Asthma

30-Second Snapshot

Control & Severity - Two Different Questions

Students mix these up constantly. Controlasks "how is the patient doing right now, on their current regimen?" Severityasks "how much treatment does it take to keep them there?" You can only answer severity retrospectively, after months of optimized therapy.

GINA symptom control (last 4 weeks)

Severity, defined the modern way

GINA deliberately moved away from grading severity by symptom frequency at diagnosis, because patients with "mild" symptoms can still have fatal attacks. Severity is now assessed afterthe patient has been on optimized treatment for a few months, based on the step of therapy required to achieve control.

Risk factors worth screening for at every visit

• SABA overuse:≥3 canisters (200 doses each) per year raises exacerbation risk; more than 1 canister per month raises mortalityrisk. This is one of the single best predictors of a bad outcome you have.
• Inadequate ICS:not prescribed, poor adherence, or wrong inhaler technique.
• Ongoing exposure to smoke, allergens, occupational irritants.
• FEV1 <60% predicted, elevated eosinophils, or any exacerbation in the past year.

Pathophysiology - Why Each Drug Class Exists

The airway smooth muscle narrows through three mechanisms working together: smooth muscle contraction(the fast, reversible part), remodeling(structural, slow, less reversible), and mucus pluggingfrom goblet cell hypersecretion. Map the inflammatory cascade to the drug list and the whole chapter stops being memorization.

The allergic cascade

In allergic asthma, inhaled allergen binds IgE sitting on mast cells and macrophages. Within minutes (the early-phase reaction), those cells degranulate and dump histamine, leukotrienes C4/D4/E4, prostaglandins, and platelet-activating factor. The result is smooth muscle contraction, mucus secretion, and vascular leakage that thickens and narrows the airway wall.

Six to nine hours later, a late-phase reactionrecruits eosinophils, T lymphocytes, basophils, neutrophils, and more macrophages. TH2 lymphocytes release IL-4, IL-5, and IL-13, the cytokines that drive allergic inflammation and that most of the newer biologics are named after. Eosinophils then release granule proteins and leukotrienes that injure the airway epithelium directly, which is what heightens hyperresponsiveness further.

Map the pathway to the pharmacy

Clinical Presentation

Chronic asthma

Episodic shortness of breath, chest tightness, cough (often worse at night or early morning), and wheeze, frequently triggered by exercise, cold air, allergens, or infection. On exam you may hear expiratory wheeze and a dry cough, but physical exam findings are frequently completely normal between attacks, this is one of the most tested facts in the chapter. Don't let a normal lung exam talk you out of the diagnosis.

Acute severe asthma

Uncontrolled inflammation, mucus, and bronchospasm progress to airway narrowing that stops responding well to bronchodilators. Patients are anxious, dyspneic, and may only manage a few words per breath. Look for tachypnea, tachycardia, pallor or cyanosis, and a hyperinflated chest using accessory and supraclavicular muscles. Wheeze can be both inspiratory and expiratory, and breath sounds may be diminished with severe obstruction.

Diagnosis

Diagnosis needs two things: a historyconsistent with asthma (recurrent wheeze, cough, chest tightness, dyspnea that vary in intensity, often with known triggers or a personal/family history of atopy) and objective confirmationof variable expiratory airflow limitation.

Confirming variable airflow limitation (need at least one)

• Positive bronchodilator reversibility:FEV1 (or FVC) increases ≥12% and ≥200 mLfrom baseline, 10–15 minutes after SABA. Hold albuterol ≥4 hours and long-acting bronchodilators 1–2 days before testing so you don't mask the response.
• Excessive PEF variability:more than 10% variability across twice-daily peak flow readings over 2 weeks.
• Improvement after 4 weeks of controller treatment:same ≥12%/200 mL FEV1 threshold, checked after a therapeutic trial instead of a single albuterol dose.
• Positive bronchial challenge:a fall in FEV1 after methacholine (or exercise/mannitol) provocation, used when baseline spirometry is normal but suspicion remains high.

Baseline obstruction looks like FEV1/FVC <80%(or below the lower limit of normal) with a positive bronchodilator response as above. If the workup is unclear after all of this, refer to a specialist rather than guessing.

Rule out the mimics

Chronic upper airway cough syndrome, GERD, heart failure or arrhythmia, COPD, obstructive sleep apnea, pulmonary embolism, bronchiectasis, cystic fibrosis, tuberculosis, and anxiety can all present with asthma-like symptoms. If the history, exam, and spirometry don't line up, work through this list before treating empirically.

