Which of the following is a common symptom of sun damage?

Loss of elasticity is a well-documented symptom of sun damage. Over time, exposure to ultraviolet (UV) radiation leads to the breakdown of collagen and elastin fibers in the skin, which are critical for maintaining its structure and firmness. This degradation results in sagging and wrinkled skin, contributing to an overall loss of elasticity.

In contrast, increased moisture is not typically associated with sun damage; rather, prolonged sun exposure can actually dehydrate the skin, leading to a rougher texture. Skin thickening can occur as a defense mechanism to protect against UV radiation, but it is not the primary symptom people experience due to long-term damage. Finally, sun damage often leads to increased redness or discoloration due to inflammation and other reactions in the skin, contrary to a reduction in redness. Hence, loss of elasticity is indeed the hallmark symptom of sun damage in this context.