Why does Acne Occur During Menstrual Cycle?

Why, when you are starting your monthly cycle, do you get acne on your face or your back?

Acne can result from an imbalance of hormones. In puberty, with the change in sex hormones, the oil producing glands in the skin become more active, making the skin of the face, back and chest (where there are the most oil glands) more oily. The hair follicles containing these oil glands can become clogged with excess oil, causing inflammation and infection. The sex hormones change during the menstrual cycle. If the hormones are out of balance, especially when testosterone is high, this same reaction can occur. Hormone related acne is common with women who experience premenstrual syndrome or who are taking birth control pills.
Good skin care, including gentle washing with a pH balanced cleanser three times a day, helps to keep the glands clean. Avoid creams that contain vaseline, which promotes clogging the skin glands.
Chasteberry (Vitex agnus castus) helps to balance sex hormones. When taken for at least 3 months, chasteberry has proven effective in hormone-related acne. Chasteberry should not be taken with hormone drugs.
A diet that includes junk foods, fried foods and sugars exacerbates the problem, as does constipation and liver problems. In these cases, there is a build up of toxins which can eliminate through the skin.