Final answer:
Localized infections of hair follicles that are deep and often pus-filled are known as boils or folliculitis, which can become more severe and turn into furuncles commonly treated with antibiotics and sometimes drainage.
Step-by-step explanation:
Localized infections of hair follicles are called boils or folliculitis. Folliculitis generally presents as itchy, red bumps or pus-filled pimples. It can stem from factors such as sweat, ingrown hairs, irritations from shaving, and wearing tight clothing. Although folliculitis often resolves on its own, if symptoms persist, worsen, or recur frequently, medical intervention may be needed, which can include topical antibiotics.
On the other hand, when the infection of the hair follicle becomes more severe, it can develop into a furuncle, commonly known as a boil. Boils are deeper infections often caused by Staphylococcus bacteria and may require medical treatment, especially if they spread, increase in size, or are accompanied by systemic symptoms like fever. In such cases, draining the boil and using antibiotics might become necessary.