Different types of Acne
Acne Vulgaris
Acne vulgaris is the most common type and involves the initial development of comedones which are blackheads and/or white heads.
Acne Conglobata
Acne conglobata is a chronic and severe form which is characterized by deep abscesses, inflammation and widespread damage to the skin.
Acne Fulminans
Acne fulminans is characterized by a sudden occurrence of highly debilitating inflammation.
Nodulocystic Acne
Nodulocystic acne occus in isolation or in thick clusters on the face, neck, scalp, back, chest and shoulders.
Read more about Acne and types of acne at Wikipedia