Acne begins in adolescence and resolves on average in the 2nd decade of life, however, some patients still have symptoms after the age of 35 years or more (about 1% of men and 5% of women).
There is a genetic influence on the evolution of acne, which can be enlarged or diminished by racial and environmental factors.
Phototherapy is a treatment modality used for acne light treatment of various dermatoses, produces very good results.
Their classification is made according to the type of radiation used (UVA or UVB), which varies according to the wavelengths.
History of the evolution of acne
Acne lesions are caused by the obstruction of the pilosebaceous follicles, due to:
increased sebum production and secretion; hyperkeratinization with obstruction of the pilosebaceous follicle, proliferation and action of bacteria; local inflammatory reaction.
The increase in stratum corneum of the skin (the most superficial and flat) composed of keratinocytes can be stimulated by male hormones (androgens) and the effect of irritation caused by lipids (“fat”).
The irritating effect of lipids occurs when they move through the duct, and the accumulation of lipids leads to formation of open comedones (blackheads) or closed (white carnation).
It is assumed that the sebaceous glands of individuals with acne have higher secretion levels than the noncarriers.
Acneic areas, the sebaceous glands of the pilosebaceous follicles are characterized by hypertrophied and atrophied hair. So, the sebum is eliminated, distributed uniformly in a thin layer on the skin, giving a shiny appearance.
The sebum depends on the action of androgenic hormones, which regulate the production of sebum. It is for this reason that in puberty period in which these hormones surge, we observed hypertrophy of the gland and increased secretion.
Due to a genetic predisposition, there is a thickening (hyperkeratinization) in the pilosebaceous follicle, which combined with fat, so a mass inside the channel. This generates the comedo (blackhead) that can be open (blackheads) or closed (white carnation).
The bacteria act on the accumulated sebum and promote inflammation of the skin, forming lesions that are red, painful and pus. The main bacteria involved is called Propionibacterium acnes (P. acnes) that is normally present in the skin of all people, but in greater quantities in those with acne.