Light- and electron-microscopic findings in lichen sclerosus of the vulva during etretinate treatment.

Fifteen women with lichen sclerosus (LS) of the vulva were treated for 3 months with 0.6 mg/kg of etretinate. The clinical response was good in 11/15 of the patients and, in agreement with this, light microscopy showed decreasing atrophy and hyperkeratosis together with subsiding inflammatory changes. However, orcein staining demonstrated that even after etretinate treatment, elastic fibers were still absent in the upper dermis with only few fibers being detectable in some specimens. Conventional electron microscopy and immunoelectron microscopy were used to examine these changes more in detail. Antiserum to the microfibrillar part of the elastic fibers confirmed that only remnants of microfibrillar coat persisted in the upper dermis and that deeper in the dermis, elastic fibers were porous and fragmented. These findings demonstrate that despite the normalization of clinical and certain histological parameters during etretinate treatment, the initial elastic fiber damage persists both at the light- and electronmicroscopic levels.