THE NATURAL HISTORY OF PARAPSORIASIS EN PLAQUES (CHRONIC SUPERFICIAL DERMATITIS) AND PRERETICULOTIC POIKILODERMA

Summary.— The term parapsoriasis en plaques includes 2 quite unrelated conditions, one eczematous and benign, the other prereticulotic and potentially malignant. These 2 conditions are described and their features are compared in detail. In England, especially the south, the benign form is a good deal more common than the premalignant. The reason why parapsoriasis en plaques is regarded as a potentially serious disease is thus due largely to nomenclature, but also in part to the fact that, in the early stages of the classical Alibert form of mycosis fungoides and in prereticulotic poikiloderma, the appearances can closely simulate the benign type of parapsoriasis. Careful clinical observation and histological examination should, however, serve to distinguish between them.