What condition describes a significant infection of a hair follicle?

The condition that describes a significant infection of a hair follicle is known as a furuncle. A furuncle, commonly referred to as a boil, occurs when a hair follicle becomes infected, leading to the accumulation of pus and sometimes painful swelling. This infection often arises from bacteria, particularly Staphylococcus aureus, and can result in the formation of a firm, painful lump filled with pus.

In contrast, folliculitis refers to the inflammation of hair follicles, which may not always be due to a significant infection and often presents as small, red bumps. Tinea capitis is a fungal infection of the scalp and is unrelated to bacterial infections of hair follicles. Psoriasis is a chronic skin condition characterized by red, scaly patches and does not stem from infections of hair follicles. Understanding these distinctions helps clarify why furuncle is the correct condition among the options listed, as it specifically denotes a more considerable infective process involving hair follicles.