Department of Dermatology, The First Affiliated Hospital of Army Medical University, Chongqing, China.
Department of Dermatology, Rheumatology and Immunology, The Second Affiliated Hospital of Army Medical University, Chongqing, China.
Skin Res Technol. 2023 Jan;29(1):e13258. doi: 10.1111/srt.13258.
Pigmented prurigo (PP) is a chronic and recurrent inflammatory skin disease. PP is not common clinically, but it is easily misdiagnosed because of its diversified clinical manifestations in different stages.
We retrospectively analyzed the clinical, histopathological, dermoscopy, and reflectance confocal microscopy (RCM) features of 20 patients diagnosed as PP.
The female predominance ratio was revealed with male to female of 1:4. Seven female patients were on a diet (without staple food) and one patient had a history of diabetes. Eight cases were suffered in spring, six cases in winter, three cases in summer, and three cases in autumn. Multiple sites were involved in 13 cases. Four patients had urticarial papules and plaques. Nineteen patients had erythematous papules with reticular distribution, of which 14 cases accompanied reticulate hyperpigmentation, four cases with papulovesicle, and two cases accompanied with pustules. One patient only showed reticulate hyperpigmentation. In the early lesions, dermatoscopy showed pink oval lesions, punctate or linear vessels, and pale yellow rings around the skin lesions. RCM is characterized by spongiosis, spongy vesicle, neutrophils scattered in the epidermis, which was consistent with epidermis spongiosis, neutrophils infiltrating into the upper epidermis and necrotic keratinocytes in histopathology. In the fully developed lesions, dermatoscopy showed pink lesions with brown pigment granules in the center and linear vessels in the edge. RCM showed that demarcation of epidermis and dermis is not clear, and inflammatory cells can be seen in the upper dermis and histopathologically lesions assumed a patchy lichenoid pattern, and the inflammatory cells infiltrating the dermis were dominated by lymphocytes. In the late lesions, dermatoscopy showed grainy grayish-brown or yellowish-brown pigmentation surrounding the hair follicle merging with each other. RCM showed that pigment granules were increased on the ring of basal cells, inflammatory cells were sparsely infiltrated in the dermal papilla and superficial layer, and epidermis slightly hyperplastic, with melanophages and a few lymphocytes infiltrating the superficial dermis in histopathology.
PP is easily misdiagnosed and not always occurs in those on a restrictive diet. A combination of dermatoscopy and RCM is helpful for its diagnosis of PP.
色素性痒疹（PP）是一种慢性复发性炎症性皮肤病。临床上并不常见，但由于其在不同阶段的临床表现多样化，容易误诊。
我们回顾性分析了 20 例诊断为 PP 的患者的临床、组织病理学、皮肤镜和反射共聚焦显微镜（RCM）特征。
女性患者比例明显高于男性，男女比例为 1:4。7 名女性患者进行饮食限制（无主食），1 名患者有糖尿病病史。8 例发生于春季，6 例发生于冬季，3 例发生于夏季，3 例发生于秋季。13 例患者为多部位受累。4 例患者有荨麻疹样丘疹和斑块。19 例患者有红斑性丘疹，呈网状分布，其中 14 例伴有网状色素沉着，4 例有丘疹水疱，2 例伴有脓疱。1 例患者仅表现为网状色素沉着。在早期病变中，皮肤镜显示粉红色椭圆形皮损，点状或线状血管，皮损周围有淡黄色环。RCM 表现为海绵形成，海绵状水疱，散在表皮的中性粒细胞，与组织病理学上的表皮海绵形成、中性粒细胞浸润至上表皮和坏死角质形成细胞一致。在完全发展的病变中，皮肤镜显示粉红色皮损，中心有棕色色素颗粒，边缘有线性血管。RCM 显示表皮和真皮分界不清，真皮浅层可见炎症细胞，组织病理学上病变呈斑片状苔藓样模式，真皮浸润的炎症细胞以淋巴细胞为主。在晚期病变中，皮肤镜显示围绕毛囊的颗粒状灰棕色或黄褐色色素沉着相互融合。RCM 显示基底层环的色素颗粒增多，真皮乳头和浅层稀疏浸润炎症细胞，表皮轻度增生，组织病理学上浅层真皮有黑素细胞和少量淋巴细胞浸润。
PP 容易误诊，并非总是发生在饮食限制的患者中。皮肤镜和 RCM 的结合有助于其诊断。
