Copious research points unanimously to four factors as the causes of acne - namely, these are:
Accordingly, all of the above together contribute to the formation of acne. To highlight the mechanism even more thoroughly, it all starts with excessive sebum production, due to various reasons e.g. hormonal imbalance. Subsequently, skin cells keratinization is also stimulated which makes shedding of dead skin cells more difficult for the skin - they accumulate on the skin surface, creating a perfect environment for particular bacteria species. Going further, Propionibacterium acne strains multiply and secrete irritant free fatty acid to their surroundings which give rise to a strong inflammatory response - the whole circle closes here and the cycle propels itself.
Even though their causes are very much the same, miscellaneous forms of acne can look totally different from one another as well as vary in their intensity. Let’s take a closer look at and compare diverse acne lesions.
Whiteheads and blackheads have been put together in a paragraph since both of them directly result from accumulation of sebum, keratin and melanin in the pores. The only detail which makes them disparate is the fact that in blackheads, the mentioned substances are exposed to the air, while in whiteheads, they stay hidden. Oxygen from the air oxidizes the pore content which makes the lesion look black while whiteheads, unoxidized, are harder to spot with the naked eye hence most of the time they are only visible when stretching the skin with one’s fingers.
Papules often occur together with whiteheads and blackheads nonetheless, contrarily to them, they are an inflammatory type of lesion. The papule is a dermatological term for a firm, hard elevation of the skin of <0,5cm in diameter which can be both in the color of one’s skin or slightly reddened. When differing them from pustules, they contain no pus nor have no accentuated center.
Pustules are the typical, so - called “pimples”. They are what most often pops up in our minds when we think of acne - a bump with a center filled with pus on a reddened base, easily purulent when picked on. Needless to say, it is an inflammatory lesion since pus is an end product of a fight between the immune system and the bacteria.
Nodules and cysts are the most severe forms of acne. They are located in the deeper skin layers hence demand more attention when treating them. Dermatologically speaking, a nodule is of <1 cm diameter while a cyst has <2cm in diameter. Since, as mentioned earlier, they stem from the dermis, they will probably result in scar formation upon disappearance.