SLE usually can be distinguished if there are skin lesions on light-exposed areas, hair loss, oral and nasal mucosal lesions, absence of joint erosions in even long-standing arthritis, joint fluid that often has white blood cell counts < 2000 / mcL (2.0 x10 9 / L) (predominantly mononuclear cells), antibodies to double-stranded DNA, renal disease, and low serum complement levels.