PITYRIASIS ROSEA

Abstract

Pityriasis rosea is not the restricted disease that it is commonly depicted to be in most textbooks on dermatology. Gibert's¹brief description of pityriasis rosea in 1860 remains an accurate description of only one form of the disease,²the macular variety. He did not recognize the circinate variety. In 1862, Bazin³directed attention to this common variety of the disease. Gibert considered his pityriasis rosea an intermediate variety between pityriasis simplex and pityriasis rubra. The eruption described by Vidal⁴in 1882 as pitryiasis circiné et marginé is generally accepted now to be an anomalous variety of pityriasis rosea. Vidal regarded his pityriasis circiné et marginé as distinct from pityriasis rosea, and enumerated its differential features from that disease. The notable differential feature was the long duration, about six months. In the light of present knowledge, that feature cannot be regarded as negativing the diagnosis of pityriasis