Certified Medical-Surgical Registered Nurse Practice Exam 2026 - Free Practice Questions and Study Guide

The correct answer highlights allergens and radiation as external factors that can damage the skin.

Allergens, such as certain chemicals, plants like poison ivy, or materials like nickel, can trigger allergic reactions, resulting in inflammation, rashes, or dermatitis, effectively harming the skin. Radiation, which includes ultraviolet rays from the sun or exposure to various forms of ionizing radiation, can lead to skin damage, sunburns, and even increase the risk of skin cancer over time.

These factors are distinctly external, impacting the skin from the outside. In contrast, emaciation relates more to nutritional deficiencies and is an internal factor that affects the body's overall health, while infections are typically caused by pathogens penetrating the skin, but they don’t strictly fit the category of external environmental factors.