Introduction to Acne...
Acne is a general term used for acneiform eruptions. It is usually used as a synonym for acne vulgaris, but may also refer to:
Acne aestivalis, Acne conglobata, Acne cosmetica, Acne fulminans, Acne keloidalis nuchae, Acne mechanica, drug-induced acne, Acne miliaris necrotica, Acne necrotica, Acne rosacea, Baby acne, Excoriated acne, Halogen acne, Pseudofolliculitis barbae (Acne keloidalis nuchae) etc.
Acne vulgaris (or cystic acne) is a common human skin disease, characterized by areas of skin with seborrhea (scaly red skin), comedones (blackheads and whiteheads), papules (pinheads), pustules (pimples), nodules (large papules) and possibly scarring.
Acne affects mostly skin with the densest population of sebaceous follicles; these areas include the face, the upper part of the chest, and the back. Severe acne is inflammatory, but acne can also manifest in noninflammatory forms.
Acne develops as a result of blockages in follicles.
Hyperkeratinization and formation of a plug of keratin and sebum (a microcomedo) is the earliest change.
Enlargement of sebaceous glands and an increase in sebum production occur with increased androgen (DHEA-S) production at adrenarche.
The microcomedo may enlarge to form an open comedone (blackhead) or closed comedone (milia). Comedones are the direct result of sebaceous glands' becoming clogged with sebum, a naturally occurring oil, and dead skin cells.
In these conditions, the naturally occurring anaerobic bacterium Propionibacterium acnes can cause inflammation, leading to inflammatory lesions (papules, infected pustules, or nodules) in the dermis around the microcomedo or comedone, which results in redness and may result in scarring or hyperpigmentation.
There are multiple grading scales for grading the severity of acne vulgaris, three of these being:
Leeds acne grading technique: Counts and categorises lesions into inflammatory and non-inflammatory (ranges from 0–10).
Cook's acne grading scale: Uses photographs to grade severity from 0 to 8 (0 being the least severe and 8 being the most severe).
Pillsbury scale: Simply classifies the severity of the acne from 1 (least severe) to 4 (most severe).
Burtons scale: Clasification by severity from 1 to 6 (most severe).