Dear Dr. Roach: How do pimples form? Why do they itch? How can I remove them?
Answer: Acne is caused by plugged hair follicles, which are associated with sebaceous (oil-producing) glands. These are more likely to be plugged under control of androgenic hormones; with increased oil production; in the presence of the bacteria Cutibacterium acnes; and with inflammation. These are in turn affected by many factors, such as skin trauma, stress, amount of body fat and diet. Acne is very common in adolescents but can continue to be a problem in women and men in their 50s and older.