Boston Medical and Surgical Journal
1916, Volume 174, number 14, page 517
William Pearce Coues, M.D.
To suspect syphilis as a common cause of this painful complaint would be manifestly an exaggeration of the possibilities. At the same time it is wise to keep an open mind on the subject.
The occurrence of this symptom in obscure cases, which later I have proved to be unrecognized syphilis, bus happened a sufficient number of times to make the matter more than a coincidence in my opinion. Unexplained "neurasthenia" has of late been proved to be unrecognized syphilis more than once. It has been found that patients suffering with pain In the back of the head and at the "base of the brain," seemingly typical neurasthenics, are really suffering from high vertebral syphilis.
The probable explanation of these cases of coccygodynia is similar; they have a definite pathologic process to account for their pain. The coccyx is a "bone of stress," similar to the tibia, and we are dealing with a true osteo-periostitis, often started up in these cases by a fall or blow, so often the history in specific bone troubles. Combined rectal and external palpation gives bone pain, which can be compared in every way with that of the pain of pressure over specific tibiae.