The condition may be cosmetically undesirable to some patients. Blacks with a fair complexion have the lowest frequency of involvement. DPN also occurs among Asians, although the exact incidence is unknown. Females are affected more frequently than males. The incidence of DPN, as well as the number and size of individual lesions, increases with age.
Lesions usually begin during puberty.
They tend to increase steadily in number and size as the affected individual ages. Lesions occur mainly on the malar area of the face and forehead, although they may also be found on the neck, upper back and chest. A small percentage of patients have similar lesions on the upper trunk. Scaling, crusting and ulceration do not occur. DPN is thought to be caused by a nevoid developmental defect of the pilosebaceous follicle.