First, let's talk about how pimples form in the first place. Acne is a complex skin disease that has many factors, influences, and triggers. For example, genetics, diet, lifestyle, skin care products, makeup, and stress can all play a role in the development or worsening of acne. A basic explanation for why a Zit forms, however, is, "When cells in the oil glands stick together and clog the pores, oil forms, which leads to inflammation," says board-certified dermatologist Joshua Drawer, MD. From there it can build up into different types of acne, like blackheads, whiteheads, papules, pustules, and cysts.
Neck acne in particular can have several factors. First, it is similar to the face in that it has a higher concentration of pores. "Similar to the face, there is a risk of outbreaks in the neck due to the high concentration of oil glands," says Zeichenner. But the neck is also a sweet spot where many problems with pore clogging and skin irritation converge.
For example, people who wear makeup can apply it to their necks too, but may not be as diligent in removing it in the evening as it is on their face. People with long hair can see pimples on the back of their necks from neck care products and oil. Sweat can build up on the collars of exercise equipment and clothing and cause irritation in the area. Hair removal while shaving, etc. can cause breakouts, irritation and ingrowth. Or hormonal acne, which typically forms around the chin and jaw, can spread to the neck.
So rest assured, if you are dealing with acne here, you are definitely not alone and it is perfectly normal. It can only take a few changes to get under control.