Department of Medical Mycology and Parasitology, School of Medicine, Sari, Iran.
Eur Rev Med Pharmacol Sci. 2010 Jan;14(1):63-8.
In recent years, the genus Malassezia has come to be considered important in the etiology of seborrhoeic dermatitis (SED). The aim of present study was identification of Malassezia species on the lesions of Iranian SED patients.
100 patients with SED were enrolled in the study. The patients were evaluated both clinically for the severity of SED and microscopically for the presence of the yeast Malassezia. Diagnosis of Malassezia was made after the yeast Malassezia was microscopically observed on skin scales stained with methylene blue. All samples were also cultivated on Leeming and Notman and Sabouraud's dextrose agar culture media. The agar plates were incubated at 32 degrees C for 2 weeks and evaluated for the existence of growth every day for one week. Identification of isolated yeast was based on morphological and physiological characteristics.
From 100 patients with SED, 60% were female. The age range was 12-65 years with median 27.3 years. The highest prevalence of SED was seen in 20-29 years age group. 59% and 41% of patients had local and generalized lesions, respectively. 58% of patients showed lesion on scalp. Microscopic examination of skin scales was positive in 100% of SED lesions. 96% of patients showed more than 1-3 yeasts in each microscopic field whereas only 4% patients showed 1-3 yeasts in whole slide. Totally, 77% of the specimens yielded Malassezia in culture. Malassezia globosa was the most commonly isolated Malassezia species (55.8%). Malassezia globosa had also most frequencies on scalp and face lesions. Malassezia furfur had most frequency on trunk lesions.
The results of our study showed high recovery rate of Malassezia species on lesions of patients with SED. So it might be playing a causative role in the etiology of this disease.
近年来，马拉色菌属被认为与脂溢性皮炎（SED）的病因有关。本研究的目的是鉴定伊朗 SED 患者皮损中的马拉色菌属菌种。
纳入 100 例 SED 患者。对患者进行临床评估以确定 SED 的严重程度，并用亚甲蓝染色的皮肤鳞屑进行显微镜检查以观察酵母样真菌的存在。在皮肤鳞屑上观察到酵母样真菌后，即可诊断为马拉色菌病。所有标本均接种于 Leeming 和 Notman 和 Sabouraud 葡萄糖琼脂培养基上。琼脂平板在 32°C 下孵育 2 周，并在第 1 周每天评估是否有生长。分离出的酵母的鉴定基于形态学和生理学特征。
100 例 SED 患者中，60%为女性，年龄范围为 12-65 岁，中位数为 27.3 岁。SED 发病最高的年龄组为 20-29 岁。59%和 41%的患者分别有局限性和全身性皮损。58%的患者头皮有皮损。100%的 SED 皮损皮肤鳞屑镜检阳性。96%的患者在每个显微镜视野中显示超过 1-3 个酵母，而只有 4%的患者在整个载玻片上显示 1-3 个酵母。总的来说，77%的标本在培养中可培养出马拉色菌。球形马拉色菌是最常分离到的马拉色菌种（55.8%）。球形马拉色菌在头皮和面部皮损中也最常见。糠秕马拉色菌在躯干皮损中最常见。
我们的研究结果表明，SED 患者皮损中马拉色菌属的回收率较高，因此可能在该病的病因中起因果作用。
