Prevalence of tinea capitis in Southeastern Austria between 1985 and 2008: up-to-date picture of the current situation

Pediatric Tinea Capitis: A Retrospective Cohort Study from 2010 to 2021

Pediatric tinea capitis displays a wide range of prevalence, with significant variability among populations. We retrospectively extracted the medical records of 456 pediatric patients diagnosed with tinea capitis during the years 2010–2021, from the dermatology outpatient clinics in two tertiary medical centers. Three species were isolated in 90% of patients: T. tonsurans, M. canis, and T. violaceum. While T. tonsurans presented a six-fold increase in incidence during the years 2019–2021, M. canis maintained stable incidence rates. Furthermore, terbinafine was the most efficient antifungal agent against T. tonsurans, achieving complete clinical clearance in 95% of patients, as compared to fluconazole (68%) and griseofulvin (38%) (p < 0.001). The mycological cure was recorded in 61/90 (68%) of patients with available data, at an average of 10 weeks. For patients with M. canis, griseofulvin and fluconazole were equally efficient (73% and 66%, respectively) (p = 0.44). Kerion was described in 36% and 14% of patients with T. tonsurans and M. canis, respectively, (p < 0.001). In conclusion, since 2019, there has been a significant increase in the prevalence of T. tonsurans, establishing this pathogen as the most common cause for tinea capitis in our population. Our data suggest that terbinafine is effective and presents high cure rates for tinea capitis in the pediatric population.

Transcriptome sequencing revealed the inhibitory mechanism of ketoconazole on clinical Microsporum canis

Background

Microsporum canis is a zoonotic disease that can cause dermatophytosis in animals and humans.

Objectives

In clinical practice, ketoconazole (KTZ) and other imidazole drugs are commonly used to treat M. canis infection, but its molecular mechanism is not completely understood. The antifungal mechanism of KTZ needs to be studied in detail.

Methods

In this study, one strain of fungi was isolated from a canine suffering with clinical dermatosis and confirmed as M. canis by morphological observation and sequencing analysis. The clinically isolated M. canis was treated with KTZ and transcriptome sequencing was performed to identify differentially expressed genes in M. canis exposed to KTZ compared with those unexposed thereto.

Results

At half-inhibitory concentration (½MIC), compared with the control group, 453 genes were significantly up-regulated and 326 genes were significantly down-regulated (p < 0.05). Quantitative reverse transcription polymerase chain reaction analysis verified the transcriptome results of RNA sequencing. Gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the 3 pathways of RNA polymerase, steroid biosynthesis, and ribosome biogenesis in eukaryotes are closely related to the antifungal mechanism of KTZ.

Conclusions

The results indicated that KTZ may change cell membrane permeability, destroy the cell wall, and inhibit mitosis and transcriptional regulation through CYP51, SQL, ERG6, ATM, ABCB1, SC, KER33, RPA1, and RNP genes in the 3 pathways. This study provides a new theoretical basis for the effective control of M. canis infection and the effect of KTZ on fungi.

Clinical clues and trends in epidemiology and pathogens in paediatric tinea capitis: a retrospective cohort study

BACKGROUND

Tinea capitis is the most common dermatophyte infection in children. Pathogens differ between populations. During the past few decades pathogen shifts have been reported in many countries around the world. This study aimed to characterize the pathogens involved in tinea capitis in a large tertiary paediatric medical centre in Israel.

METHODS

The electronic medical records of the dermatology unit were searched for patients diagnosed with tinea capitis from 2010 to 2019, and demographic, clinical and mycological data were retrieved. A stepwise logistic regression was performed to determine the variables most significantly associated with positive cultures.

RESULTS

The prevalence of Trichophyton tonsurans isolates was found to be significantly increased during 2019. In the logistic regression analysis, alopecia was most significantly associated with a positive culture (OR = 8.72, 95% CI 4.29-17.7, P < 0.001) while positive culture was also associated with age (OR = 1.11 per year of age, 95% CI 1.02-1.22, P = 0.01) and Ethiopian ethnicity (OR = 3.67, 95% CI 1.42-9.45, P = 0.01). The presentation of alopecia was significantly related to having a positive culture. This symptom was more prevalent in boys than in girls, and the diagnosis of tinea capitis was delayed by an average of 2 months in girls.

