In general acne are the consequences of blockage of the follicles present in the skin. There may be many reasons:-
1. Hormonal – stressful hormonal conditions like menstrual cycles and puberty may be one of the major cause of acne. In the puberty, the male sex organ is responsible for the blockage of the follicles. Similar is the with the case of estrogen hormone that on the onset of menarche in females.
2. Genetics – it has been seen that there are certain tendencies in the families that can lead to the cause of acne.
3. Psychological – In the recent times studies have shown that there is a connection between stress and acne. It has been observed also that acne erupts more in stress.
4. Infections – Propionibacterium acnes and Staphylococcus epidermis has been linked with the acne
5. Diet – Diet that is rich in high levels of glycemic has been linked with development of acne.
Home Remedies for Acne and Home Remedies for Body Rash and Acne Signs and symptoms from http://herbalcureindia.com/lifestyle/acne