Clinical, Histopathological, and Immunohistochemical Differences between Men and Women with Psoriasis According to Disease Severity: Possible Role of Estrogen

Abstract

Background: Psoriasis is a chronic inflammatory skin disorder histopathologically characterized by epidermal hyperplasia, vascular proliferation, and inflammatory infiltrates. It runs a less severe course in women than in men. The role of estrogen in the pathogenesis of psoriasis remains unclear. Objective: We investigated the clinicohistopathological differences between men and women with psoriasis and examined whether serum estrogen levels and immunohistochemical findings correlate with gender and disease severity. Methods: We retrospectively reviewed the medical records of 500 patients with psoriasis. Among these patients, 60 who consented to participate in the study were classified into four groups as follows: 10 men showing psoriasis on ＜10% of their body surface area (BSA) with psoriasis area severity index (PASI)＜10: 20 men showing psoriasis on ≥10% of their BSA with PASI≥10: 10 women showing psoriasis on ＜10% of their BSA with PASI＜10: and 20 women showing psoriasis on ≥10% of their BSA with PASI ≥10. Serum estrogen levels were measured using radioimmunoassay. Immunohistochemical staining of skin biopsy tissues was performed using ERα, ERβ, and CCL5. Results: Men diagnosed with psoriasis showed higher BSA and PASI scores than women. Women aged ≥60 years showed higher BSA and PASI scores than women aged ＜60 years. There were no histological differences between the four groups. Serum estrogen levels were higher in the patients presenting with mild psoriasis, as well as in women. ERα, ERβ, and CCL5 showed a stronger staining tendency in patients with more severe psoriasis. Conclusion: Gender influences the severity of psoriasis, and estrogen plays an important role. This finding is explained by the fact that estrogen decreases inflammation in psoriasis possibly via its action on estrogen receptors in epidermal keratinocytes.