A macule is a small, flat discolored area on the skin, specifically defined by its size. According to our reference, a macule is a circumscribed, flat area of discoloration that is less than 10 mm in diameter.
Understanding Macules
Let's explore what this means in more detail:
- Circumscribed: This means the discolored area has a defined border. It is not a blurry or faded discoloration.
- Flat: A macule is not raised or depressed. It's flush with the surrounding skin.
- Discoloration: The color of a macule is different from the normal skin tone. It can be lighter (hypopigmented), darker (hyperpigmented), red, or another color.
- Size: The key feature defining a macule is its size: less than 10 mm in diameter. This is roughly the size of a pencil eraser or smaller.
Macule vs. Patch
It's essential to understand how macules are distinguished from patches:
| Feature | Macule | Patch |
|---|---|---|
| Size | Less than 10 mm in diameter | Greater than 10 mm in diameter |
| Discoloration | Flat area of discoloration | Flat area of discoloration |
As shown in the table, the primary difference is the size. If a flat, discolored area exceeds 10 mm, it is classified as a patch rather than a macule.
Examples of Macules
Here are some examples of medical conditions that present with macules:
- Freckles: Small, tan or light brown spots caused by sun exposure.
- Some types of birthmarks: Certain birthmarks may present as flat, discolored macules.
- Early stages of certain rashes: Macules can appear as an early sign of various skin conditions.
In summary, a macule is a small, flat, discolored spot on the skin that measures less than 10 mm in diameter.
