Identification and speciation of malassezia in patients clinically suspected of having pityriasis versicolor

Beyond the Surface: Decoding Pityriasis Versicolor Through Clinical, Dermoscopic and Microbiological Exploration

Background

Pityriasis versicolor (PV) is an asymptomatic, superficial fungal infection caused by the Malassezia species and causes discolouration of the skin leading to altered pigmentation. It is usually a clinical diagnosis, but in doubtful cases wherein potassium hydroxide (KOH) mount is unavailable, alternative modalities like dermoscopy aid in the management.

Aims and Objectives

To evaluate the clinical and dermoscopic patterns in PV and correlate with the associated risk factors and study the fungal culture.

Materials and Methods

A cross-sectional observational study was conducted for 12 months. A total of 115 patients clinically diagnosed with PV showing positivity on KOH mount were recruited. Dermoscopy was done, following which the scales were scraped and cultured in the laboratory on Saborauds dextrose agar and modified Dixon media, and the results were analysed after 3 weeks.

Results

Among the 115 participants, on clinical evaluation, 79 patients had achromic and 36 patients had chromic lesions. The dermoscopic features were categorized into domains such as scaling, pigmentation and other features. Fine scaling was the most common feature observed in 88.7% of the patients. Pigmentary changes were noted in all the patients with non-uniform pigmentation being the most common. We have also observed and described newer dermoscopic findings such as barbed wire fence appearance of ridges and furrows, fluffy cotton ball appearance of hypopigmented perifollicular lesions and sprinkled pepper appearance of pigmented dispersion. Out of the 115 KOH mount positive cases, 51 (44.3%) showed growth on fungal culture with Malassezia furfur being the most common species to be isolated in 18 patients.

Conclusions

Dermoscopy is a new, popular non-invasive diagnostic modality, which shows specific features like fine scaling, pigment alteration, ridges and furrows with perifollicular involvement, and can be used to diagnose doubtful cases of PV as an adjunct or substitute to a KOH mount.

[Translated article] Wood's Light in Inflammatory and Autoimmune Dermatoses, Infections and Skin Cancer

Wood's light (WL) is a useful, economical and easy-to-learn diagnostic tool. Despite its advantages, the use of LW among dermatologists is limited. In porokeratosis, the "diamond necklace" sign has been described, corresponding to the white fluorescence of the hyperkeratotic scale. Subclinical morphea lesions are seen as well-defined dark macules. Among the pigmentary disorders, the bluish fluorescence of vitiligo, the increased contrast of epidermal melasma, and the follicular-centered red fluorescence of progressive macular hypomelanosis stand out. Regarding skin infections, erythrasma presents a coral red fluorescence; tinea versicolor, yellow-green fluorescence; Pseudomonas aeuriginosa, green fluorescence; and scabies, blue-white fluorescence in the acarine burrows. In skin cancer, LW has been used to delimit the surgical margins of both lentigo maligna and non-melanoma skin cancer, with variable results.

Wood's Light in Inflammatory And Autoimmune Dermatoses, Infections and Skin Cancer

Wood's light (WL) is a useful, economical and easy-to-learn diagnostic tool. Despite its advantages, the use of LW among dermatologists is limited. In porokeratosis, the "diamond necklace" sign has been described, corresponding to the white fluorescence of the hyperkeratotic scale. Subclinical morphea lesions are seen as well-defined dark macules. Among the pigmentary disorders, the bluish fluorescence of vitiligo, the increased contrast of epidermal melasma, and the follicular-centered red fluorescence of progressive macular hypomelanosis stand out. Regarding skin infections, erythrasma presents a coral red fluorescence; tinea versicolor, yellow-green fluorescence; Pseudomonas aeuriginosa, green fluorescence; and scabies, blue-white fluorescence in the acarine grooves. In skin cancer, LW has been used to delimit the surgical margins of both lentigo maligna and non-melanoma skin cancer, with variable results.

