A 52-year-old man with chronic obstructive pulmonary disease (COPD) has been prescribed inhaled beclomethasone dipropionate 200 µg twice daily for 8 months. His serum cortisol level is normal, but he reports easy bruising and skin fragility. What is the most common systemic adverse effect of inhaled corticosteroids in long-term use that could explain these findings?

Explanation

## Most Common Systemic Adverse Effect of ICS Explaining Easy Bruising and Skin Fragility **Key Point:** Easy bruising and skin fragility in a patient on long-term inhaled corticosteroids (ICS) are classic manifestations of **skin atrophy and impaired wound healing** — a well-recognized systemic adverse effect of corticosteroid-induced collagen suppression. ### Why Skin Atrophy Is the Correct Answer Here The stem explicitly asks which systemic adverse effect **explains these findings** (easy bruising, skin fragility). These are textbook features of corticosteroid-induced skin atrophy: 1. **Mechanism:** - Corticosteroids suppress fibroblast proliferation and collagen synthesis in dermal connective tissue - Reduced dermal collagen → thinning of skin → fragility and easy bruising - Impaired wound healing due to reduced fibroblast activity and angiogenesis 2. **Systemic absorption of ICS:** Even at moderate doses (beclomethasone 400 µg/day), sufficient systemic absorption occurs to produce cutaneous effects, even when HPA axis suppression is absent 3. **Normal serum cortisol:** Rules out clinically significant HPA axis suppression (Option A), confirming that Cushing syndrome is not the explanation ### Why Other Options Are Less Correct | Option | Why Incorrect in This Context | |---|---| | A) HPA axis suppression / Cushing syndrome | Explicitly excluded by normal serum cortisol | | B) Osteoporosis | Most common *overall* systemic ICS effect, but does NOT directly cause easy bruising or skin fragility | | D) Immunosuppression / recurrent infections | Not consistent with the described skin findings | ### Incidence of Systemic Adverse Effects of ICS | Systemic Effect | Incidence | Explains Skin Findings? | |---|---|---| | Osteoporosis | 20–40% (long-term) | No | | Skin atrophy / bruising | 10–25% | **Yes** | | HPA axis suppression | 5–10% (high dose) | Partially (Cushing features) | | Immunosuppression | 2–3% | No | **High-Yield:** Skin atrophy, easy bruising, and impaired wound healing are among the most recognizable cutaneous systemic effects of ICS, occurring even at doses that do not suppress the HPA axis. This is because dermal fibroblasts are exquisitely sensitive to corticosteroid-mediated collagen suppression. **Clinical Pearl:** The combination of **normal serum cortisol + easy bruising + skin fragility** in a patient on long-term ICS is the classic presentation of ICS-induced skin atrophy — not Cushing syndrome and not osteoporosis. Osteoporosis is the most common systemic effect overall, but it does not produce these specific skin findings. [cite: KD Tripathi 8e Ch 20 (Corticosteroids); Harrison 21e Ch 396 (Cutaneous drug reactions); GINA/GOLD Guidelines on ICS adverse effects]