DIFFERENTIAL DIAGNOSIS OF PARAPSORIASIS

Abstract

Occasion may arise when nothing is more difficult in dermatology than a differentiation between parapsoriasis and allied conditions which are similar both clinically and histologically. About forty years has passed since Brocq united under the name "parapsoriasis" a group of diseases belonging to the class of chronic maculopapular, erythematous and scaly eruptions which have no effect on the general health and which last without benefit from treatment over a long period. These eruptions had been described by different observers in different countries. The same eruption has been given a variety of names, and in a great many instances the early stages of diseases well known at that time were confused with these new and less well known conditions. The original clinical and histologic descriptions (even if under different and confusing names) pictured by the early students of this subject, such as Jadassohn,¹ Neisser,² Juliusberg,³ Pinkus,⁴ J.