Being a human is a pretty sweet deal on the whole. Then again, we do have our own unique problems to deal with: bills, existential crises, and acne. But why do humans have it so bad when it comes to acne, while most other animals appear to get off scot-free? Like many things, you can blame your evolutionary past.
Acne, scientifically known as Acne vulgaris, occurs when hair follicles become clogged up with skin oils and dead skin cells. Those characteristic red bumps emerge because the dermal layer of skin has become irritated and inflamed, often as a response to Propionibacterium acnes, a bacteria that usually live peacefully on our outer skin and deep in our pores.
Despite what many assume, cleanliness has relatively little to do with acne, but it can be affected by factors like diet and genetics. It’s also one of the most common diseases in the world, although some groups of people (such as the Kitavan Islanders of Papua New Guinea) don’t seem to get acne at all. It usually arises in early puberty, namely because hormone changes cause the sebaceous glands in the skin to kick out more of an oily secretion known as sebum. Most mammals produce sebum as a way of lubricating and waterproofing their skin by creating a waxy coating. It can also help to protect your body against illness by acting as a sealed barrier to germs that might penetrate the skin.