The author studied the significance of the hot-spring bathing treatment upon rheumatic disease. Excreted urinary 17KS was measured for this purpose and Nomin-no-yu (sulfur spring) and thermal water of the University Hospital (sulfated spring), were employed. The results were as follows:
1) Compared with healthy persons, the value of excreted urinary 17KS of rheumatoid arthritis patients was low. Dividing rheumatoid arthritis patients into two groups, namely, those suffering from less than a year and those more than a year, it was found that no difference was observable in the values of urinary 17KS secretion between the former group and healthy persons and that the value was low in the latter group. Therefore it was postulated that the pituitary adrenocortical function might be impaired due to the prolonged process of rheumatic disease.
2) Hot-spring bathing treatment increased excreted urinary 17KS in rheumatoid arthritis patients. The increase in urinary 17KS excretion reached a maximum 7 days after the initiation of the treatment. After this it gradually decreased, though the increase was still observable 14 days after the initiation. It might be due to the difference in properties between Nomin-no-yu and thermal water of the University Hospital that the increase in excreted urinary 17KS was higher and the duration of the increase was longer in the former than the latter. It seems that the incerase was mainly due to vitalization of the pituitary adrenocortical function by nonspecific stimulation, because the difference was observed in individual reactions against synthetic stimulating action of hot-spring bathing.
3) The increase in excreted urinary 17KS caused by hot-spring bathing was less in rheumatoid arthritis patients than in healthy persons, In a very few cases of rheumatoid arthritis, hardly any increase could be observed; there were some cases in which a decrease in excreted urinary 17KS was observed. An inference can be made from the findings mentioned above that the pituitary adrenocortical function is generally deteriorated in rheumatoid arthritis patients.
4) Hot-spring bathing will increase excreted urinary 17KS in rheumatoid arthritis patients, if it is used in combination with aspirin therapy in which a large quantity of aspirin is used. Where this combined therapy was successful, a pronounced increase in excreted urinary 17KS was observed in rheumatoid arthritis patients. However, where the combined therapy was unsuccessful, the number of cases in which the increase was observed was almost equal to that in which the decrease was observed. These findings suggest that balneotherapy and aspirin therapy work mutually in the therapeutic treatment of rheumatic diseases.
5) In those cases of rheumatoid arthritis where hot-spring bathing was used in combination with prednisolone, excreted urinary 17KS decreased temporarily, but it tended to increase again a few days after the discontinuance of administration of prednisolone. There are many cases where a reduction in the amount of prednisolone to be administered will cause the appearance of reactivation symptom of rheumatoid arthritis, but it is anticipated that hot-spring bathing can prevent it to some extent, judging from the changes in excreted urinary 17KS caused by balneotherapy. Further examination is needed for any definite conclusion.

The author studied the effect of hot-spring bathing on the pituitary adrenocortical function of rheumatoid arthritis patients by means of Thorn's test, employing Nomin-no-yu and thermal water of the University Hospital (sulfated spring), and obtained the following conclusion.
1) Unusual count of eosinocytes can be found among persons who are apparently healthy, and who cannot be the good subject of Thorn's test. Such unusual cases were excluded. Thorn's test revealed that the reduction of eosinocytes were more than -50.0% (an average of -55.2%) in most of healthy persons (11 out of 15 cases).
2) The number of eosinocytes in blood of almost all healthy persons decreased through hot-spring bathing, showing a decrease of 15.8% on an average, which shows that hot-spring bathing has an action similar to that of ACTH. Such a phenomenon will be more pronounced with the initiation of balneotherapy, showing the rate of decrease as high as 35.3% on an average. Namely, the action of hot-spring bathing similar to that of ACTH tends to be intensified with the initiation of balneotherapy.
3) Thorn's test in rheumatoid arthritis patients revealed that the number of those in whom the rate of decrease was more than 50.0% was about equal to that of those in whom the rate of decrease was less than 50.0%, showing an average rate of 50.8%, which is almost similar to that of the healthy subject. In the case of those who had been suffering from rheumatoid arthritis more than a year, both the stage of progress of symptoms (stage) and the class of dysfunction (class) were high, and in such cases, the rate of eosinocyte decrease in Thorn's test was clearly less and the lowering of pituitary adrenocortical function was also observable.
4) It was clearly observed that Thorn's test on rheumatoid patients, when performed together with balneotherapy, showed an increase of the rate of eosinocyte decrease in the most of cases. At the same time it also increased generally the excreted urinary 17KS in those patients. Balneotherapy performed in combination with medicamenttherapy increased the rate of eosinocyte decrease in most cases. The increase was especially clear in those in whom the rate of decrease had been less than 50.0% before the initiation of balneotherapy. However, improvements of Thorn's test did not necessarily go in parallel with therapeutic effect and improvement in symptoms.
5) These findings show that the changes observable in Thorn's test provide us with a guide in balneotherapy of rheumatoid arthritis and are useful in explaining the balnectherapeutic effect in rheumatic disease.