What type of lesion is a raised, often itchy bump?

A raised, often itchy bump is accurately described as a wheal. Wheals are characterized by their elevated, superficial nature and are typically a sign of an allergic reaction or other inflammatory response in the skin. They are often transient, meaning they can appear and disappear relatively quickly, and frequently are associated with itching due to the release of histamines in the skin.

Options like macules, vesicles, and nodules refer to different types of lesions. Macules are flat, discolored areas that are not raised, while vesicles are small fluid-filled sacs that can also be raised but are typically more specific in their presentation, often resulting from conditions like herpes or chickenpox. Nodules are larger, solid lesions that extend deeper into the skin and may not have the same transient characteristics or itchiness as wheals. This highlights why the correct identification of a wheal is crucial in understanding skin reactions and their underlying causes.