Asthma Control Test (ACT): 5-question tool (score 5-25); ≥20 = well-controlled

Step-up and step-down:

• Step up if not well-controlled after 2-3 months of adherent therapy
• Consider step-down after 3 months of good control
• Never stop ICS completely in persistent asthma

Patient education#

What is this condition?#

Asthma is a lung condition that makes it hard to breathe. The airways in your lungs are swollen and sensitive. When something bothers them, they get more swollen and the muscles around them tighten up. This makes the airways narrow, so less air can get through.

Asthma is a long-term condition, but it can be controlled. Most people with asthma can live normal, active lives. The key is taking your medicines as prescribed and avoiding things that trigger your symptoms.

What you can do#

Take your controller medicine every day, even when you feel fine. This medicine keeps the swelling down in your airways.

Know your triggers and avoid them when you can. Common triggers include dust, pet dander, mold, pollen, smoke, strong smells, and cold air.

Keep your rescue inhaler with you at all times. Use it when you have symptoms like wheezing, coughing, or trouble breathing.

Follow your asthma action plan. This tells you what to do when your asthma gets worse.

Get a flu shot every year. Colds and flu can make asthma much worse.

When to seek care#

Call your doctor if you are using your rescue inhaler more than twice a week. Call if your symptoms are waking you up at night. Call if your asthma is getting in the way of your normal activities.

Go to the emergency room if you are having severe trouble breathing. Go if your rescue inhaler is not helping. Go if you cannot speak in full sentences because you are too short of breath. Go if your lips or fingernails are turning blue.

Questions to ask your doctor#

What triggers my asthma? Am I using my inhaler correctly? What should I do if my asthma gets worse? Do I need allergy testing? Is my asthma well-controlled?

Prognosis and monitoring#

Expected course#

With optimal treatment:

• Most patients achieve good symptom control
• Normal or near-normal lung function maintained
• Exacerbations are infrequent (≤1/year)

Without treatment:

• Progressive symptoms and activity limitation
• Frequent exacerbations
• Airway remodeling leading to fixed airflow obstruction

Prognostic factors for poor outcomes:

• History of near-fatal asthma
• Hospitalization or ED visit in past year
• Not currently using ICS
• Overuse of SABA (≥1 canister/month)
• Poor adherence

Monitoring parameters#

Complications to watch for#

Acute exacerbations: Most common complication; can be life-threatening. Prevention: adherent ICS use, action plan, trigger avoidance, vaccinations.

Fixed airflow obstruction: Chronic inflammation leads to airway remodeling. Prevention: early and consistent ICS use.

Medication side effects: ICS can cause oral thrush (5-10%) and dysphonia—rinse mouth after use.

Special populations#

Elderly/geriatric#

Diagnostic challenges:

• Symptoms may be attributed to aging, deconditioning, or heart disease
• COPD overlap common (asthma-COPD overlap syndrome)
• Consider empiric trial of ICS if high clinical suspicion

Treatment considerations:

• ICS remains first-line; no age-based dose adjustments for inhaled medications
• Assess ability to use each device; consider nebulizer if unable to use inhalers
• Spacer essential for MDI use in older adults

Beers criteria considerations:

• Avoid theophylline (narrow therapeutic index, toxicity)
• Use systemic corticosteroids cautiously (delirium, hyperglycemia, osteoporosis risk)
• SABA can cause tachycardia; use cautiously with cardiac disease

Chronic kidney disease#

Medication adjustments:

Special considerations: Inhaled medications minimally absorbed; no renal dose adjustments needed.

Other populations#

Pregnancy:

• Uncontrolled asthma poses greater risk to fetus than asthma medications
• Continue ICS (budesonide has most safety data)
• Continue LABA if needed for control
• SABA safe for rescue

Obesity:

• Obesity worsens asthma control and reduces ICS response
• Weight loss improves symptoms and lung function
• Higher ICS doses may be needed

Polypharmacy:

• Beta-blockers: cardioselective (bisoprolol, metoprolol) generally safe; avoid non-selective
• NSAIDs: can trigger bronchospasm in aspirin-exacerbated respiratory disease
• ACE inhibitors: cough side effect may confuse asthma assessment

When to refer#

Specialist referral criteria#

Pulmonology referral (routine):

• Diagnostic uncertainty
• Moderate-severe asthma not controlled on Step 3-4 therapy
• Frequent exacerbations (≥2/year) despite adherent therapy
• Consideration for biologics

Pulmonology referral (urgent):

• Life-threatening exacerbation (ICU admission, intubation)
• Severe asthma requiring frequent oral steroids

Allergy/immunology referral:

• Consideration for allergen immunotherapy
• Severe allergic asthma for biologic consideration

Urgency levels#

Smartphrase snippets#

Asthma, well-controlled: Asthma well-controlled on [ICS-LABA], ACT [X/25]. No exacerbations past year. Inhaler technique reviewed; continue current regimen.

Asthma, not well-controlled: Asthma not well-controlled with ACT [X/25], rescue inhaler use [X] times/week. Stepping up to [new regimen]. Action plan reviewed.

Asthma exacerbation: Asthma exacerbation with increased dyspnea and wheeze, SpO2 [X]%. Started prednisone 40mg x 5 days. Return precautions reviewed.

Related pages#

• Wheeze (complaint) — wheezing differential including asthma vs COPD
• Cough (Chronic) (complaint) — chronic cough differential including cough-variant asthma
• Dyspnea (Chronic) (complaint) — chronic dyspnea evaluation including asthma
• Dyspnea (Acute) (complaint) — acute dyspnea including asthma exacerbation
• Cough (Acute) (complaint) — acute cough including asthma exacerbation
• COPD (problem) — differentiate from asthma; asthma-COPD overlap
• Obstructive Sleep Apnea (problem) — OSA worsens asthma control; treat both conditions