A macule on the skin is a flat, colored spot that's less than a centimeter wide and doesn't change the skin's texture or thickness. Think of it as a change in skin color only, without any raised bumps or depressions.
Understanding Macules
Macules are one type of primary skin lesion. This means they're the initial, unaltered changes seen on the skin's surface. They differ from other lesions because they are entirely flat and involve only color variation. The change in color may be:
- Hyperpigmented: Darker than the surrounding skin. This can be due to increased melanin production (e.g., sunspots, freckles).
- Hypopigmented: Lighter than the surrounding skin. This can be due to a decrease in melanin production (e.g., vitiligo).
The color change can be various shades of red, brown, black, or white. The size is key; if the lesion is larger than 1 centimeter, it's no longer classified as a macule.
Examples of Macules:
- Freckles: Small, flat, brown spots caused by sun exposure.
- Flat moles (nevi): Usually brown or black, can vary in size but are considered macules if under 1cm.
- Some birthmarks: Certain birthmarks appear as flat discoloration.
- Flat lentigines: Age spots or sun spots.
Differentiating Macules from Other Lesions:
It's important to distinguish macules from other skin lesions. A papule, for example, is raised above the skin's surface. A plaque is a larger, flat-topped raised area. Understanding the differences helps in proper diagnosis.
Definition: A flat, distinct, discolored area of skin less than 1 cm wide that does not involve any change in the thickness or texture of the skin.