Treatment - GINA Tracks and Stepwise Therapy

Goals:good symptom control with normal activity levels, and minimizing future risk, exacerbations, fixed airflow limitation, and treatment side effects. Every persistent asthma patient starts on ICS-containing therapy; there is no step that's ICS-free once symptoms are more than occasional.

Stepwise therapy, ages 12+ (Track 1, preferred column)

Assess control 2–6 weeks after any change. Step up if uncontrolled (after checking technique, adherence, and triggers first). Step down only after ≥3 consecutive months of good control, typically by reducing ICS dose 25–50% at a time. Consult an asthma specialist at Step 4 and above; consider it at Step 3.

MART dosing limits

Maximum formoterol exposure with budesonide (Symbicort) or beclomethasone (Dulera) MART is 12 inhalations in 24 hoursfor age 12+ (8 for ages 4–11). The reliever dose is always the low-doseICS-formoterol strength, even if the patient's maintenance inhaler is a higher-dose formulation, so double-check they have the correct strength device to make that math work.

Nonpharmacologic therapy

• Educationon adherence, self-management, and when to seek care is not optional, it's part of the prescription.
• Short-term (about 2 weeks) home PEF monitoring can assess response to a therapy change; longer-term PEF monitoring is mainly for patients with a history of sudden severe attacks, difficult-to-control severe asthma, or poor symptom perception.
• Avoid known triggers (animals, smoke, occupational irritants); push smoking cessation, including vaping, which is independently linked to worse symptoms.
• Every patient needs a written asthma action plancovering their usual meds, when/how to step up or start oral corticosteroids, and when to seek emergency care.

Dosing Reference

Relievers and maintenance inhalers

Comparative ICS daily dosing, ages 12+ (mcg/day)

Acute severe exacerbation drug doses (≥12 years old)

Class-by-Class Detail

Acute Severe Asthma - ED Management

Goal number one in an acute exacerbation is preventing death by recognizing deterioration early and treating fast. Give the first three bronchodilator treatments together and reassess at 1 hour.

Triage by clinical status

Any of drowsiness, confusion, or a silent chestmeans skip the algorithm: consult ICU, start SABA and oxygen, and prepare for possible intubation.

Reassess at 1 hour

• FEV1 or PEF 60–80% predicted/best and symptoms improved:consider for discharge planning.
• FEV1 or PEF <60% predicted/best, or no clinical response:continue treatment as above and reassess frequently; treat as severe and reassess for ICU if still deteriorating.

Obtain history and exam whiletreatment is already running, don't delay bronchodilators to finish the interview. Screen for anaphylaxis, complicating infection, and risk factors for asthma-related death in parallel. Arterial blood gases are reserved for patients doing poorly or deteriorating; get a CBC only if there are signs of infection (fever, purulent sputum).

Self-management for early worsening (before it becomes an ED visit)

On MART, the written action plan for early/mild worsening is to increase the reliever(ICS-formoterol as needed, up to a total formoterol dose of 72 mcg/day) and continue maintenance therapy. For late/severe worsening, at least double the maintenance ICS (consider escalating to high dose, max 2000 mcg/day BDP-equivalent), and add oral corticosteroids while contacting the prescriber. For Track 2 patients, the action plan instead centers on increasing SABA frequency and starting oral corticosteroids at the same trigger points.

Exercise-Induced Bronchospasm & Asthma-COPD Overlap

EIB

• SABA 5–20 minutes before exerciseknown to trigger symptoms; this pre-treatment dose does notcount toward the reliever-overuse tally used for control assessment.
• Low-dose ICS-formoterol works as pre-treatment too if the patient is already on a MART regimen.
• Montelukast 10 mg ≥2 hours before exercise (max 1 dose/24h) is an option, but shouldn't be used this way if the patient is already taking it for another indication.
• Warm up before exercise; this alone reduces EIB severity in many patients.

Asthma-COPD overlap

Persistent airflow limitation with features of both diseases. Diagnostic criteria are debated and these patients tend to be more symptomatic and are often excluded from major trials, so the evidence base is thin. Practically: still avoid LABA or LAMA monotherapy (the asthma rule), still be cautious with ICS/maintenance oral steroid dosing given pneumonia risk (the COPD rule), and still require FEV1/FVC <70% for diagnosis. Management generally follows the asthma pathway: start around Step 3–4 and keep the ICS dose low-to-moderate.

Monitoring

Patient Counseling

High-Yield Recall Sheet