Analysis of fungal colonization in skin surfaces of patients with atopic dermatitis / 中华皮肤科杂志

ABSTRACT

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.