The disease can begin around puberty but may not start until the late teens. Women often report they did not develop acne until after age of 25. Many people improve during the summer months with sun exposure but others get worse.
Diet may be implicated. For years patients have claimed that chocolate causes activity. Members of primitive societies have a low incidence of acne. They typically have a diet that contains no processed foods. They eat low glycemic foods such as fruits, vegetables and meat or fish. Milk and milk products should also be avoided.
Stress has also been implicated. College students often report flaring of disease at that time of final examinations.
Genetic factors have not been defined. Women with polycystic ovarian syndrome have a higher incidence of acne.