Acne

Acne is a dermatological condition characterized by one or more lesions on the surface of the skin. It is most commonly present in adolescence, but can form anytime during adulthood. Acne is not life-threatening, but when treated incorrectly can lead to permanent scarring. In most cases, the lesions are present on the face only. However, in more serious cases, the disease may also be present on the neck, chest, back, and arms, and cause a great deal of pain.

There are six different types of lesions: papule, comedo, pustule, macule, nodule, and cyst. Each type of lesions vary in severity, and knowing the difference will help determine the correct treatment.

Papules
Papule are completely solid and closed, causing small patches of bumps ranging from nearly invisible to approximately 5 millimeters in diameter. Papule start forming as a normal pimple, but turn into a papule due to a reaction in that specific cell.

Comedones
Comedones are commonly referred to as blackheads and whiteheads, and are the least severe types of acne. A comedo forms when residual skin oil, makeup, dirt, dead skin, and small hairs impact a sebaceous follicle and prevent the pore from functioning correctly. The result is a small impaction that is neither red nor painful. If the pore is open, the comedo will be dark in appearance and is thus called a blackhead. If the pore is closed, than the comedo is referred to as a whitehead, and is flesh-colored in appearance.

Pustules
Pustules, while similar in appearance to macules, are active infections of the skin that consists of dead skin cells and bacteria. These lesions are spherical in appearance and are filled with pus. Often reddish in color, pustules may be painful and will break open easily if scratched or bumped. Pustules will likely heal without other aid; however, some will develop into cysts.

Macules
A macule is the result of a healed acne lesion. It consists of a red flat patch of skin with a defined border, and may be present for up to several weeks before disappearing. Macules may appear like a grouping of inflamed pustules or psoriasis. New lesions may appear atop the macules of previous infections, and can lead to scarring if scratched open.

Nodules
Nodules are the natural progression of a papule. They appear very similar to papules, but are inflamed and penetrate deep into the skin. They may result in tissue damage and can lead to severe scarring. Pustules are often very painful; pustules are considered a severe form of acne, and can be difficult to cure.

Cysts
Usually occurring in conjunction with nodules, cysts are considered severe acne lesions and are usually very painful. They penetrate the skin deeply, and usually result in scarring. Filled with bacteria, dead skin cells, and white blood cells, cysts are often severely inflamed and almost always cause scarring. When a nodule and a cyst occur together, it is often referred to as nodulocystic. Nodulocystic conditions are often only treatable with isotretinoin.