I have been able to demonstrate in the limited number of trials I have been able to do that reduction of the excess oil in these areas significantly reduces the intensity of the urge to pull from these areas. The underlying cause, at least initially, for this overactivity is likely systemic. The sebaceous glands respond to gonadotropic, thyroid, and other hormones present in the blood.
Adolescents develop oily skin due to high levels of testosterone and estrogen.
It is also possible the sebaceous glands may also trigger off the hormones and other substances in the food we eat, which may explain John's trigger food phenomenon. Aside from judicious dietary changes, dealing with the hot spots on a systemic level is best left to the medical professionals. Being a good state of overall health often lessens the incidence and severity of many disorders when they do occur. So it is good idea to do those things such as exercise, eating a healthy balanced diet, and seeing your doctor for checkups on a regular basis which maintain that state of overall wellness. Remove any possible sources of allergies or irritation.