Acne can occur on your face, neck, shoulders, chest, back, and upper arms.
Some factors which may cause acne include:
- Propionibacterium acnes (P. acnes), a common skin flora, metabolizes sebum into free fatty acid which may irritate the skin around sebaceous duct.
- Sebaceous glands (oil glands) release a fatty substance, sebum, to the surface of the skin. You will notice acne usually occurs on the areas of your body with the most oil glands, e.g., the face, back, and chest. Those with excess oil production are prone to acne outbreaks.
- Hormonal changes caused by puberty can worsen acne.
- Those who have a hereditary tendency to overproduce dead skin cells may lead to more clogged pores, which can cause acne.
- Diet: New studies have not shown significant connection between diet and acne. Some dermatologists may also deny the connection. However, if you have a history of acne outbreaks causing by certain type of diet, it is recommended to avoid that type of food.
- Other factors, such as stress and lack of sleep, may increase risk of acne outbreaks. Certain medication, such as corticosteroid, lithium, INH, Iodide, bromide, Dilantin, vitamin B12, may cause acne. There are also reports of some chemical agents, cosmetics, and soaps which may irritate the skin and increase risk of acne outbreaks.