The genetic epidemiology of tinea versicolor in China

Oral Malassezia infection co-occurring with tinea versicolor: metagenomic sequencing of the saliva

Malassezia is a lipid-dependent cutaneous symbiotic fungal genus associated with tinea versicolor. Here, we first present a rare case of a young tinea versicolor patient with oral manifestations presenting as white strips, patches, and pigmentation. The patient had a family history of tinea versicolor and a habit of frequent intake of cream. Histopathologic features and periodic acid-schiff staining of oral lesion indicated oral infection with round budding yeasts with short hyphae. Saliva metagenomic sequencing identified Malassezia and demonstrated the upregulated amount, diversity and activity of inflammatory bacteria. The clinical manifestations of oral Malassezia infection and changes in bacterial communities shed light on the pathogenic role of Malassezia in oral mucosa. In conclusion, we report the first oral Malassezia infection, which broadens the pathogenic cognitive scope of Malassezia and highlights the value of molecular techniques in the diagnostic process.

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.

Prevalence of skin infections, infestations, and papular urticaria among adolescents in secondary schools in Calabar, Nigeria

Background

Acne is an inflammatory disorder of the pilosebaceous gland, and the most common dermatosis in adolescents globally. Infectious dermatoses are common in the tropics, but due to the paucity of epidemiologic surveys, not much is known about the prevalence and common types found in different sub-populations including adolescents. It is however presumed that the prevalence will be high and the pattern diverse. We therefore conducted a school-based survey to ascertain the prevalence and pattern of infectious dermatoses, infestations, and papular urticaria (insect bite reactions) in teenage adolescents in Calabar, Nigeria.

Methods

A cross sectional observational survey of adolescents aged 13–19 years attending randomly selected secondary schools in Calabar, Nigeria. It involved the use of questionnaires and subsequent whole body examination.

Results

A total of 1447 senior secondary school students were examined. Infectious dermatoses, infestations, and papular urticaria (IDIP) were observed in 505 (34.9%) persons, among whom were 269 (53.3%) males, and 236 (46.7%) females (X²=34.87, p=<0.001). Fungal dermatoses constituted more than 90% of the diseases, the bulk of which was contributed by pityriasis versicolor [430 (79.6%)]. The six most common dermatoses in descending order of frequencies were Pityriasis versicolor, tinea, papular urticaria, candidiasis, furuncles, and viral warts.

Conclusion

A high prevalence of cutaneous infections exists among teenage adolescents in Calabar, Nigeria. Males have a higher predisposition to fungal dermatoses. Control of the predominant cause of cutaneous infections — pityriasis versicolor, will significantly affect the prevalence of infectious dermatoses, and invariably, the burden of skin disorders in adolescents in Calabar, Nigeria.

Funding

Self sponsored

An analysis of the Malassezia species distribution in the skin of patients with pityriasis versicolor in Chengdu, China

Pityriasis versicolor (PV) is a common clinical problem associated with Malassezia species (Malassezia spp.). Controversies remain regarding the specific species involved in the development of PV. This study analyzed the difference in Malassezia spp. distribution in lesional and nonlesional skin in Chinese PV patients. A paired design was applied. Lesional and nonlesional scales from 24 cases were collected; real-time fluorescence quantitative PCR was used to detect 10 different Malassezia spp. In lesional skin, the highest detection rates were for M. globosa (95.8%), M. restricta (91.7%), and M. sympodialis (50.0%). In nonlesional skin, the highest detection rates were for M. globosa (87.5%), M. restricta (79.2%), and M. dermatis (33.3%). A significant difference in the detection rate was only found for M. sympodialis (50.8% versus 20.8%, P = 0.04). Compared with nonlesional skin, the amount of M. globosa, M. restricta, and M. sympodialis in lesional skin was significantly higher (3.8 ± 1.3,  2.5 ± 1.1, and 3.2 ± 1.6 times higher, resp.). The results of this study do not indicate that M. globosa and M. restricta are directly correlated with PV development; however, M. sympodialis is more likely related to PV development in Chinese individuals.

Dermatologic conditions in teenage adolescents in Nigeria

Background

Skin disorders are common in adolescents, and the impact on quality of life can be enormous, particularly when viewed against the backdrop of the visibility of skin diseases and the psychologically vulnerable period of adolescence. However, few studies have documented the magnitude of skin disorders in this subset of individuals. We therefore estimated the point prevalence and pattern of dermatologic conditions in adolescents attending various secondary schools in Calabar, Southern Nigeria.

Methods

Using a structured questionnaire, relevant sociodemographic information was obtained from 1,447 teenage adolescents from eight secondary schools. Thereafter, a whole body examination was conducted to determine the presence and types of skin disorders seen.

Results

Skin diseases were seen in 929 students. The point prevalence was higher in males (72.1%) than in females (58.3%). Private schools had a higher prevalence than public schools. The six most common dermatoses were acne vulgaris, pityriasis versicolor, nevi, tinea, miliaria, and keloid/hypertrophic scars, and accounted for over 80% of the dermatoses seen.

Conclusion

The point prevalence of dermatoses in senior secondary school adolescents was 64.2%. Although a large number of skin disorders were observed, only a handful accounted for a significant proportion of the diseases seen. This increases the ease of training community health workers in the recognition and treatment of common skin diseases. Age, race, and climatic factors are important determinants of skin diseases in adolescents in Nigeria.

The Malassezia genus in skin and systemic diseases

In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.