Pityriasis Versicolor-A Narrative Review on the Diagnosis and Management

This narrative review presents a comprehensive overview of the diagnosis and management of pityriasis versicolor (PV), a common superficial fungal infection caused by the yeast Malassezia. PV is characterised by scaly hypopigmented or hyperpigmented patches, primarily affecting the upper trunk, neck, and upper arms. Regarding commensal interactions, Malassezia utilises nutrient sources without affecting the human host. In cases of pathogenicity, Malassezia can directly harm the host via virulence factors or toxins, or indirectly by triggering damaging host responses. The diagnosis typically relies on recognising characteristic clinical features. Due to the wide variability in its clinical presentation, recognising the differential diagnosis is critical. In this paper, we discuss the clinical differentials, with their dermatoscopic presentation, but also describe a range of helpful diagnostic techniques (microscopy, conventional and ultraviolet-induced fluorescence dermatoscopy, and confocal microscopy). Topical therapies are the primary treatment for PV, encompassing non-specific antifungal agents like sulphur with salicylic acid, selenium sulphide 2.5%, and zinc pyrithione. Additionally, specific topical antifungal medications with either fungicidal or fungistatic properties may also be incorporated into the topical treatment regimen, such as imidazoles, allylamines, and ciclopirox olamine. Systemic therapies might occasionally be used. Patient education and the promotion of good personal hygiene are pivotal to reduce the risk of recurrence. In recurrent cases, particularly during warmer and more humid periods, prolonged prophylaxis with topical agents should be considered.

A Clinical and Epidemiological Study of Pityriasis Versicolor in Baghdad City

BACKGROUND: Pityriasis versicolor (PV) is a common and chronic superficial mycosis seen in all age groups and characterized by dyspigmented lesions caused by dimorphic lipophilic yeast. AIM: The aim of the study was to study the clinical aspects, prevalence, and demographic data of patients with PV in Baghdad City. MATERIALS AND METHODS: Total of 175 patients with PV attending the department of Dermatology at Al Imamein Al Kadhemein Medical City and Alkarama Teaching Hospital in Baghdad city from January 2019 to January 2020 were included in this study. Diagnosis was done clinically. Interviews with patients were done using a questionnaire designed by the researcher. RESULTS: From 175 patients with PV, there were 71 (40.6%) males and 104 (59.4%) females. The mean age was 23.97 ± 10.25 years. The majority of cases 71 (40.6%) were 21–30 years. Eighty-one (46.3%) patients were presented from April to June. Itching presented in 21.7% of patients. The majority of patients (48.6%) presented with hyperpigmented type. Neck was the most common site to be involved in 101 patients (57.7%). CONCLUSION: The most common age group affected was 21–30 years. Females were commonly affected. Peak incidence was observed in April–July months. Neck was the most common site affected. Hyperpigmented type is more commonly presented type.

Malassezia species: the need to establish Epidemiological Cutoff Values

Malassezia are common yeasts in human skin microbiome. Under certain conditions these yeasts may cause disease from skin disorders to systemic infections. In the absence of clinical breakpoints, epidemiological cutoff values (ECVs) are useful to differentiate isolates with acquired or mutational resistance. The aim of this work was to propose tentative ECVs of Malassezia furfur, M. sympodialis, M. globosa for fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), ketoconazole (KTZ) and amphotericin B (AMB). A total of 160 isolates (80 M. furfur, 50 M. sympodialis and 30 M. globosa) were tested. Minimal inhibitory concentrations (MICs) were determined by modified broth microdilution method (CLSI). ECVs were estimated by ECOFFinder software and two-fold dilutions beyond the mode. ITZ, KTZ and VCZ showed the lowest MICs. The highest MIC and widest ranges were for FCZ and AMB. For ITZ, KTZ and VCZ both ECVs were similar. For FCZ, AMB especially M. furfur, modal ECVs were lower than values obtained by statistical method. When MIC distribution is the only data available, ECV could provide information to help guide therapy decisions. In that drug/species combination in which different peaks in the MIC distribution were observed, difference between both ECV was greater. This is the first study that provides ECV data of 160 Malassezia yeasts. Although ECVs cannot be used as predictors of clinical response, identification of non wild-type isolates suggests that it may be less likely to respond to a given antifungal agent.

Revealing The Unseen: A Review of Wood's Lamp in Dermatology

In use for over a century, the Wood's lamp is a time-tested tool to aid in the diagnosis of certain superficial infections, pigmentary disorders, and metabolic diseases. To achieve its high utility, the Wood's lamp projects ultraviolet light onto the skin which in turn reflects a visible light that a trained eye can use to diagnose and monitor multiple dermatological ailments. Although new alternatives to Wood's lamp have been considered, it still remains a favored method of diagnosis because it is safe, cost-effective, and reliable. In this review, the authors explore the myriad applications of Wood's lamp in the field of dermatology.

