What does the term furuncle refer to?

The term furuncle specifically refers to a boil, which is a painful, swollen area on the skin that is typically filled with pus. It develops around a hair follicle and is caused by bacterial infection, often resulting from Staphylococcus aureus bacteria. This condition manifests when an infection affects both the hair follicle and the surrounding tissue, leading to inflammation and the formation of a rounded lump under the skin. Recognizing a furuncle is important in cosmetology, as it can impact treatments and the overall health of the skin.

The other options describe different skin conditions that do not fit the definition of a furuncle. A cyst formed in hair follicles is not necessarily infected or filled with pus as a furuncle is. Skin acne typically presents differently and does not involve the same formation as a boil. A skin rash can have various causes and does not involve the localized infection characteristic of a furuncle.