Dr. Shlomo Sprecher describes the publication of this responsum in his excellent article Mezizah be-Peh - Therapeutic Touch or Hippocratic Vestige? in Hakirah v. 3 as follows:
In fact, the Ḥatam Sofer’s original Responsum appeared in print only once―in early 1845―in the pages of the first issue of a Hebrew literary periodical issued in Vienna, entitled Kokhavei Yiẓḥak. Its editor, Mendel Stern, was a native of Pressburg and had served as a tutor in the Ḥatam Sofer’s household, instructing his children. This publication was not the usual kind of reading material favored by the disciples of the Ḥatam Sofer, and so it is not surprising that many 19th Century authorities could seriously doubt the veracity of this attribution. However, to continue to maintain these doubts or posit qualifications such as “hora’at sha’ah” given the state of information available today is simply wrong.Here is a picture of the recipient of the responsum, Rabbi Lazar Horowitz:
:
