Which of the following best defines a boil?

A boil is best defined as a localized infection that creates a lump filled with pus. This condition typically occurs when bacteria infects a hair follicle or oil gland, leading to inflammation and the accumulation of pus at the site. The body responds to the infection by sending white blood cells to fight the bacteria, which contributes to the formation of a painful, swollen lump. Understanding the nature of boils is crucial for estheticians as they must recognize such infections to avoid exacerbating the condition during skin treatments and advise clients appropriately.

The other choices describe different skin conditions. An allergic reaction involves the body’s immune response to certain products, which is not what a boil is. A chronic inflammatory skin condition refers to ongoing issues like eczema or psoriasis, while a benign skin tumor refers to non-cancerous growths on the skin, none of which encompass the characteristics of a boil.