Increased incidence ofTrichophyton tonsuranstinea capitis in Ontario, Canada between 1985 and 1996

Changing Epidemiology of Tinea Capitis in Athens, Greece: The Impact of Immigration and Review of Literature

Mass population movements have altered the epidemiology of tinea capitis (TC) in countries receiving refugees. Periodic monitoring of the local pathogen profiles may serve as a basis for both the selection of appropriate empirical antifungal therapy and the implementation of preventive actions. Therefore, we investigated the impact of an unprecedented immigration wave occurring in Greece since 2015 on the epidemiological trends of TC. All microbiologically confirmed TC cases diagnosed during the period 2012-2019 in a referral academic hospital for dermatological disorders in Athens, Greece, were retrospectively reviewed. A total of 583 patients were recorded, where 348 (60%) were male, 547 (94%) were children and 160 (27%) were immigrants from Balkan, Middle Eastern, Asian as well as African countries. The overall annual incidence of TC was 0.49, with a significant increase over the years (p = 0.007). M. canis was the predominant causative agent (74%), followed by T. violaceum (12%), T. tonsurans (7%) and other rare dermatophyte species (7%). M. canis prevalence decreased from 2014 to 2019 (84% to 67%, p = 0.021) in parallel with a three-fold increase in T. violaceum plus T. tonsurans rates (10% to 32%, p = 0.002). An increasing incidence of TC with a shift towards anthropophilic Trichophyton spp. in Greece could be linked to the immigration flows from different socioeconomic backgrounds.

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.

Genotype Analysis of the Variable Internal Repeat Region in the rRNA Gene ofTrichophyton tonsuransIsolated from Japanese Judo Practitioners

Tinea capitis due to Trichophyton tonsurans is currently epidemic among Japanese Judo practitioners. T. tonsurans has seven genotypes in a variable internal repeat (VIR) region of the rRNA gene. All 101 isolates obtained from Japanese Judo practitioners had the identical genotype. This suggests that a specific genotype strain occurs throughout Japan.

Inflammatory Tinea capitis: a 12-year study and a review of the literature

Inflammatory Tinea capitis (TC) is a rare form of TC. The aim of this study was to review epidemiological, clinical and mycological profile of inflammatory TC. We present a retrospective study (1999-2010), enrolled all the cases of inflammatory TC observed at a referral hospital in the northern Tunisia. One hundred and twenty-one patients with inflammatory TC, 83 male patients (68.6%) and 38 female patients (31.4%) were enrolled. The mean age was about 8 years. A majority of TC (71.9%) were in patients lesser than 10 years of age. Positive family history and contact with animals were noted in seven and 35 cases respectively. Direct examination was positive in 110 cases (59 ectothrix, 51 endothrix) and positive cultures were obtained in 105 patients (49 Trichophyton violaceum, 31 Microsporum canis, 13 Trichophyton interdigitale complex, 12 Trichophyton verrucosum). Systemic treatment was carried out in 115 patients with griseofulvin, in one with terbinafine. A complete recovery was noted in 88 cases; and persistent alopecia in 28 cases. The inflammatory TC is rare, but more common in rural families. The disease mostly affected male genders (68.6%) and T. violaceum remains the common pathogen of inflammatory TC in northern Tunisia.

Tinea capitis: predictive value of symptoms and time to cure with griseofulvin treatment

OBJECTIVES

To describe (a) the predictive value of symptoms for diagnosis of tinea capitis and (b) the rate and timing of cure with high-dose griseofulvin treatment.

METHODS

This prospective open-label study enrolled children aged 1 to 12 years with clinical tinea capitis. Participants with a positive dermatophyte culture received oral griseofulvin (20-25 mg/kg/day) and topical selenium sulfide shampoo for 6 weeks. Main outcome measures. The rate of symptoms of tinea capitis, and rates of mycologic and clinical cure.

RESULTS

The positive predictive values of any 1, 2, 3, or 4 symptoms for a positive culture were 88%, 82%, 78%, and 77%, respectively. The observed rates of mycologic, clinical, and complete cure were 89%, 66%, and 49%, respectively. conclusion: In a high-risk population it is reasonable to diagnose tinea capitis using one or more cardinal symptoms. Oral griseofulvin at 20 to 25 mg/ kg/day with adjunctive shampooing for 6 weeks is moderately successful as treatment.

