An inflamed pimple containing pus is a:

A pimple that is inflamed and contains pus is classified as a pustule. Pustules are typically seen in conditions such as acne and are characterized by a raised, inflamed area filled with pus, indicating the presence of infection or inflammation. The presence of pus is a key feature that distinguishes pustules from other skin lesions.

In contrast, a comedo refers to a clogged hair follicle, which can either be open (blackhead) or closed (whitehead), but it does not have pus. A crust is a dry, rough mass that forms over a healing sore or injury, often made up of dried blood, serum, or pus, but it is not itself an inflamed lesion. A cyst is a closed sac filled with fluid or semisolid material, which can be deeper within the skin, but it doesn't typically indicate active inflammation in the same way that a pustule does. Understanding these distinctions is crucial in identifying various skin conditions accurately.