A macule is a spot of discoloration on the skin which is smaller than a third of an inch (one centimeter) across. Larger areas of discoloration are known as patches. Maculues can be caused by any number of things, and may be a cause for concern in some cases, or an utterly unremarkable finding in others. A dermatologist can provide more information about a specific macule, including access to diagnostic testing if there is a concern that the spot is a sign of an underlying medical issue.
Several features characterize a macule and differentiate it from other types of skin abnormalities. The small size of the spot is one distinguishing feature, and it can be any color, although the spots tend to manifest in shades of brown and whites. Macules are also flat, causing no change in the thickness or texture of the skin. When someone touches a macule, it should not feel any different from the surrounding skin.
Many people are born with macules caused by uneven distributions of pigment. These small marks are generally not a cause for concern. Likewise, macules can develop over time in response to sun exposure, injuries, and other factors, and the mark is not necessarily an indicator that someone is in medical danger. In other cases, a macule can be a sign of an underlying medical problem, ranging from a dermatological condition to organ failure.
If a spot appears suddenly, it can bear further watching. Changes in color, shape, and size are signs that an ongoing process is occurring and it may be a good idea to consult a dermatologist for advice. If a spot causes a change in skin texture, it is no longer a macule, and there is a chance that it may be a malignancy. People can often tell if a spot is a cause for concern based on their medical history; someone who always freckles in summer, for example, will probably not view the emergence of a macule as a cause for concern, while someone who normally has clear skin and wakes up with an array of white dots on the arms might be worried.
If a dermatologist has concerns about a macule, a request for a biopsy will usually be made. During the biopsy, part or all of the mark is removed for further study in a laboratory to check for signs of abnormalities. Sometimes the doctor will remove the whole mark in case it is malignant, to save the patient a second procedure to take it off. Macules can also be removed when they are known to be benign if a patient finds them aesthetically unpleasing.