Acne appears in the form of lesions on the skin when the pore opening, called the infundibulum due to its funnel shape, is blocked.
Types of lesions include:
- Open comedones (blackheads): appearing black or dark brown to the eye, these are follicles whose infundibulum are clogged with skin cells, sebum and melanin that have oxidized when exposed to air. Some cosmetic ingredients that are easily oxidized or cause keratinocytes to be retained in the infundibulum can also add to this condition. Open comedones are often thought of as the only non-inflammatory lesions of acne. However, it is now known that neutrophils, a class of white cell of the immune system, surround the microcomedone as it forms in the mid-infundibulum, causing inflammation as they form a first line of defense.
- Closed comedones (whiteheads): appearing as small white bumps due to swelling that occurs from inflammation and pus formation, causing the pore to narrow.
- Papules: appearing as small, red and inflamed lesions that are tender to the touch. Although they are filled with pus, the telltale white head is not visible. Unless treated, papules usually graduate to pustules.
- Pustules (pimples): appearing as larger papules crowned by white or yellow heads due to the amount of pus in the pore.
- Nodules: appearing only when pore walls, weakened by hyaluronidase, explode due to pressure caused by the amount of pus in the pore. These are usually larger, hard lesions due to pus leaking into local tissue.
- Cysts (aka: cystic acne): appearing when weak pore walls ‘heal’ and pus is no longer able to clear through the pore opening. Nodules are encapsulated below the skin’s surface, forming ‘cystic acne’.
Typically, acne is separated into four stages according to the lesions that are present.
Stage 1: Open and closed comedones and occasional papules or pustules.
Stage 2: All of the above, with more frequent or continuous appearance of papules and pustules.
Stage 3: Stage 2 accompanied by nodules.
Stage 4: Stage 3 accompanied by cysts.
While an esthetician skilled in working with acne can help clear Stages 1 thru 3, it is best to see a dermatologist if Stage 4 is present or if your esthetician is unable to clear your acne.
