Our skin, the body’s largest organ, can develop various marks and spots. These changes are a normal part of skin health, ranging from temporary discolorations to more persistent features. One common type of skin lesion is a macule. Understanding these marks helps in monitoring skin health and recognizing when medical advice might be beneficial.
What Defines a Macule
A macule is a flat, discolored area on the skin that differs in color from the surrounding skin. It does not involve any change in texture, meaning it is neither raised nor depressed and feels smooth to the touch. You would not be able to feel a macule if you ran your finger over it.
These lesions generally measure less than 1 centimeter (about 0.4 inches) in diameter. Their color can vary widely, appearing lighter (hypopigmented), darker (hyperpigmented), or shades of red, pink, or blue. Macules can occur anywhere on the body and may appear as a single spot or as part of a larger rash.
Common Macule Types and Their Origins
Many common skin marks are macules. Freckles, for instance, are macules that often develop due to sun exposure and genetic predisposition. Flat moles, also known as nevi, are macules that differ from raised moles by their smooth, untextured surface. Some birthmarks, such as café-au-lait spots, are also macules, characterized by their flat, light brown appearance.
Macules can also arise from various causes, including inflammatory processes. Post-inflammatory hyperpigmentation, for example, can occur after skin injuries like acne lesions or insect bites heal. Certain infections, such as measles or rubella, can also appear as flat, discolored spots on the skin. Additionally, conditions like vitiligo, where the skin loses pigment cells, result in lighter macules.
When to Consult a Doctor
While many macules are harmless, seek medical advice if you notice any changes in an existing macule or if a new one appears. Consult a healthcare professional if a macule changes in size, shape, or color. Any development of new texture, such as a raised area, bleeding, or crusting, warrants attention.
Symptoms like itching, pain, or tenderness associated with a macule are also reasons for evaluation. When assessing flat moles or other suspicious macules, dermatologists often use the “ABCDE” rule to identify potential signs of melanoma, a type of skin cancer. This rule considers:
- Asymmetry (one half does not match the other)
- Irregular Border
- Varied Color (uneven shades)
- Diameter (especially if larger than 6 millimeters)
- Evolution (any change over time)