What is Acne?
Acne is the term for plugged pores (blackheads and whiteheads), pimples, and even deeper lumps (cysts or nodules) that occur on the face, neck, chest, back, shoulders and even the upper arms. Acne affects most teenagers to some extent. However, the disease is not restricted to any age group; adults in their 20s - even into their 40s - can get acne. While not a life threatening condition, acne can be upsetting and disfiguring. When severe, acne can lead to serious and permanent scarring. Even less severe cases can lead to scarring.
Types of Acne
When you read about acne or other skin diseases, you encounter words or phrases that may be confusing. For example, the words used to describe the lesions of acne—comedo, papule, pustule, nodule and cyst—are understandable only if you know each word's definition. It also is helpful to have a photo that is characteristic for each type of lesion.
Here is a brief summary of definitions of words used to describe acne, with accompanying photos. Let's begin, though, with the definition of lesion, an
Lesion—a physical change in body tissue caused by disease or injury. A lesion may be external (e.g., acne, skin cancer, psoriatic plaque, knife cut), or internal (e.g., lung cancer, atherosclerosis in a blood vessel, cirrhosis of the liver).
Thus, when you read about acne lesions you understand what is meant—a physical change in the skin caused by a disease process in the sebaceous follicle .
Acne lesions range in severity from comedones (blackheads and whiteheads) to nodules and cysts. Here is a brief definition of acne lesions:
Comedo (plural comedones)—A comedo is a sebaceous follicle plugged with sebum , dead cells from inside the sebaceous follicle, tiny hairs, and sometimes bacteria. When a comedo is open, it is commonly called a blackhead because the surface of the plug in the follicle has a blackish appearance. A closed comedo is commonly called a whitehead ; its appearance is that of a skin-colored or slightly inflamed "bump" in the skin. The whitehead differs in color from the blackhead because the opening of the plugged sebaceous follicle to the skin's surface is closed or very narrow, in contrast to the distended follicular opening of the blackhead. Neither blackheads nor whiteheads should be squeezed or picked open, unless extracted by a dermatologist under sterile conditions. Tissue injured by squeezing or picking can become infected by staphylococci, streptococci and other skin bacteria.