What is a small inflamed elevation of skin that contains pus called?

The term used to describe a small inflamed elevation of the skin that contains pus is "pustule." Pustules are typically round and filled with a yellowish or whitish fluid, making them easily identifiable. They often appear in conditions such as acne, folliculitis, or infections, and their formation is generally due to an accumulation of pus, which consists of bacteria, dead white blood cells, and tissue debris arising from the body's immune response to infection or irritation.

In contrast, other terms you might encounter describe different skin lesions. For instance, a papule is a small, raised bump on the skin, but it does not contain pus; it can be firm or inflamed and is often less than 1 centimeter in diameter. A vesicle is a small fluid-filled sac that usually contains clear fluid rather than pus, often seen in conditions like chickenpox or herpes. An ulcer, on the other hand, refers to a deeper loss of skin, usually involving the epidermis and part of the dermis, and does not fit the description of a small, pus-filled elevation. This contextual understanding highlights why "pustule" is the correct answer in this scenario.