Alterations in fibrillin as well as collagens I and III and elastin occur in vulval lichen sclerosus

Background The clinical features of lichen sclerosus, which include atrophy , scarring, fragility and tendency to form ecchymoses with only slight trau ma, suggest that there is an alteration in the extracellular matrix fibres that are responsible for the tensile strength of the dermis. However, the p recise nature of these changes is poorly understood. Methods Biopsies from 16 patients with untreated, histologically confirmed, vulval lichen sclerosus were examined immunohistochemically using polyclon al antibodies to collagens I and III and a monoclonal antibody to elastin. Twelve of the lichen sclerosus specimens were also stained with a monoclona l antibody to fibrillin. Normal vulva tissue and patients' uninvolved thigh were used as controls. Results In the lichen sclerosus specimens, collagens I and III stained with a more homogeneous pattern than in the control tissues. Reduced numbers of elastin fibres were seen in the zone of sclerosus in 15 of the 16 lichen s clerosus specimens. In the control tissue fibrillin fibres were seen as a f ine network of fibres in the upper dermis arranged at right angles to and i nserting into the basement membrane and forming a fine network throughout t he dermis. In the lichen sclerosus specimens, although fibrillin microfibri ls were still seen inserting at right angles into the basement membrane, be low this the fibrillin staining was reduced in the upper dermis in 11 of th e 12 lichen sclerosus specimens. The zone of reduced fibrillin staining was greatest in those specimens where the band of inflammation was deep in the dermis. Conclusions The distribution of collagens I and III, elastin and fibrillin are altered in lichen sclerosus and this is likely to contribute to the fra gility, scarring and atrophy seen clinically in lichen sclerosus.