Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

What is a plaque?

1. Serous fluid trapped under skin less than 0.5cm in diameter

2. Generalized redness

3. Raised spot of color change greater than 0.5cm in diameter

4. Loss of superficial skin layer

The correct answer is: Raised spot of color change greater than 0.5cm in diameter

A plaque is defined as a raised area of skin that has a color change and measures greater than 0.5 cm in diameter. This characteristic allows it to be distinctly recognized among other types of skin lesions. Plaques often have a defined border and can result from various dermatologic conditions such as psoriasis, eczema, or other inflammatory processes, where the outer layer of the skin forms elevated patches due to factors like inflammation or the thickening of the skin. The other definitions focus on different types of skin changes or lesions. For instance, serous fluid trapped under the skin refers to a vesicle or bulla, which would be smaller than what is defined as a plaque. Generalized redness describes erythema, an increase in blood flow to the skin, without the raised characteristics that classify a plaque. The loss of the superficial skin layer pertains to erosion or ulceration rather than a raised lesion. Thus, the defining feature of a plaque as a raised color change larger than 0.5 cm makes it distinct and clearly identifiable among other skin conditions.