A Clinical and Histopathologic Study of Pityriasis Rubra Pilaris

Jeong, Jeung Tae; Kye, Young Chul; Kim, Soo Nam

Abstract

BACKGROUND: Pityriasis rubra pilaris (PRP)is a rare papulosquamous disorder of unknown etiology. Although the clinical and histopathologic features of PRP are relatively well known in western patients, there are few available studies in Korea.
OBJECTIVE
The purpose of this study was to evaluate the clinical and histopathologic features of pityriasis rubra pilaris(PRP) in Korea
METHODS
The clinical charts, photographies and skin biopsy slides of patients clinically diagnosed as PRP at the initial visit were reviewed. Finally 30 patients were diagnosed as PRP. They were classified into 5 groups according to the Griffiths classification. And then the evaluation of age at onset, sex distribution, clinical feature of the skin lesion, associated symptoms, clinical course and histopathologic features were conducted.
RESULTS
1) The male to female ratio was 1:1.14. The age of onset was varied from 1 to 65 years with two peaks in first and fifth decades. The average ages of onset in adult type and juvenile type were 40.1 and 5.1 years respectively. 2) According to the Griffiths classification, 14(47%) of the patients had type I, 4(13%) had type III, 7(23%) had type IV, and 3(10%) had type V. However, 2(7%)patients could not be classified under any of these five types due to atypical clinical feature or insufficient follow-up periods. 3) The common clinical features during the disease course were follicular hyperkeratosis(83%), knee and/or elbow involvement(83%), palm and/or sole hyperkeratosis(80%). Erythroderma was present in 5 patients(17%) during the disease course. 4) There were no specific symptoms in most cases, but 9 patients had ben suffered from mild itching. 5) 3 patients had a positive family history, and were thought to have inherited autosomal dominant trait. 6) The frequent histopathologic findings were alternating parakeratosis and orthokeratosis (100%), superficial perivascular infiltration(100%), broad rete ridge(97%), acanthosis(93%), hypergranulosis (87%), follicular plugging(73%).
CONCLUSION
We investigated the clinical and histopathological features of PRP in Korea. In our study, the clinical and histopathological features of PRP were not different from those observed in western patients.