Systemic Lupus Erythematosus and Related Diseases: Clinical Features

This chapter discusses systemic lupus erythematosus (SLE), epidemiology, immunopathogenesis, clinical presentation, diagnosis, autoantibodies, differential diagnosis, disease course, and treatment. SLE is the classic multisystem autoimmune disease. It occurs more frequently in women, with a 9:1 ratio. Multiple environmental factors contribute to the pathogenesis of SLE. Ultraviolet radiation is the best understood, leading to the exposure of Ro on the surface of keratinocytes. Other environmental triggers of SLE include certain drugs. The hallmark of SLE is the production of autoantibodies by B cells. Furthermore, The American College of Rheumatology has devised classification criteria that require the presence of four of the following eleven to “classify” SLE: malar rash, discoid rash, photosensitivity, oral ulcers, arthritis, serositis, renal disorder, neurologic disorder, hematologic disorder, immunologic disorder, and positive antinuclear antibodies (ANA). Treatment is determined by organ involvement. Photosensitive rashes are treated by sun avoidance, sun block, and by hydroxychloroquine, an antimalarial drug with an immunomodulating effect.