Final answer:
A plaque is a flat, discolored area of skin, distinct from raised bumps, cyst-like lesions, or pus-filled sacs. It can become pus-producing when infected. Skin lesions like moles or potential skin cancers have specific features identified using the ABCD mnemonic.
Step-by-step explanation:
A plaque is a flat, discolored area of skin, often characterized by smooth spots of discoloration. Plaques are different from small raised bumps or lesions that resemble cysts with less defined boundaries. When a plaque becomes pus-producing, it is referred to as suppurative, indicative of an infection of the skin. An example of this would be acne, where inflamed hair follicles on the skin, or folliculitis, can become purulent, leading to the formation of lesions like a furuncle or abscess. In contrast, fluid- or pus-filled bumps are often characterized as encapsulated sacs which may be referred to as cysts. Certain skin lesions, such as moles or potential skin cancers, have distinguishing features which can be identified through the ABCDs: asymmetry, irregular borders, dark coloration, and diameter.