How long does it take for the erythema of lupus erythematosus to fade? If standard treatment is given, such as hormones, hydroxychloroquine to remove the rash, etc., the red rash usually appears to slowly fade in color in about 1 month. If the rash involves the dermis, there may be lifelong hyperpigmentation, and then it may become a pale, old erythema. Therefore, it depends on the thickness of the rash to determine whether it will completely disappear. But in any case, with the remission of the erythema, the color is significantly less than before, so you should have confidence in the erythema, and the effect is generally very good with standard treatment.