Which of the following lesions is a large vesicle that is filled with fluid?

A large vesicle filled with fluid is referred to as a bulla. A bulla is typically greater than 1 centimeter in diameter and can occur in various skin conditions, often as a result of blisters, burns, or other inflammatory processes. The distinguishing characteristic of a bulla is its size and the presence of a clear fluid within, setting it apart from smaller lesions such as vesicles, which are less than 1 centimeter.

The other types of lesions have different definitions and characteristics: a papule is a small, raised lesion that is typically less than 1 centimeter in diameter, often solid and can be caused by conditions such as acne or hives; a nodule is larger than a papule and extends deeper into the skin, usually solid and firmer; and a scale refers to flakes or plates that form on the skin surface, resulting from the shedding of dead skin cells and is not a fluid-filled vesicle. Understanding these distinctions is essential in medical coding and diagnosing various dermatological conditions.