Hi, Acne is caused commonly in teenagers and young adults as a result of the hormonal changes that occur post puberty and its effect on the skin. it is secondarily affected by microbial colonisation and also affecetd but lifestyle and food habits. See a qualified dermatologist near you and seek deatiled evalaution and treamtent. Alternatively you could contact me with your pictures on practo direct consult. Warm regards, Dr Govind Suresh Mittal, Bengaluru.