特应性皮炎患者皮肤表面真菌定植分析

Analysis of fungal colonization in skin surfaces of patients with atopic dermatitis

目的：观察念珠菌、红酵母、青霉、曲霉在特应性皮炎患者皮肤表面定植情况，分析这4种常见致敏真菌与特应性皮炎症状严重程度的相关性。方法特应性皮炎患者50例，健康对照组20例。刮取特应性皮炎患者皮损部位及非皮损部位的鳞屑（以四肢屈侧为主）、健康对照组肘关节屈侧皮屑行真菌镜检，无1例发现菌丝或假菌丝；将皮屑标本接种于沙氏葡萄糖培养基，置25℃恒温箱内培养，发现真菌及酵母样可疑菌落，转种沙氏葡萄糖培养基斜面，获得纯培养后，根据菌落形态特征及颜色、菌落生长的快慢、镜下孢子及菌丝的特征进行菌种鉴定。结果特应性皮炎组50例，皮损表面检出念珠菌29例（58%）、红酵母17例（34%）；健康对照组20例，检出念珠菌5例（25%）、红酵母2例（10%），特应性皮炎组念珠菌、红酵母检出率明显高于健康对照组（χ2值分别为6.23、4.10，均P〈0.05）。重度患者25例，检出念珠菌19例（76%）、红酵母12例（48%）；中度患者25例，检出念珠菌10例（40%）、红酵母5例（20%），重度患者皮损表面念珠菌、红酵母检出率明显高于中度患者（χ2值分别为6.65、4.37，均P〈0.05）。患者组与对照组青霉、曲霉检出率差异无统计学意义。结论特应性皮炎患者皮肤表面念珠菌、红酵母定植明显高于健康对照组，且重度患者定植率高于中度患者，表明真菌定植的种类与皮肤的健康状况相关，与特应性皮炎患者症状的严重程度相关。

Objective To analyze the colonization of Candida, Rhodotorula, Penicillium and Aspergillus in skin surfaces of patients with atopic dermatitis, and to assess the relationship between the four common fungal allergens and severity of atopic dermatitis. Methods Fifty patients with atopic dermatitis and 20 healthy controls were enrolled. Scales were scraped from lesional and non？lesional skin of flexural extremities of the patients, as well as from normal skin of the flexural elbow of healthy controls, then were subjected to microscopic examination and culture. Scale specimens were inoculated onto Sabouraud dextrose agar medium and cultured at 25 ℃ in a constant temperature incubator. Subsequently, suspected fungal or yeast？like colonies were collected for pure culture. Finally, fungal strains were identified according to colony morphology, color, growth speed, as well as microscopic features of spores and hyphae. Results No hyphae or pseudohyphae were found in any case by microscopic examination. Candida albicans and Rhodotorula were detected in 29（58%）and 17（34%）out of the 50 patients, respectively, and in 5（25%）and 2 （10%） out of the 20 healthy controls, respectively. The detection rates of Candida albicans and Rhodotorula were significantly higher in the patients than in the controls（χ2=6.23, 4.10, respectively, both P〈0.05）. Of 25 patients with severe lesions, 19（76%）and 12（48%）were colonized by Candida albicans and Rhodotorula respectively;among 25 patients with moderate lesions, 10 （40%） and 5 （20%） were colonized by Candida albicans and Rhodotorula respectively. An increase was observed in the detection rates of Candida albicans and Rhodotorula in the patients with severe lesions compared with those with moderate lesions（χ2=6.65, 4.37, respectively, both P〈0.05）. There was no significant difference in the detection rate of Penicillium or Aspergillus between the patients and health controls. Conclusion The colonization rates of Candida albicans and Rhodotorula on skin surfaces were higher in patients with atopic dermatitis than in healthy controls, and higher in patients with severe lesions than in patients with moderate lesions, indicating that the types of colonizing fungi are associated with the health status of skin and severity of symptoms in patients with atopic dermatitis.