Four rather unusual and rare diseases are now being grouped together by medical investigators as a result of information derived from recent research. Their names, which are little known to the public, are polyarteritis nodosa, diffuse lupus erythematosus, scleroderma, and dermatomyositis. They resemble each other in that all of them represent disturbances of connective tissue in the body, in contrast to glandular tissue or surface secreting tissue.
The connective tissue of the body includes what is elastic and the material between the cells. Sometimes tumors consist almost wholly of connective or fibrous tissue. The walls of blood vessels contain much tissue of this type.
Now the big fact which developed during 1950 about these conditions is that all of them are benefited at least temporarily by use of ACTH or Cortisone. All of them resemble also the reactions that occur in tissues in response to hypersensitivity or allergy. Arthritis, which also responds to the drugs mentioned, occurs commonly in connection with each of these diseases.