Cutaneous lupus erythematosus and the association with systemic lupus erythematosus: a population-based cohort of 1088 patients in Sweden

This is the first nationwide epidemiological study on CLE. We found the incidence of CLE to be about equal to that of SLE, and found a higher short-term probability for receiving an additional diagnosis with SLE than previously described for CLE. Subsets other than DLE and SCLE were rarely reported in our system; an update of the ICD codes for this diagnostic group could increase reporting of these more unusual cases. Our study clarifies that monitoring and follow-up are called for in this patient group due to the risk for SLE, and underscores the need for clear criteria for risk assessment in the large group of patients with CLE who also fulfil criteria for SLE.