The vehicle (placebo) is an ointment that does not have any active medical ingredients. Sometimes a patient’s condition improves even when no active medication is given. Therefore, the vehicle is used to evaluate the effects of the investigational ointment. Whether or not you (or your teenager) receives the vehicle, you will be monitored closely during the study. Neither you nor the study team will know the treatment assignment. However, in a case of emergency, the study doctor can quickly find out if you are receiving the study ointment or vehicle.