A Clinical and Histopathological Study of Parapsoriasis

Hwang, Eul Sang; Kye, Young Chul; Kim, Soo Nam

Abstract

BACKGROUND
Parapsoriasis described a group of cutaneous disease that can be characterized by scaly patches or slightly elevated plaques that have a resemblance to psoriasis, hence the nomenclature. Up to now, a uniformly accepted definition of parapsoriasis remains lacking. OBJECTIVE: The purpose of this study was to evaluate the clinical and histopathological features of parapsoriasis in Korea. METHODS: The clinical charts, photographs and skin biopsy slides of patients who had been clinically diagnosed as parapsoriasis at the initial visit were reviewed. Then the evaluation of age at onset, sex distribution, disease duration, anatomical distribution, clinical features of the skin lesions, associated symptoms, family history, co-existing disease, and histopathologic features were conducted. Six cases from small plaque parapsoriasis group and four cases from large plaque parapsoriasis group were investigated for the presence of TCR gene rearrangement using a PCR technique. RESULTS: The male to female ratio was 1: 1.2. The average ages of onset in large plaque type and small plaque type were 44.7 and 32.9 years respectively. 1) According to the clinical classification, 7 (29%) of the patients had large plaque type and 17 (71%) had small plaque type. 2) Many lesions of large plaque parapsoriasis group exhibited varying degrees of epidermal atrophy, fine wrinkles and telangiectasia. 3) Large plaque parapsoriasis showed more histologic changes consisting of epidermal atrophy, exocytosis and atypical lymphocytes. 4) Monoclonal T-cell receptor gene rearrangement was not detected in all of 10 patients with large and small plaque parapsoriasis. CONCLUSION: In our study, some of our findings are in agreement with those already in the literature, whereas others, particularly the male to female ratio and constitutional symptoms, differ. Our results also indicate that there are many clinical and pathological differences between large plaque and small plaque parapsoriasis.