Which of the following is the most common local adverse effect of inhaled corticosteroids and can be minimized by rinsing the mouth with water immediately after inhalation?

Explanation

## Local Adverse Effects of Inhaled Corticosteroids **Key Point:** Oral candidiasis is the most frequent local side effect of ICS, occurring in 5–10% of patients, and is entirely preventable with proper inhaler technique and post-inhalation mouth rinsing. ### Pathophysiology of Oral Candidiasis 1. **Local immunosuppression** — ICS deposit directly in the oropharynx, suppressing local T-cell and neutrophil function 2. **Altered oral flora** — reduced local immunity favors overgrowth of *Candida albicans* 3. **Dose-dependent risk** — higher ICS doses and poor technique increase deposition in mouth 4. **Reversible condition** — responds well to topical antifungals (miconazole, nystatin) **Mnemonic: ORAL** — **O**pportunistic fungal infection, **R**educed local immunity, **A**lbicans overgrowth, **L**ocal deposition in mouth ### Prevention Strategy **High-Yield:** The single most effective prevention is **mouth rinsing with water immediately after inhalation** — this physically removes ICS particles from the oropharynx before they suppress local immunity. Additional preventive measures: - Use a spacer device (reduces oropharyngeal deposition by ~80%) - Rinse mouth with water (do NOT swallow) - Gargle if possible - Use proper inhaler technique to maximize lung deposition ### Why Other Options Are Incorrect | Adverse Effect | Frequency | Mechanism | Prevention | |---|---|---|---| | **Oral candidiasis** | 5–10% (most common) | Local immunosuppression | Mouth rinsing, spacer | | Laryngeal edema | Rare (<1%) | Hypersensitivity reaction | Avoid in patients with ICS allergy | | Bronchospasm | Rare (<1%) | Paradoxical airway reaction | Rare; use β₂-agonist before ICS if occurs | | Allergic rhinitis exacerbation | Not a known ICS effect | ICS actually *treat* allergic rhinitis | Not applicable | **Clinical Pearl:** Patients with oral candidiasis should be counseled to rinse their mouth and use a spacer; if candidiasis persists despite these measures, consider topical antifungal therapy (miconazole oral gel 5 mL four times daily) [cite:Harrison 21e Ch 297].