The most common type of acne is Acne Vulgaris which literally means ' common acne.' This type of acne can cause blackheads, whiteheads, papules, pustules, nodules and cysts.
Blackheads - Blackheads occur in partially blocked pores. Sebum (the substance which causes oily skin), dead cells, and bacteria are slowly draining to the surface of the skin and the black color is caused by the pigments in the skin being exposed to air. Blackheads can take a long time to clear up.
Whiteheads - Unlike blackheads, whiteheads are contained beneath the surface of the skin. They are caused by completely blocked pores which trap the sebum, dead cells, and bacteria.
Papules - These are small red bumps on the skin. They are tender and cause irritation, but it is important not to touch them or squeeze them. Doing so may cause scarring.
Pustules - Pustules are what most people call pimples or zits. They appear as a red circle with a white or yellow center.
Nodules - These are much larger than other forms of acne. They are hard lumps underneath the surface of the skin which can be painful and last for several months. This type of acne is particularly vulnerable to scarring, so it is advisable to have it treated by a dermatologist.
Cysts - Cysts are similar to nodules except that they are filled with pus. They are painful and likely to scar if untreated. Like nodules, they should be treated by a dermatologist.
Acne Conglobata - This is a relatively rare form of acne vulgaris but it is extremely disfiguring and can cause severe psychological as well as physical suffering. Large lesions form on the face, chest, back, buttocks, upper arms, and thighs and can be accompanied by numerous blackheads. It causes damage to the skin and permanent scarring. It is more common in males than females, and the condition can persist for several years.
Acne Fulminans - This is a sudden appearance of Acne Conglobata accompanied with a fever and aching of the joints. It is usually treated with oral steroids.
Gram-Negative Folliculitis - This condition may be caused by long-term treatment of acne with antibiotics. It is a bacterial infection which causes pustules and cysts.
Pyoderma Faciale - This type of acne only affects females usually between the ages of 20 and 40. It causes large painful pustules, nodules and cysts on the face and may leave permanent scarring. It most often occurs in women who have never experienced acne before and usually clears up within a year.