There is no clear definition of mild lupus erythematosus. A common understanding of mild lupus erythematosus is that the symptoms are considered mild and some laboratory results, including those reflecting disease activity, such as blood sedimentation, C-reactive protein, complement and immunoglobulin, are not clearly elevated, suggesting that the disease is not clearly progressing. There was also no particularly numerous or severe organ involvement, such as hematologic involvement or renal involvement with renal insufficiency. In addition, there is no neurological manifestation of lupus erythematosus, so the above-mentioned manifestations are considered to be relatively mild lupus erythematosus. However, there is an evaluation index for lupus erythematosus called the SLEDAI score, which often evaluates the activity of lupus erythematosus. If the patient is considered to have mild symptoms, but the patient’s condition is judged to be more active in a comprehensive manner, it should also be taken seriously.