Epidemiology of dermatophytoses in Sfax, Tunisia

The distribution of dermatophytes varies in different countries and geographical areas depending on several factors. To determine the frequency of aetiological agents and the clinical variants of dermatophytoses, we carried out a study between 1998 and 2007. Out of 25 432 subjects suspected to have superficial mycoses, 9960 (39.2%) were affected with dermatophytoses; 14957 positive samples were obtained. The mean age was 35.7 years (range: 21 days to 97 years). Sex ratio was 0.9. Our patients were from urban regions in 81.9% of cases. The most common type of infection was onychomycosis (30.3%), followed by tinea pedis (24.8%), intertrigo (21.7%), tinea corporis (11.4%) and tinea capitis (9.6%). Fifteen patients had generalised dermatophytosis. Hadida and Schousboe disease was diagnosed in one case with lethal evolution. The most isolated dermatophyte was Trichophyton rubrum (74.5%), followed by T. violaceum (7.9%), T. mentagrophytes (7.5%), Microsporum canis (3.8%), Epidermophyton floccosum (0.7%) and T. verrucosum (0.54%). Other species were occasionally isolated: T. schoenleinii, T. tonsurans, M. audouinii and M. ferrugineum. The prevalence of dermatophytoses remains high in our country (996 cases/year). Trichophyton rubrum is the predominant causal agent. However, zoophilic agents become more prevalent. Epidemiological surveys are an essential tool for developing strategies for infection control.

The emergence of Trichophyton tonsurans in Port-au-Prince, Haiti

The occurrence of the anthropophilic dermatophyte Trichophyton tonsurans as a frequent causative agent of tinea capitis in several developed countries has been associated with a global rise in its isolation during recent years. While T. tonsurans was never found in Haiti before 1988, a sharp increase in the number of isolates of this species from scalp lesions began to be observed in 2005 in Port-au-Prince, Haiti. A prospective study was conducted in Port-au-Prince from May to November 2006 of 64 children presenting with tinea capitis at the dermatological outpatient clinic of the university hospital. Forty-five (70%) were male and 19 female (30%), with an average age at presentation of 6.1 years (age range 1-16 years). Direct microscopic examination of scalp hair using 10% potassium hydroxide was positive in 93.8% and culture confirmation was established in 55 cases (85.9%). Five species of dermatophytes were identified, with the anthropophilic dermatophyte T. tonsurans, accounting for the majority or 35 (63.6%) of all cases of tinea capitis. Other dermatophyte species identified included T. mentagrophytes (14.5%), Microsporum audouinii (12.7%), T. rubrum (7.3%) and in one case, the geophilic M. gypseum (1.8%). In two cases caused by T. tonsurans skin involvement on other areas of the body was recorded. The most frequent pathogen in tinea capitis is now T. tonsurans in Port-au-Prince. We speculate that the recent emergence of T. tonsurans in Haiti is linked to the dramatically increasing mobility of Haitian Diaspora.

Rapid identification of Trichophyton tonsurans by specific PCR based on DNA sequences of nuclear ribosomal internal transcribed spacer (ITS) 1 region

BACKGROUND

Trichophyton tonsurans, a dermatophyte implicated in an international epidemic of tinea capitis, was also found to be responsible for infecting wrestling and Judo athletes nationwide in Japan since 2001.

OBJECTIVE

A rapid and highly accurate means of identifying this pathogen has been required to control the infection. We have developed a T. tonsurans-specific PCR method based on the DNA sequences of the nuclear ribosomal internal transcribed spacer 1 region.

SUBJECTS

Eighteen species of six genera of standard strains and 75 strains of clinically isolated Trichophyton species were used in this study.

METHODS

A T. tonsurans-specific PCR primer pair (tonsF1 and tonsR1) was designed on the nuclear ribosomal internal transcribed spacer 1 region, located between 18S and 5.8S rDNA. Fungal DNA was extracted from the colonies grown on culture plates, and the specificity of the PCR primers was tested.

RESULTS

The specific PCR product was amplified from the standard strain of T. tonsurans and from five strains isolated from black dot ringworms, but there was no band from the 70 clinical isolates of other Trichophyton species. This T. tonsurans-specific PCR method was able to detect 10 pg of T. tonsurans genomic DNA with ethidium bromide staining.

CONCLUSIONS

A PCR identification system specific for T. tonsurans is rapid, sensitive, and specific.

Real-time PCR TaqMan assay for detectingTrichophyton tonsurans, a causative agent of tinea capitis, from hairbrushes

Tinea capitis caused by Trichophyton tonsurans is currently an epidemic in the United States, Europe, and Japan, and the cultivation of this microorganism is necessary for a definitive diagnosis. We recently developed a real-time PCR TaqMan assay as a culture-independent method for the rapid detection of T. tonsurans from hairbrushes.

