Final answer:
Secondary lesions are changes that occur in the skin due to secondary factors like infection, injury, or the healing process, which alter the appearance of primary skin lesions.
Step-by-step explanation:
Secondary lesions are changes to the skin that evolve from primary lesions or develop as a consequence of the patient’s activities such as scratching, infection, or the healing process. Unlike initial skin changes that occur as a direct result of a disease process (primary lesions), secondary lesions can be attributed to factors such as changes caused by scratching, the presence of a secondary infection, or the healing and progression of an initial lesion. Examples of secondary lesions include crusting of a vesicle or an ulcer which can result from a primary lesion becoming infected, inflamed, or otherwise altered.
In the context of various infections, secondary lesions can manifest due to a range of causes including physical damage to the skin such as sunburn or an existing condition exacerbated by factors such as poor hygiene or limited exposure to the sun. For example, a primary lesion caused by a systemic infection like varicella-zoster virus can lead to secondary bacterial infections when the body's immune defenses are weakened or damaged.