CONCLUSION

The results of this study may herald a pathogen shift in Israel. Physicians should be aware that rates of alopecia are lower in girls and this can result in delayed diagnosis and the development of complications, including chronicity, scarring alopecia and kerion formation.

Aetiological changes of tinea capitis in the Hubei area in 60 years: Focus on adult tinea capitis

BACKGROUND

Tinea capitis is a common dermatophyte infection of the scalp primarily affecting children, with less frequent, though not rare, observation in adults.

OBJECTIVE

This study aimed to assess changes in the causative agents of adult tinea capitis over a 60-year period in the Hubei area.

METHODS

A retrospective, single-centre study was performed on 164 adults with tinea capitis between 1960 and 2020.

RESULTS

Out of 1113 cases of tinea capitis, 164 patients were adults, representing 14.7% of all patients. Adult tinea capitis was slightly more prevalent in males (91, 55.5%) than in females (73, 44.5%), but gender difference was not statistically significant between adults and children. Adult tinea capitis was most prevalent between the ages of 18 and 29 years, with a mean age of 22 years. Trichophyton schoenleinii was the most common dermatophyte in adult tinea capitis (78, 47.6%), followed by Trichophyton violaceum (58, 35.4%). Most adult tinea capitis cases before the 1980s were caused by T. schoenleinii, but T. violaceum has become the leading pathogen for recent adult tinea capitis cases.

CONCLUSION

Tinea capitis is not a disease exclusive to children. On the contrary, an upward trend of tinea capitis in adults has been observed in recent years. T. violaceum has become the dominant causative agent of adult tinea capitis in the Hubei area, replacing T. schoenleinii. These results provide a better understanding of the treatment and prevention of tinea capitis in adults.

S1 guidelines: Tinea capitis

Tinea capitis describes a dermatophyte infection of scalp and hair that predominately occurs in children. The diagnostic workup includes microscopic examination, culture and/or molecular tests. Treatment is guided by the specific organism involved and should consist of systemic agents as well as adjuvant topical treatment. The aim of the present update of the interdisciplinary German S1 guidelines is to provide dermatologists, pediatricians and general practitioners with a decision tool for selecting and implementing appropriate diagnostic and therapeutic measures in patients with tinea capitis. The guidelines were developed based on current international guidelines, in particular the 2010 European Society for Pediatric Dermatology guidelines and the 2014 British Association of Dermatologists guidelines, as well as on a review of the literature conducted by the guideline committee. This multidisciplinary committee consists of representatives from the German Society of Dermatology (DDG), the German-Speaking Mycological Society (DMykG), the German Society for Hygiene and Microbiology (DGHM), the German Society of Pediatric and Adolescent Medicine (DGKJ) and the German Society for Pediatric Infectious Diseases (DGPI). The Division of Evidence-based Medicine (dEBM) provided methodological assistance. The guidelines were approved by the participating medical societies following a comprehensive internal and external review.

FSH1 regulates the phenotype and pathogenicity of the pathogenic dermatophyte Microsporum canis

Microsporum canis (M. canis) is a common pathogen that causes tinea capitis and is present worldwide. The incidence of M. canis infection, particularly tinea capitis, has been increasing in China. In our previous studies, family of serine hydrolases 1 (FSH1) was identified as a potential virulence factor in tinea capitis infection caused by M. canis. To determine the function of this gene in M. canis, FSH1 was knocked down using double-stranded RNA interference mediated by Agrobacterium tumefaciens. Reverse transcription-quantitative PCR analysis was used to confirm gene knockdown. Loss of FSH1 expression by RNAi resulted in a minor phenotype alteration, but M. canis pathogenicity in guinea pig cutaneous infection was decreased compared with the wild-type strain. To the best of our knowledge, the present study is the first to demonstrate that FSH1 is associated with macroconidia septa formation and is an important contributor to M. canis virulence. These findings may advance the understanding of the function of the FSH1 gene and provide a foundation for future studies on macroconidia septa formation and pathogenicity of M. canis.

Tinea Capitis: Correlation of Clinical Aspects, Findings on Direct Mycological Examination, and Agents Isolated from Fungal Culture

Background:

Tinea capitis (TC) is a dermatophytosis of the scalp caused by the Trichophyton and Microsporum genera. The condition can be classified according to clinical symptoms or based on mycological presentations observed on direct examination. Treatment is best determined after isolation of the causative agent, with griseofulvin indicated for Microsporum and terbinafine for Trichophyton.

