What is a small pimple that does not contain fluid but can develop pus called?

A small pimple that does not contain fluid but can develop pus is called a papule. Papules are raised, solid lesions that are often a result of inflammation or infection. They typically present as small, red bumps on the skin and can be associated with various skin conditions, including acne.

When a papule becomes inflamed or infected, it can accumulate pus, which can give it a more pronounced appearance. This classification as a solid, non-fluid filled pimple differentiates it from other skin lesions.

In terms of the other options, verruca refers to warts caused by viral infection, comedones are clogged hair follicles that can be open (blackheads) or closed (whiteheads), and steatoma, often known as a sebaceous cyst, is a fluid-filled sac under the skin. None of these fits the description of a pimple that is solid and can develop pus, reinforcing that papule is indeed the correct term for this type of lesion.