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

Antagonistic Activity of Antimicrobial Metabolites Produced from Seaweed-Associated Bacillus amyloliquefaciens MTCC 10456 Against Malassezia spp

Members of the genus Malassezia are known to be opportunistic pathogens responsible for causing skin disorders such as seborrheic dermatitis or dandruff, pityriasis versicolor, folliculitis, atopic dermatitis, and psoriasis. Due to the side effects caused by prolonged use of current topical antifungal agents, development of an alternative treatment is necessary. Fermentative production of antimicrobial metabolites from Bacillus amyloliquefaciens MTCC 10456 was carried out, and their antagonistic activity against Malassezia furfur and Malassezia globosa was evaluated. The antifungal metabolites were isolated by acid precipitation, and bioassay-guided simultaneous separation of the antimicrobial compounds was done by reversed-phase high-performance liquid chromatography (RP-HPLC). The fraction which demonstrated antifungal activity consisted of bacilysin, homologues of bacillomycin D, and members of the macrolactin family. The presence of bacilysin was detected using specific inhibitor assays and homologues of bacillomycin D, and macrolactins were identified using liquid chromatography/high-resolution electrospray ionization-mass spectrometry (LC/HRESI-MS/MS) analysis. Synergism among the identified compounds was observed which enhanced the antagonistic activity against Malassezia spp. To our knowledge, this is the first study to report the co-production and separation of members of macrolactin antibiotics, lipopeptides such as bacillomycin D and dipeptide antibiotic bacilysin, by any Bacillus strain from marine environment. Activity of individual compounds against Malassezia has been reported which may facilitate their application in the field of dermatology and in cosmetic products.

FastFung: A novel medium for the culture and isolation of fastidious fungal species from clinical samples

We developed a novel culture medium, referred to FastFung medium as suitable for the culture of clinical fungi, including fastidious ones, for both research and diagnostic studies. It is based on Schædler agar supplemented with many essential components for the growth of fastidious fungi. It also contains selective antibacterial agents for the inhibition of contaminant bacteria growth. In this preliminary study, the FastFung medium was compared to the gold standard Sabouraud medium for 98 fungal and 20 bacterial strains. The fungal strain positive culture rate was 100% vs. 95% and the bacterial strain inhibition was 100% vs. 20%, for the FastFung and Sabouraud media, respectively. When compared to the Sabouraud medium on 120 clinical samples, the FastFung medium displayed both a higher fungal colonies count, and a lower culture contamination rate. Storage at 4 °C for 4 weeks did not alter the FastFung culture medium performances for the six isolates of Candida, Cryptococcus, and Penicillium tested. These encouraging results suggest future development of using the FastFung medium in clinical mycology and in mycobiome characterization. Further prospective evaluation aiming at assessing whether implementing the FastFung medium in the routine workflow simplifies and strengthen fungal isolation capacities in the clinical laboratory is warranted.

Dermoscopic pattern of pityriasis versicolor

Background: Pityriasis versicolor (PV) is essentially a clinical diagnosis characterized by hypopigmented or hyperpigmented patches on the skin. Dermoscopy is gaining popularity as a noninvasive procedure for the diagnosis of different pigmentary and inflammatory disorders. However, scarce evidence exists on the dermoscopic pattern of PV. Objective: To describe the dermoscopic features of hypopigmented and hyperpigmented lesions of PV. Methods: Dermoscopic images of PV lesions located on different body sites were retrospectively evaluated for the presence of predefined criteria. Results: A total of 178 lesions from 125 patients were included in the study among which 164 lesions were hypopigmented and 14 lesions were hyperpigmented. Nonuniform pigmentation was the most common dermoscopic feature seen in both hypopigmented lesions (n=152, 92.68%) and hyperpigmented lesions (n=14, 100%). Scales were seen in 142 hypopigmented lesions (86.56%) and 13 hyperpigmented lesions (92.86%). Patchy scaling was more common in hypopigmented lesions (n=95, 57.92%) while scaling in the furrows was more common in the dermoscopy of hyperpigmented lesions (n=5, 35.71%). Inconspicuous ridges and furrows and perilesional hyperpigmentation were other significant features seen in dermoscopy of the lesions. Conclusion: To our knowledge, this is the first study describing the dermoscopic features of PV in such a large number of patients. Description of these new features adds valuable information and may help to establish dermoscopy as an important auxiliary tool for the diagnosis of PV.

