develops when excess sebum, skin cells, and bacteria accumulate in your pores. While exact cause of acne is not identified, this is often associated with hormone changes,medication side effect, family history of acne, stress. products used on hair and skin and even from underlying medical conditions. While irritants may also be a factor, further evaluation may need to be done. Continue your facial regimen and avoid too much sun exposure, touching your face and even popping your acne.