Functional naevi of the sebaceous gland

This  group includes  very uncommon conditions in which there are increased (or decreased) functional and structural  abnormalities   predominantly   of   the sebaceous element. Unilateral acne - a patient with  virtually unilateral acne on one side of the trunk.101 Investigations showed increased sebaceous lipogenesis on that side. It could be argued that the abnormal side was  the left side, which failed to  develop acne.