The 1982 ACR classification criteria have become de facto diagnostic criteria for systemic lupus erythematosus (SLE), but a review of the criteria is necessary to include recent diagnostic tests. The criteria were not developed with the help of dermatologists, and assign too much weight to the skin as one expression of a multiorgan disease. Consequently, patients with skin diseases are classified as SLE based mostly on skin symptoms. We discuss specific problems with each dermatologic criterion, but changes must await a new study. We suggest the following guidelines for such a study, aimed at revision of the criteria. 1) The SLE patient group should be recruited in part by dermatologists. 2) The study should evaluate an appropriate international ethnic/racial mix, including late onset SLE as well as pediatric patients. 3) All patients should have current laboratory and clinical evaluations, as suggested in the paper, to assure the criteria can be up-to-date. This includes anti-SS-A and anti-SS-B antibodies and skin biopsies for suspected cutaneous lupus erythematosus except for nonscarring alopecia and oral ulcers. 4) The study should be based on a series of transparent power calculations. 5) The control groups should represent relevant differential diagnoses in numbers large enough to assess diagnostic problems that might be specific to these differential diagnoses. In order to demonstrate specificity of the criteria with a 95% confidence interval between 90 and 100%, each control group of the above should have at least 73 patients.