What is the word that refers to a skin lesion that has a wavy margin, such as ringworm?

The term that describes a skin lesion with a wavy margin, such as that seen in ringworm, is "serpiginous." This word is derived from the Latin word "serpens," meaning serpent, which aptly captures the undulating or wave-like appearance typical of certain dermatological conditions, particularly those with a peripheral spreading pattern like tinea corporis (ringworm).

In contrast, "vesicular" pertains to lesions that contain fluid-filled blisters and would not accurately describe the margin of a lesion. "Macular" refers to flat, discolored areas on the skin that do not have a raised or wavy margin. Lastly, "ulcerative" indicates lesions that involve the breakdown of the skin, often leading to open sores, which does not align with the characteristic wavy margins present in a serpiginous pattern. Thus, the choice of "serpiginous" is the most accurate in describing skin lesions with wavy margins.