The connection between lupus and tubercle has often been noted. Especially in lupus of the face have the giant cells been found which are considered characteriitic and specific of tubercle.
The differential diagnosis lies between eczema, herpes circinatus, leprosy, cancer, and certain syphilitic ulcerations (the phagedenic chancre, the tubercular ulcerating syphilides, and sclerosing syphilitic edema of the vulva). Eczema and herpes run an entirely different course and remain superficial. Time makes the differential diagnosis. The same is true of cancer, even if at first glance the diagnosis is not made. We very rarely see leprosy at all. Tubercles have a different appearance, being dark or black, and they are not painful. Syphilitic ulcerations are clearly to be differentiated by the results of specific treatment.
The internal remedies recommended in the treatment of lupus are mainly used on the assumption that the affection is dependent on a scrofulous taint. These remedies are iodide of potash, mineral waters containing iodine, the iodide of iron, cod-liver oil, arsenic, and the like. It is questionable if without energetic local treatment these drugs are of any avail. In case syphilis is suspected the usual remedies are, of course, indicated.
Lupus is apparently of an infectious nature, remaining for some time localized, and therefore it is in particular essential that all the diseased process possible should be removed. All means to this end have been advocated. E. Martin uses the fuming nitric acid, the patient being chloroformed. He first applies cotton dipped in nitric acid for a few minutes, and then ice compresses to relieve the pain. When the slough has separated he makes a second application of nitric acid, 1 to 500. At the end of a month the surface is covered with healthy granulations and cicatrization has begun at the margins. Huguier recommends arsenic; G. Veit, caustic potass; Guillaumet, sulphuric acid. G. Veit applies the stick of caustic potass to the bottom of the nodule as far as the sound tissue. G Hfiter advocates the use of injections of phonic acid, Cregny poultices of a five per cent. solution of chloral hydrate every day, whereby a case was cured at the end of two years. It is a question here whether the cure was not spontaneous. Where hypertrophy is present as the result of lupus we should resort at once to excision, especially since Huguier and Nelaton have thus obtained good results.