How are secondary skin lesions characterized?

Secondary skin lesions are characterized by changes that occur after the initial stage of skin infirmity, reflecting alterations in the skin's texture and structure. They often arise from primary lesions or conditions and can present in various forms, such as abnormalities in the surface of the skin through either raised areas or depressions. This includes features like scales, crusts, ulcers, and scars, which can indicate a progression or evolution of skin disease.

The correct choice highlights the defining aspect of secondary lesions, which involves either piles of material on the skin's surface, such as crusts or scales, or depressions like ulcers or fissues. These characteristics demonstrate visible changes in the skin beyond the primary lesions.

The other options do not adequately encompass the transformation that defines secondary lesions. For instance, identifying lesions by color alone, or associating them exclusively with redness or pustules, overlooks the complexity and variety of presentations that secondary lesions can exhibit. This complexity is critical to understanding how these lesions relate to underlying skin conditions and their progression.