Comedonal acne is one of the non-inflamed acne forms. Depending of the nature of comedones manifestations, comedonal acne can be mild, moderate or severe. The form is determined with the help of visual inspection including the number and structure of acne elements evaluation, sebum secretion, keratinization and keratosis processes level evaluation. In most cases, the appearance of comedonal acne does not involve the inflammatory process or pathogenic microflora development.
The main morphological elements are single comedones. Comedones can be open and closed depending on their formation. Open comedones appear in the case when sebum, dead skin cells and dirt accumulate in the pore at skin surface. As a result of sebum oxidization these clogs become darker and form a blackhead. Closed comedones are the small light-yellow nodules slightly protruding above the skin surface.
Closed comedo (or whitehead) forms due to the sebum and keratosis products accumulation deep into the hair follicle. As a result, sebum oxidization becomes impossible but favorable conditions for anaerobic pathogenic bacteria growth appear. This causes the development of inflammation and suppuration processes. As a rule, comedonal acne appears in people suffering seborrhea and various acne forms. Comedonal acne can also occur as a result of sun exposure and other physical factors.
As atrophy of sebaceous glands takes place, comedones transform into dense blackheads and cysts, resulting in hair follicles expansion. The skin thickens and becomes rough due to the elastic fibers amount decrease. A correct diagnosis is very important to determine an adequate treatment. Therapeutic methods used for papules, pustular and nodular-cystic formations are inappropriate for comedonal acne treatment.
Open and closed comedones
Micro-comedones are primary microscopic clusters of sebaceous glands secretion formed due to the hair follicle partial blockage. The blockage is caused by corneocytes (surface skin cells that constantly shed). Micro comedones are hardly visible on the surface of the skin.
Closed comedones (whiteheads) form due to the further sebum accumulation and its pressure on the clogged follicle. The main feature of closed comedo formation is nodules formation beneath the skin surface. Inflammatory processes are not very active, however favorable for anaerobic propionibacterium conditions cause superficial skin layers inflammations. Therefore, closed comedones are often called “time bomb”.
Open comedones (blackheads) form due to the continuous accumulation of sebum and corneocytes in the sebaceous gland leading to the hair follicle atrophy. The sebum becomes thick and over-saturated by korneocytes and can not be moved to the skin surface forming a dark plug. This plug is made of densely packed corneocytes (dead ckin cells), sebum (skin oil), propionic bacteria and staphylococcus.
Comedonal acne treatment
In the case of comedonal acne dermatologist usually recommend to remove cosmetics properly, stop using comedogenic skin care products and use comedolytic treatments like retinoids or Alpha and Beta Hydroxy Acids. The recommendations and algorithm of various acne forms treatment commonly include following medications: in the case of mild acne – topical retinoids, topical antibiotics, in case of moderate acne – topical retinoids and/or benzoyl peroxide. As an alternative means different products containing azelaic acid, AHAs and BHAs, benzoyl peroxide and hormonal therapy can be used.