What is the primary characteristic of a macule?

A macule is defined as a flat, discolored area of the skin that is typically less than one centimeter in diameter. The primary characteristic is that it represents a change in skin color without any elevation above the surrounding skin. This can occur due to various factors, such as increased pigmentation, loss of pigmentation, or vascular changes.

Understanding this characteristic is crucial in dermatology, as it helps diagnose conditions like freckles, flat moles, and certain types of rashes. When analyzing the other potential characteristics, a raised bump refers to a papule, a fluid-filled sac describes a vesicle or bulla, and a thickened area relates to a plaque or keratosis. Each of these terms describes distinct skin lesions, highlighting the importance of recognizing the specific nature of a macule in assessing skin disorders accurately.