This results in a build-up of oil and bacteria, which ruptures the skin. Pimples and blackheads are manifestations of secondary infections. A blackhead or whitehead appears when dust, dirt or sebum blocks a skin pore. The waxy plug that blocks the pore is called a comedo. This forms a blackhead when it is exposed to air.
Oxidation turns the head of the comedo black.
If it is not open to the air, a whitehead is formed. At the time of puberty, there is a slight hormonal imbalance that is caused by a girl s ovaries and adrenal glands secreting extra androgens, thus increasing the ratio of androgens to estrogen. Stress is also a factor to be considered as during times of stress, our bodies release additional androgens. Acne can also be linked to a woman s menstrual cycle. Some women find that they break out into pimples just before the onset of their menses.