What is a second edition (revised), in contrast with a third edition? Dr Dubois explains, in this second edition (revised) of his comprehensive monograph Lupus Erythematosus. The second edition, completed in 1974, was so successful that a second printing was needed in 1976. Rather than reprint the text as it stood in 1974, Dubois and his contributors added 200 new references (out of 3,000), and put the new reference numbers in the index. Thus it is easy, for example, to spot an important new publication on lupus induced by hydralazine hydrochloride. There are some other minor changes in format, but nothing really noteworthy except for the new references. Dubois has indeed found a way to update a second printing without much expense or trouble. The changes, however, do not warrant discarding the 1974 second edition for the 1976 update.