There are seven main factors behind an outbreak of facial or body acne.

Genetics. If your mum or dad had acne as a teenager, there's a good chance you will too.

Hormones. During adolescence, hormones called androgens become active and stimulate oil glands in your skin, increasing oil production. This, in turn, clogs pores, causing pimples and blackheads. Hormonal changes that occur during your period or when you start or stop taking birth control pills can also cause an acne flare-up. In some cases, however, certain birth control pills are prescribed as a treatment for acne.

Stress. Although stress doesn't actually cause acne, it will potentially aggravate this or any other skin condition you may have.

Diet. Dermatologists aren't sure whether or not what we eat plays a critical role in acne. Some experts do believe, however, that food allergies can trigger acne outbreaks.

Washing your face too often. This can aggravate the skin, causing acne to occur.

Using greasy skin care products and oily cosmetics. Any product that clogs oil ducts may cause acne.

Medications. Acne can be a side effect of some drugs, including barbiturates, seizure medication and steroids.

Body acne

Body acne is common in adults and teens, and it appears mostly on the chest, back and buttocks. Like facial acne, hormones can cause these blemishes. However, other factors can induce acne lesions on the body.

Perspiration and tight-fitting clothing are two of the most common culprits, which explains why many physically active women are plagued by body acne. Most popular athletic clothing made with fabrics like Spandex isn't breathable. As a result, it can trap perspiration against the skin, which then mixes with surface oils. The result is a filmy layer that clogs pores and causes blemishes; these can range from whiteheads to more severe lesions called papules and pustules.

Treatments for body acne are similar to those for facial acne, but body acne can be hard to reach when applying medicine, and as a result, hard to treat. Body skin is also thicker than facial skin, and body blemishes are constantly exposed to friction from clothing, which can irritate and make acne worse. To keep acne under control, wash daily with a salicylic-acid-based cleanser and shower as soon as possible after perspiring. Wipe the affected area with a benzoyl peroxide or salicylic acid pad, and follow with an alpha hydroxy acid-based body moisturiser if needed (this will help exfoliate skin while preventing it from drying out). Use a salicylic acid or benzoyl peroxide spot treatment on individual pimples at night.

Stubborn acne is usually treated with a topical retinoid such as Retin-A or Retinova, or a course of oral antibiotics such as Tetracycline, Minocycline or Erythomycin. It will usually take anywhere from a week to a couple of months to see results. As a last resort, Roaccutane is used in severe cases of acne.