summaryA study of autoimmune related phenomena in 350 women with histologically confirmed lichen sclerosus et atrophicus revealed that 21.5% had one or more autoimmune related diseases, 21% had one or more first degree relatives with an autoimmune‐related disease, 42% had an autoantibody at a titre>1:20, and 59.5% had one or more of these autoimmune‐relateda phenomena. No statistically significant differences in the natural history of lichen sclerosus et atrophicus were demonstrated between those patients with autoimmune‐related phenomena and those wi