Folliculitis is caused by a bacterial infection of the hair follicles. If the folliculitis is severe and there is obvious surrounding swelling, it is known as a furuncle or boil. When multiple furuncles involve several hair follicles, it forms a carbuncle. Thus, the infection severity differs between folliculitis, furuncles, and carbuncles. How is folliculitis treated? First, it is important to maintain clean and hygienic skin and to enhance the body's immune system. Treatment primarily involves topical medications. In the early stages before abscess formation, mupirocin ointment can be used. If there is significant surrounding swelling, ichthammol ointment or topical iodine complex can be used. For more severe cases of folliculitis, oral antibiotics may be selected based on the condition, including penicillins such as cephalosporins, or erythromycin and other macrolide antibiotics, but it is important to ensure there is no allergy to these antibiotics before use.