Materials and Methods:

This was a prospective study correlating clinical and mycological classifications with agents isolated from culture of patients seen at a tertiary hospital in São Paulo (Brazil) between May 15, 2017, and January 11, 2019.

Results:

A total of 23 patients were treated, comprising 19 (83%) with alopecic clinical aspect (14 [60%] trichophytic and five [23%] microsporic) and 4 (17%) with kerion celsi presentation. According to the parasite invasion at the hair shaft, 9 (40%) were endothrix and 14 (60%) were ectothrix cases. Trichophyton tonsurans was isolated from culture in 14 (60%) patients and Microsporum canis in 5 (40%) patients. A statistically significant association was found for mycological classification and agent isolated from culture (P = 0.003) with associations of the endothrix form with T. tonsurans and of ectothrix with M. canis.

Conclusions:

The mycological classification appears to be a valid method for suggesting the etiological agent of TC.

Epidemiological profile of tinea capitis in São Paulo City

Tinea capitis is the most common fungal infection in children. The identification of the etiologic agent helps clinicians make their therapeutic choice. Studies conducted in different countries show a changing pattern of the main etiological agents according to their regions. We performed a retrospective study in the tertiary public service in São Paulo, analyzing the isolated etiological agents in patients with tinea capitis from March 2013 to May 2015. Microsporum canis was the main agent (56.6%), followed by Trichophyton tonsurans (36.6%). Despite recent migratory movements in the city, we observed no change in the causative agent of tinea capitis.

Clinical, epidemiological, and therapeutic profile of dermatophytosis

BACKGROUND

The cutaneous mycoses, mainly caused by dermatophyte fungi, are among the most common fungal infections worldwide. It is estimated that 10% to 15% of the population will be infected by a dermatophyte at some point in their lives, thus making this a group of diseases with great public health importance.

OBJECTIVE

To analyze the clinical, epidemiological, and therapeutic profile of dermatophytosis in patients enrolled at the Dermatology service of Universidade do Estado do Pará, Brazil, from July 2010 to September 2012.

METHOD

A total of 145 medical records of patients diagnosed with dermatophytosis were surveyed. Data were collected and subsequently recorded according to a protocol developed by the researchers. This protocol consisted of information regarding epidemiological and clinical aspects of the disease and the therapy employed.

RESULTS

The main clinical form of dermatophyte infection was onychomycosis, followed by tinea corporis, tinea pedis, and tinea capitis. Furthermore, the female population and the age group of 51 to 60 years were the most affected. Regarding therapy, there was a preference for treatments that combine topical and systemic drugs, and the most widely used drugs were fluconazole (systemic) and ciclopirox olamine (topical).

CONCLUSION

This study showed the importance of recurrent analysis of the epidemiological profile of dermatophytosis to enable correct therapeutic and preventive management of these conditions, which have significant clinical consequences, with chronic, difficult-totreat lesions that can decrease patient quality of life and cause disfigurement.

Pathogenic fungus Microsporum canis activates the NLRP3 inflammasome

Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into its mature form. To determine whether the inflammasome is involved in the host defense against M. canis infection, we challenged human monocytic THP-1 cells and mouse dendritic cells with a clinical strain of M. canis isolated from patients with tinea capitis. We found that M. canis infection triggered rapid secretion of IL-1β from both THP-1 cells and mouse dendritic cells. Moreover, by using gene-specific shRNA and competitive inhibitors, we determined that M. canis-induced IL-1β secretion was dependent on NLRP3. The pathways proposed for NLRP3 inflammasome activation, namely, cathepsin B activity, K(+) efflux, and reactive oxygen species production, were all required for the inflammasome activation triggered by M. canis. Meanwhile, Syk, Dectin-1, and Card9 were found to be involved in M. canis-induced IL-1β secretion via regulation of pro-IL-1β transcription. More importantly, our data revealed that M. canis-induced production of IL-1β was dependent on the NLRP3 inflammasome in vivo. Together, this study unveils that the NLRP3 inflammasome exerts a critical role in host innate immune responses against M. canis infection, and our data suggest that diseases that result from M. canis infection might be controlled by regulating the activation of inflammasomes.