Pharmacokinetics of terbinafine in young children treated for tinea capitis

BACKGROUND

Dermatophytes are the most common cause of human fungal infections. Response rates to existing therapy are lower than optimal, but newer agents like terbinafine hold promise for improved management of such infections. This investigation was designed to evaluate the single dose and steady state pharmacokinetics of terbinafine in young children with tinea capitis.

METHODS

Twenty-two otherwise healthy children (4-8 years) with tinea capitis were eligible for enrollment. Children were treated with terbinafine once daily according to body weight (<25 kg, 125 mg; 25-35 kg, 187.5 mg), and pharmacokinetic sampling was conducted after the first dose, at the midpoint of treatment and at steady state. Plasma terbinafine concentrations were quantitated, and the pharmacokinetic indices compared with adult data.

RESULTS

Absolute estimates of Cmax and area under the concentration curve (AUC)0-24 were comparable between children and adults for the administered dose; however, children demonstrated significantly lower estimates of exposure when dose was corrected for weight (Cmax SS 200 +/- 104 versus 454 +/- 185 ng/mL per mg/kg dose, P < 0.01; AUCSS: 1110 +/- 640 versus 2756 +/- 1775 ng*h/mL per mg/kg dose, P < 0.01). When examined along a continuum, age accounted for approximately 50% of the variability observed in dose-normalized Cmax and AUC (P < 0.01). A slight but significant reduction in apparent oral clearance was observed with increasing age (0.02 L/h/kg per yr) that likely accounts for the lesser degree of accumulation observed in children at steady state (accumulation ratio, 1.5 +/- 0.8 versus 2.3 +/- 0.6, P < 0.01). Adverse events consisted principally of headache (n = 3) and gastrointestinal complaints (altered eating habits n = 3, loss of appetite n = 3, stomachache n = 4, diarrhea n = 2). A reduction in neutrophil count was observed in 5 children and thought to be related to study drug in 2.

CONCLUSIONS

Children require significantly larger weight-normalized doses to approximate the exposure estimates observed in adults. The dosing scheme used in this investigation results in absolute exposure estimates at steady state and a safety profile that are not appreciably different from adults.

Allergy and dermatophytes

Tinea pedis (athlete's foot) and onychomycosis (infection of the toenails) caused by the dermatophyte fungus Trichophyton are highly prevalent in adults. Several Trichophyton allergens have been identified based on elicitation of immunoglobulin E antibody-mediated immediate-hypersensitivity (IH) responses. Evidence of an etiologic role for Trichophyton in asthma in some subjects with IH and chronic dermatophytosis is provided by bronchial reactivity to Trichophyton. Improvement of asthma after systemic antifungal treatment corroborates this link. A unique feature of Trichophyton allergens is the ability of the same antigen to elicit delayed-type hypersensitivity (DTH) in individuals who lack IH reactivity. Delayed responses appear to confer protection, while IH responses do not, based on the association with acute versus chronic skin infection. The amino acid sequence identity of Trichophyton allergens with diverse enzyme families supports a dual role for these proteins in fungal pathogenesis and allergic disease. Characterizing the immunologic properties of Trichophyton allergens and defining immune mechanisms which drive dichotomous responses are pivotal to understanding the dermatophyte-allergy relationship. Recent studies have identified DTH-associated major T-cell epitopes which could facilitate the development of peptide vaccines. Characterization of additional molecular targets by using new techniques may aid not only in the eradication of infection but also in the resolution of allergic symptoms.

Optimal management of fungal infections of the skin, hair, and nails

Superficial fungal infections are chronic and recurring conditions. Tinea capitis is a scalp infection, primarily affecting prepubescent children. Ringworm infections, such as tinea corporis and tinea cruris, involve the glabrous skin. Tinea nigra is a rare mycotic infection that may be related to travel abroad. Piedra, black or white, is limited to the hair shaft without involvement of the adjacent skin. Pityriasis (tinea) versicolor and seborrheic dermatitis are dermatoses associated with yeasts of the genus Malassezia that affect the lipid-rich areas of the body. The taxonomy of the Malassezia yeasts has been revised to include nine species, eight of which have been recovered from humans. Tinea pedis, an infection of the feet and toes, is one of the most common forms of dermatophytosis. Onychomycosis is a fungal infection affecting the nail bed and nail plate; it may be chronic and can be difficult to treat. In instances where the superficial fungal infection is severe or chronic, an oral antifungal agent should be considered. Terbinafine, itraconazole, and fluconazole are oral antifungals that are effective in the treatment of superficial mycoses.

