LUPUS erythematosus discoides is a chronic inflammatory dermatosis, and the remedies which have been used in its treatment are legion. Nevertheless, the results of treatment are still unsatisfactory. Sequeira, Ingram and Brain1 state that 30 per cent of the patients are cured, 30 per cent improved and 40 per cent unchanged after treatment. Sutton and Sutton,2 discussing the prognosis of the disease, state that this should always be guarded and that the disease is erratic in its course, with occasional recurrences and relapses common. They also state that new patches sometimes develop and older ones extend despite the employment of approved therapeutic measures. No one has yet been able to forecast, however, which cases will and which cases will not react to treatment. I will describe in this article a simple method of obtaining an early and reliable prognosis in cases of this capricious disease. It will also