What is lupus? What is not lupus?

Present understanding suggests that lupus reflects a spectrum of syndromes that share many clinical, inflammatory, and immunologic features. Those patients not fulfilling criteria for systemic lupus erythematosus (SLE) do not seem to evolve frequently to classic SLE, tend to have a good prognosis, and may be managed conservatively. This is important for clinical management. Whether this pertains to etiopathogenesis is speculative and will await information not yet available.