Acne is usually caused by accumulation of natural oil on a hair follicle which leads to clogging up. This results in formation of what is called a comedo. Accumulation of more oil leads to the comedo becoming larger, inflaming the skin around the area and forming a pimple.

So what are the different types of acne that we know of? They are listed below.

Nodular or Cystic Acne
A Nodular or cystic acne is an inflamed, pus-filled lesion lodged deep within the skin. It forms when the contents of a comedo spills into the surrounding skin causing the immune system to respond by producing pus. Severe forms of this acne may persist for weeks eventually causing the lesions to harden into cysts. These cysts leave deep scars on the skin.

Blackhead Acne
A blackhead also known as an open comedo is a form of inflammatory acne. It forms when a plug enlargens, pushing through the surface of the skin. The dark appearance is as a result of melanin, the dark pigment of the skin.

Papule Acne
A papule is a small, firm, pink bump which can be tender to touch.It is considered as an intermediary step between non-inflammatory and inflammatory acne.

Pustles
Pustules are more like papules since they are small and round lesions. However they differ in that they are clearly inflamed and visibly contain pus. They are characterized by a red base and a yellowish or white center full of pus. They don't contain a great deal of bacteria but are inflammed due to chemical irritation from sebum components.

Acne conglobata, a rare form of inflammatory acne, forms primarily on the back, buttocks, and chest. It is characterized by pustules and nodules, and severe bacterial infection may ensue.

Acne cosmetica is caused from topical cosmetic products and is inflammatory.It's usually found on the cheek,chin and forehead.It's characterized by a small pink bump.This condition may develop over the course of a few weeks or months but usually doesn't leave behind scars.The trick is to find out which topical products are bringing about this acne on you and immediately stop using them.

Once you determine the kind of acne you have, a suitable treatment can then be found for it.