A clinical and histologic study of pityriasis rosea during the last 5-year period

Abstract

Background: Pityriasis rosea is an acute inflammatory dermatosis with an unproven etiology. The typical clinical feature consists of an initial, single herald patch followed by the development of smaller, disseminated, papulosquamous and ovoid macules. Objective: The aim of this study was to evaluate the clinical manifestations of pityriasis rosea. Methods: We examined a total of 101 patients with pityriasis rosea who visited the Department of Dermatology in Chung-Ang University Medical Center from March of 2005 to February of 2010. Results: There were 1.53 times more women (61 patients) than men (40 patients) among the study subjects. The age of onset varied from 4 years to 71 years with a mean age of 28.7 years and 60% of the cases were 20 years to 39 years old. The percentage of seasonal variation was 34% in winter, 24% in summer, 22% in spring and 21% in autumn. A herald patch was found in 43% and the main predilection sites were the trunk and the thigh. Secondary eruptions could be classified into the macular type (67%), papular type (30%), urticarial type (2%) and purpuric type (1%). They appeared on the back, the chest, the abdomen, the upper arms, the thighs, the neck, the forearm, the lower legs, the face, the hands and the feet. The histopathological findings of all the types of lesions were focal parakeratosis, intraepidermal vesicles and papillary dermal edema. As compared to the macular type, hyperkeratosis, parakeratosis and exocytosis of lymphocytes were less commonly observed in the papular type. Conclusion: Most of the study results were compatible with those of other previous studies. However, the number of patients with papular type pityriasis rosea was currently increasing.