Braun-Falco O, Heilgemeir G P, Lincke-Plewig H
Hautarzt. 1979 Sep;30(9):478-83.
The clinical differential diagnosis between seborrheic dermatitis and psoriasis vulgaris of the scalp can be difficult. We, therefore, tried to elaborate histopathological criteria for a differentiation of the two dermatoses. Forty excisional biopsies were analysed without knowing the clinical diagnosis. The histopathological substrate within the epidermis is characterized in psoriasis by dermatitis-like and in seborrheic dermatitis by psoriasis-like alterations. Therefore, in some cases a definite histopathological diagnosis could not be made. Strong criteria favouring psoriasis are: moderate condensed hyperkeratosis with alternating parakeratosis, PAS-reactive serum inclusions and Munro abscesses within the horny layer, spongiform pustles and neutrophilic leukocytes within the epidermis. Strong criteria for seborrheic dermatitis are: irregular acanthosis with relatively thin condensed orthoor parakeratotic horny layer, spongiosis and spongiotic vesicles, exocytosis of lymphocytes and the lack of any hard criterias for psoriasis. The results may suggest that seborrheic dermatitis of the scalp may transform into psoriasis in patients with a genetical disposition ("psoriatic diathesis", "latent psoriasis") via a Köbner reaction. The existence of the seborrheic dermatitis (Morbus Unna) is not doubted by these investigations.
头皮脂溢性皮炎和寻常型银屑病的临床鉴别诊断可能存在困难。因此，我们试图阐述两种皮肤病鉴别的组织病理学标准。在不知临床诊断的情况下，对40例切除活检标本进行了分析。银屑病表皮内的组织病理学特征为类皮炎样改变，脂溢性皮炎则为类银屑病样改变。因此，在某些病例中无法做出明确的组织病理学诊断。支持银屑病的有力标准包括：中度致密性角化过度伴交替性角化不全、角质层内PAS反应性血清包涵体和Munro微脓肿、表皮内海绵状脓疱和中性粒细胞。脂溢性皮炎的有力标准包括：不规则棘层肥厚，伴有相对较薄的致密性正角化或角化不全角质层、海绵形成和海绵状水疱、淋巴细胞外渗，且缺乏任何支持银屑病的明确标准。结果可能提示，头皮脂溢性皮炎在具有遗传易感性（“银屑病素质”、“潜在银屑病”）的患者中，可能通过同形反应转变为银屑病。这些研究并未质疑脂溢性皮炎（Unna病）的存在。
