What is the characteristic of a plaque?

A plaque is characterized as a raised lesion that has a diameter greater than 1 cm and does not contain fluid. This definition aligns with the dermatological understanding of plaques, which typically present as elevated areas on the skin and may have a well-defined edge. They are often found in conditions such as psoriasis or eczema, where they can vary in color and texture but maintain the characteristic of being solid and raised.

In contrast, smaller raised lesions typically fall into categories such as papules, while flat lesions (which can also be of varying sizes) are considered macules or patches, depending on their dimensions. Fluid-filled lesions, such as blisters or vesicles, are entirely different from plaques, as they indicate a collection of fluid rather than a solid elevation of skin.