This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
I have mentioned the external use of iodine in the treatment of this disease (v. p. 81), and there is some evidence in favor of its internal employment. Thus, Mr. Gay records cases of lupus affecting the face - in one man for seven years, in a woman for twenty years - which yet got well under 1/2-dr. doses of iodide of potassium (Medical Times, ii., 1871). There was no obtainable history or distinct evidence of syphilis, though one cannot but suspect a syphilitic taint in such cases. I have never known iodides cure ordinary lupus, nor is it a common experience. Dr. Mackey has noted two cases, in one of which the nose was affected, in the other the nose and scalp; ulceration was deep, indolent, and slowly progressive, in spite of caustic treatment; discharge was but slight, crusts formed at the edges, and the cases resembled true lupus, except that there were no tubercles, and the patients (men) were between forty and fifty years of age when the sores commenced. Both recovered quickly under the influence of iodide of potassium and mercurial lotions; but, although there was no history of syphilis, the probability remains in favor of its existence in similar cases.