Ultrastructural changes in sebaceous glands following treatment of cystic acne with isotretinoin.

Following 20 weeks of treatment with isotretinoin, sebaceous glands in patients with cystic acne shrank in size. The cells remaining in the sebaceous lobules were mainly mature lipid-filled cells, with some undifferentiated cells still present at the periphery. The ultrastructure of the glands 8 weeks after cessation of treatment was directly related to the drug dose given each patient. The larger the dose, the slower the return to pretreatment morphology. In those patients given a lower dose, most of the glands observed 2 months after treatment was stopped were similar in size to those seen prior to treatment.