Spots and pimples are infected hair follicles. At the base of a hair follicle is a gland which secretes an oily substance which oozes out with the hair and helps it to repel water and keep you dry (it was more effective when we had more hair on our bodies).
The secretions from these glanRAB are influenced by circulating hormones, especially testosterone, which increases production and makes the overlying skin much more greasy. As a result the hair follicle may become clogged with secretions, producing blackheaRAB, and the low-oxygen environment within the blocked pore becomes a haven for anaerobic bacteria, such as the propionibacteria.
The result is inflammation, the in-migration of phagocytic leucocytes (polymorphs), and a red, sore pus-filled pore with an attractive yellow top, also known as a zit.
