Distribution of Malassezia Species from Scales of Patient with Pityriasis Versicolor by Culture in Vietnam

Epidemiological characterization of pityriasis versicolor and distribution of Malassezia species among students in Hai Phong city, Vietnam

Background and Purpose:

Pityriasis versicolor (PV) is a common fungal skin infection caused by Malassezia species. Previous studies have shown that the prevalence of PV is influenced by geographic factors. The aim of the current study was to find the epidemiological characteristics of PV and distribution of Malassezia species in the secondary school students living in Hai Phong city, Vietnam.

Materials and Methods:

This study was conducted on 1357 students within the age range of 10 - 16 years selected from four secondary schools in Hai Phong city. The students were screened for PV skin lesions from August 2016 to December 2017. The isolates of Malassezia from PV patients were analyzed by performing direct microscopy and culturing on modified Dixon agar plates, containing gentamicin, at 32oC for 7 days. In the next stage, the fungal strains obtained from patients with positive fungal cultures were identified using the CHROMagarTM Malassezia medium, polymerase chain reaction-restriction fragment length polymorphism techniques, and D1/D2 rDNA genome sequencing.

Results:

Pityriasis versicolor was diagnosed in 305 (22.48%) students and confirmed by clinical appearance and direct examination. A total of 293 (96.07%) samples grew on modified Dixon agar. With regard to demographic characteristics, 50.49% of the PV cases were female, and 57.38% of cases resided in urban areas. Furthermore, 88.52% of the subjects had the illness duration of more than 6 months. Hypopigmented and erythematous skin lesions were also observed in the research participants, with hypopigmentation being the most frequent condition (97.05%). Most of the Malassezia fungal strains were isolated from the back (39.56%), face (23.99%), and chest (16.51%). Malassezia furfur and M. japonica accounted for PV in 96.25% and 3.75% of the cases, respectively. Furthermore, Malassezia furfur was distributed in both rural and urban areas, while M. japonica was found only in the urban areas.

Conclusion:

The findings of the present study were indicative of the high prevalence of Malassezia yeasts, mostly M. furfur, among the students in Hai Phong city, Vietnam

308-nm excimer laser: a hopeful and optional therapy for pityriasis versicolor

BACKGROUND

Pityriasis Versicolor (PV) is known as a superficial fungal infection. It is suggested that resistant strains to azoles may be developed and hence, the treatment would be difficult. This study aimed to evaluate the efficacy of excimer laser (308 nm) as an alternative therapy for PV.

MATERIALS AND METHODS

This is a prospective intra-patient left-to-right, randomized, placebo-controlled study conducted on 26 patients with bilateral lesions which are not responding to the PV standard treatment. Patients were randomly assigned to right or left-side therapy for a duration of 8 weeks with either excimer laser (308 nm three times weekly) or topical placebo. Clinical assessment and mycological evaluation were performed before the initiation of treatment and at the fourth and eighth week of therapy.

RESULTS

A decrease in the mean clinical score of cases was recorded from 7.1 at the baseline evaluation to 1.56 after 4 weeks and to 1.96 after 8 weeks of treatment. At week 4, there was a statistically significant reduction in the clinical scores compared with pretreatment scores and with the placebo group (p < .001).

CONCLUSION

308-nm excimer laser can be considered as a hopeful and optional therapy for PV.