Paediatric-onset systemic lupus erythematosus.

Paediatric-onset systemic lupus erythematosus (SLE) is usually more severe than its adult counterpart. In particular, there is a higher incidence of renal and central nervous system involvement. Specific measures to assess disease activity and damage have been implemented. The disease is very rare before the fifth birthday and therefore the onset of an SLE picture in the first years of life should lead to the suspicion of the presence of one of the rare monogenic diseases that causes SLE or of one of those congenital diseases that has been showed to be closely associated with the SLE.