Lichen sclerosus premenarche: autoimmunity and immunogenetics.

Lichen sclerosus is among the most frequently seen paediatric vulval disorders. In adults a strong association between lichen sclerosus and autoimmune diseases, and also with HLA class II locus DQ7, has been well demonstrated in women and a weaker association in men. These associations have not previously been studied in children, although in other autoimmune diseases, the HLA associations have been strongest in children. We performed HLA tissue typing and looked for autoimmune associations in a group of 30 children with vulval lichen sclerosus. HLA DQ7 was present in 66% of female children with lichen sclerosus compared with 31% in controls. Previous studies reported DQ7 in 51% of adult female patients and 45% of male patients. Sixteen per cent of the children were homozygous for DQ7 as opposed to 5% of controls. In the childhood group, only 4% had another autoimmune disease, but 56% of their parents or grandparents did. Age differences make comparison difficult, but the family history of autoimmunity appears to be strong in the early-onset group, in addition to the stronger association with DQ7.