Department of Dermatology, Loma Linda University Health, Loma Linda, California, USA.
Department of Pathology and Dermatology, University of California San Francisco, San Francisco, California, USA.
J Cutan Pathol. 2024 Aug;51(8):618-623. doi: 10.1111/cup.14633. Epub 2024 Apr 30.
Psoriasis is an inflammatory skin disease driven by upregulation of cytokines in the Th17 pathway, including interleukin-36 (IL-36). Previous studies have highlighted the utility of IL-36 immunostaining for psoriasis compared to spongiotic dermatitis and other psoriasiform dermatoses; however, no study has examined the role of IL-36 staining in distinguishing psoriasis from pityriasis rosea (PR) and pityriasis lichenoides (PL), known histologic mimickers of psoriasis.
We compared the immunostaining pattern of IL-36 for 21 PR cases, 22 PL cases, and 10 psoriasis cases. We graded the immunostaining as 0, negative; 1, focal weak; 2, diffuse weak; 3, focal, strong; or 4, diffuse strong. We further categorized stains as negative (0-2 score) or positive (3-4 score) and utilized Fisher's exact test to compare the immunostaining pattern of these entities.
All psoriasis specimens were positive for IL-36, whereas all PR specimens were negative (p = 0.00000002). Twenty PL specimens were negative (p = 0.000001). Nine of 10 pityriasis lichenoides et varioliformis acuta cases were negative (p = 0.00012), and 11 of 12 cases of pityriasis lichenoides chronica were negative (p = 0.00003).
Our findings highlight the potential role of IL-36 immunostaining in distinguishing psoriasis from other psoriasiform dermatoses, including PR and PL.
银屑病是一种炎症性皮肤病，其特征是 Th17 通路中的细胞因子上调，包括白细胞介素-36（IL-36）。先前的研究强调了 IL-36 免疫染色在银屑病与海绵状皮炎和其他银屑病样皮肤病中的应用价值；然而，尚无研究探讨 IL-36 染色在鉴别银屑病与玫瑰糠疹（PR）和苔藓样糠疹（PL）中的作用，这两种疾病均为银屑病的组织学模拟疾病。
我们比较了 21 例 PR 病例、22 例 PL 病例和 10 例银屑病病例的 IL-36 免疫染色模式。我们将免疫染色评为 0 分（阴性）、1 分（局灶性弱）、2 分（弥漫性弱）、3 分（局灶性强）或 4 分（弥漫性强）。我们进一步将染色分为阴性（0-2 分）或阳性（3-4 分），并利用 Fisher 确切检验比较这些实体的免疫染色模式。
所有银屑病标本均为 IL-36 阳性，而所有 PR 标本均为阴性（p = 0.00000002）。20 例 PL 标本为阴性（p = 0.000001）。10 例急性痘疮样苔藓样糠疹中有 9 例为阴性（p = 0.00012），12 例慢性苔藓样糠疹中有 11 例为阴性（p = 0.00003）。
我们的研究结果强调了 IL-36 免疫染色在鉴别银屑病与其他银屑病样皮肤病（包括 PR 和 PL）中的潜在作用。
