[Application of methylene blue staining in detection of Malassezia].

OBJECTIVE

To assess the value of methylene blue and parker ink staining in the detection of Malassezia.

METHODS

Detecting Malassezia in three dermatoses samples (pityriasis versicolor, Malassezia folliculitis and dandruff) stained by methylene blue (3 g/L) or parker ink. Comparing the effectiveness and the positive rates of Malassezia detection between the two staining methods. Staining Malassezia and Candida and comparing the specificity of the two staining methods in staining Malassezia.

RESULTS

Dark blue hyphae and spores were observed in smears stained by methylene blue, and light blue hyphae and spores were observed in smears stained by parker ink. Hyphae and spores were easy to identify on the background. The positive rates of methylene blue and parker ink for detecting Malassezia in the three dermatoses were 96% and 94% respectively. There was no significant difference between the two dye liquors in the positive rate for deterting Malassezia. Both Malassezia and Candida could be stained by methylene blue; nevertheless, only Malassezia could be stained by parker ink.

CONCLUSION

Both methylene blue and parker ink staining can be used to detect Malassezia, but parker ink has higher specificity in Malassezia staining.