Acne, or pimples as they are popularly known is a common skin infection which mostly occurs in adolescence (during puberty) on the skin due to increase in the production of the hormone testosterone in both males and females. The most common areas of acne appearance are the face, near the chest and the back as they have more sebaceous follicles (which are responsible for secreting sebum, an oily liquid that keeps the skin from drying). When there is an excess secretion of sebum, it can result in the formation of acne or pimples. The dirt, oil and dead skin cells clog the skin pores which give rise to acne.
These slowly reduce in number and usually disappear by the age of mid-20s. Acne leaves a scar when there is an inflammation in the dermis (inner layer of the skin) and it tries to heal itself resulting in overproduction of collagen.
Keeping the skin clean and free of sweat and excess oil can reduce the formation of pimples. Apart from these reasons, acne can also be due to the wrong diet, hormonal changes, certain medications which contain corticosteroids, androgens or lithium, or can even be genetic.
One needs to visit a dermatologist in order to identify the root cause of the problem and the correct treatment. Popping those pimples or touching them constantly are not the right ways to get rid of them as this will leave a mark on that spot. Nowadays, there are many treatments like chemical peels, microdermabrasion, laser therapy, medicated creams and oral medications are available to treat acne and acne scars.