A 28-year-old woman with moderate persistent asthma is started on inhaled corticosteroids (ICS). Her colleague, a 32-year-old man with mild intermittent asthma, uses a short-acting beta-2 agonist (SABA) only as needed. Which feature best distinguishes the management approach between moderate persistent and mild intermittent asthma?

Explanation

## Distinguishing Feature: Controller vs Reliever Therapy **Key Point:** The fundamental difference between mild intermittent and moderate persistent asthma is the need for daily controller medication. ### Classification & Treatment Hierarchy | Asthma Severity | Daytime Symptoms | Nighttime Symptoms | FEV₁ | Controller Therapy | |---|---|---|---|---| | **Mild Intermittent** | ≤2 days/week | ≤2 nights/month | ≥80% predicted | None (SABA PRN only) | | **Mild Persistent** | >2 days/week but not daily | 3–4 nights/month | ≥80% predicted | Low-dose ICS | | **Moderate Persistent** | Daily symptoms | >1 night/week | 60–80% predicted | Medium-dose ICS ± LABA | | **Severe Persistent** | Throughout the day | ≥4 nights/week | <60% predicted | High-dose ICS + LABA ± oral corticosteroid | **High-Yield:** The step-wise approach mandates: - **Mild intermittent:** SABA as needed (no daily therapy) - **Mild persistent and above:** Daily ICS-based controller therapy ### Clinical Pearl **Clinical Pearl:** The transition from mild intermittent to mild persistent asthma (even one extra symptom day per week or one extra nighttime awakening per month) triggers the need for daily controller medication. This is the critical threshold in asthma management. ### Why Daily Controller Matters 1. **Inflammation control:** Daily ICS suppresses airway inflammation, reducing exacerbation risk and improving lung function trajectory 2. **Symptom prevention:** Controllers prevent symptoms; SABAs only relieve acute symptoms 3. **Mortality & morbidity:** Inadequate controller therapy in persistent asthma increases risk of severe exacerbations and death **Mnemonic:** **STEP-UP** = Symptom frequency determines therapy: **S**evere/persistent → daily controller; **T**ransient/intermittent → PRN reliever only.