[Capillaroscopy in rheumatoid arthritis]

Three capillaroscopic features to be found at the base of nails are recognizable in rheumatoid arthritis. This is in conjunction with the clinical picture, the biological data, and the course of development. In the first, the tissue is transparent, there are many small comma-shaped capillary loops; the second feature is characterized by extreme transparency, pale base and long "hair-pin" loops spread in treillis form over the venular plexus in slow, granular circulation. A third feature recalls from the start a state of collagenosis, because of the inhomogenous opacity of the tissue, the presence of capillary hemorrhage and the irregular appearance of the loops, often of the "megacapillary" variety (I.E. congenital capillary dilatation). This division into three categories determines the character prognosis and treatment. It corresponds histologically to "pulp" biopsy and to the region of glomie arterio-venous anastomosis. There is therefore a real rheumatoid histoangiopathy.