In 1868, Hebra1 described under the term pityriasis rubra a rare disease, which had as its essential features deep red coloration and bran-like scaling involving the greater part or all of the cutaneous surface. Hebra's original description was modified and enlarged by Kaposi2 and Jadassohn,3 who gave us the present conception of the disease.
The cases described by Hebra were well advanced when first observed, but Kaposi saw two cases in the early stages of the disease, which began as redness and scaling in the regions of the flexures. When the disease is once established, it remains as it is from beginning to end without changing its character. The skin does not show infiltration or weeping, and papules, pustules or vesicles are not formed. The subjective symptoms consist of slight itching and chilliness.
The disease is essentially chronic in its course, lasting many years. As a result