Phenotypic Identification and Molecular Characterization of Malassezia Spp. Isolated from Pityriasis Versicolor Patients with Special Emphasis to Risk Factors in Diyala Province, Iraq

AIM

The main objective is isolation and molecular characterisation of Malassezia spp. from pityriasis versicolor (PV) patients with special emphasis to risk factors in Diyala province, Iraq.

METHODS

Fifty patients (32 males and 18 females) presented with PV, the age ranged (15-45) years were included. Direct wet mount using KOH 10%, culture of skin scraping and PCR were used for confirmatory diagnosis.

RESULTS

Malassezia spp. was isolated from (54%) of skin scraping; M. furfur (32%); M. pachydermatis (8%) and M. globosa (14%). The age group (15-22) years were frequently exposed to Malassezia infection. A significant inverse correlation was reported between age and exposure to Malassezia spp. Infection. Males were frequently exposed to Malassezia infection, (40%). A significant correlation was reported between gender and exposure to Malassezia spp. Infection. Females were at risk of getting Malassezia infection (2.619) time than males. Patient resident in the urban area frequently exposed to Malassezia infection, (34%). Patients resident in the rural area appears to be at risk of getting Malassezia infection (1.093) time than those in an urban area. Patient with good economic status was frequently exposed to Malassezia infection, (36%). Patients with middle economic status appear to be at risk of getting Malassezia infection (0.42) time than those with good economic status. Patients with primary education were frequently exposed to Malassezia infection, (22%). A significant correlation was reported between education level and exposure to Malassezia spp. Infection. No significant correlation was reported between economic status; type of job; source of water; contact with dogs and birds and Malassezia spp. Infection.

CONCLUSION

M. furfur, M. pachydermatis and M. globosa represent the most common Malassezia spp. causing PV. Using of PCR is very critical to confirm the diagnosis of Malassezia spp. Malassezia infection inversely correlated with age and positively correlated with females gender and education. The residency in a rural area and middle economic status increase the possibility of infection. Infection was not affected by the source of water; job and contact with dogs and birds.

A Novel Contrast Stain for the Rapid Diagnosis of Pityriasis Versicolor: A Comparison of Chicago Sky Blue 6B Stain, Potassium Hydroxide Mount and Culture

BACKGROUND

The mycological study of pityriasis versicolor is usually done by potassium hydroxide (KOH) mount and culture. However, KOH mount lacks a color contrast and requires a trained eye to interpret, while culture is difficult to perform, time consuming and has low sensitivity. Chicago Sky Blue 6B (CSB) is a new contrast stain that highlights the fungal hyphae and spores, blue against a purplish background.

AIMS AND OBJECTIVES

This study was done to compare the utility of a novel contrast stain (CSB stain) with KOH mount and culture.

MATERIALS AND METHODS

Skin scrapings from the lesions of 100 clinically diagnosed cases of P. versicolor were subjected to (1) KOH mount and CSB stain for direct microscopic examination and (2) culture using Sabouraud's dextrose agar. The statistical analysis of CSB stain and culture was done using KOH mount as the reference method, as it is the most commonly performed and practical diagnostic test available for P. versicolor. An interrater reliability analysis using the Cohen's Kappa statistic was performed to determine consistency (agreement) among the different modalities.

OBSERVATIONS AND RESULTS

Direct microscopy with CSB stain, KOH mount and mycological culture showed positive results in 98 (98%), 92 (92%) and 56 (56%) patients, respectively. Using KOH mount as the reference method, CSB stain had a sensitivity of 100% which was significantly higher than culture (60.9%). Statistically significant fair agreement was found between CSB stain and KOH mount (94% with κ=0.38, P < 0.001). Negligible agreement was found between CSB stain and culture (66%, κ=0.199, P = 0.001) as well as between KOH mount and culture (64%, κ=0.051, P = 0.107).

CONCLUSION

CSB staining of skin scrapings is the most sensitive method for the diagnosis of pityriasis versicolor. Due to the distinct contrast provided by CSB, it is easy to perform, rapid and qualitatively superior to KOH mount.