Epidemiologic surveillance of cutaneous fungal infection in the United States from 1999 to 2002

BACKGROUND

Cutaneous fungal infections are common in the United States, and causative organisms include dermatophytes, yeasts, and nondermatophyte molds. These organisms are in constant competition for their particular environmental niche, often resulting in the emergence of one or more predominant pathogens and displacement of other less competitive species. Changes in the incidence of fungal pathogens can be followed from laboratory culture results of infected cutaneous tissues over time. These data can be used to ascertain past and present trends in incidence, predict increases in antifungal resistance and the adequacy of our current pharmacologic repertoire, and provide insight into future developments.

OBJECTIVE

This study identifies epidemiologic trends and the predominant organisms causing superficial fungal infections in the United States.

METHODS

A total of 15,381 specimens were collected from clinically suspected tinea corporis, tinea cruris, tinea capitis, tinea faciei, tinea pedis, tinea manuum, and finger and toe onychomycosis from 1999 through 2002. Specimens were submitted to the Center for Medical Mycology in Cleveland, Ohio, for fungal culture and identification, and the incidence of each species was calculated.

RESULTS

Dermatophytes remain the most commonly isolated fungal organisms except from clinically suspected finger onychomycosis, in which case Candida species comprise >70% of isolates. Trichophyton rubrum remains the most prevalent fungal pathogen, and increased incidence of this species was observed in finger and toe onychomycosis, tinea corporis and tinea cruris, tinea manuum, and tinea pedis. As the causal agent of tinea capitis, T tonsurans continues to increase in incidence, achieving near exclusionary proportions in the United States.

CONCLUSION

Consideration of the current epidemiologic trends in the incidence of cutaneous fungal pathogens is of key importance to investigational efforts, diagnosis, and treatment.

The efficacy and safety of terbinafine in children

Terbinafine is an allylamine antifungal agent that has been effective and safe in the treatment of superficial and some deep mycotic infections in adults. An increasing amount of data is available where terbinafine has been used in the paediatric population to treat superficial fungal infections, in particular tinea capitis. The data suggest that terbinafine is effective and safe using treatment regimens that involve short duration therapy, leading to an increased compliance and providing a cost-effective means of treating paediatric superficial fungal infections such as tinea capitis. Terbinafine has been approved for the treatment of tinea capitis in many countries worldwide, and provides good efficacy rates for Trichophyton tinea capitis using shorter regimens than the gold standard griseofulvin. The adverse events profile for children is similar to that in adults with few adverse effects associated with its use. The evidence favours the use of terbinafine in the treatment of superficial infections in children.

Superficial fungal infections: an update on pityriasis versicolor, seborrheic dermatitis, tinea capitis, and onychomycosis

The recent advances in pityriasis versicolor, seborrheic dermatitis, tinea capitis and onychomycosis are reviewed. Some highlighted points include the new classification of Malassezia species, and the association of Malassezia species with seborrheic dermatitis. The use of terbinafine, fluconazole, and itraconazole for the treatment of tinea capitis is discussed. The management of onychomycosis, highlighting the high efficacy rates obtained with terbinafine when used to treat dermatophyte toenail onychomycosis, is discussed. The use of combination therapies in some circumstances to maximize cure rates is reviewed.

The efficacy and safety of terbinafine in children

In summary, terbinafine is a broad-spectrum allylamine, which has been used to treat superficial fungal infections including onychomycosis, and some systemic mycoses in adults. With a fungicidal activity, low minimum inhibitory concentration value, and high selectivity for fungal squalene epoxidase, terbinafine has demonstrated good efficacy in superficial fungal infections. Its lipophilic nature provides excellent, widespread absorption into hair, skin, and nails where it can eradicate fungal infection. Terbinafine has been shown to be effective and safe in several studies of the treatment of tinea capitis and onychomycosis in children. When treating Trichophyton tinea capitis the length of therapy may be 2 or 4 weeks. Microsporum tinea capitis may require somewhat higher or longer doses of terbinafine for adequate efficacy. These regimens still tend to be shorter than treatment with griseofulvin, and terbinafine may provide a higher compliance and a more cost-effective means of managing tinea capitis. It is possible that even higher cure rates and a shorter duration of therapy may be achieved following further optimization of treatment regimens that use a higher daily dosage of terbinafine than is currently recommended. The evidence is strongly in favor of using terbinafine to treat superficial fungal infections in children.

Case Reports. Tinea capitis due to Trichophyton soudanense and Trichophyton schoenleinii

Four cases of tinea capitis, two due to Trichophyton soudanense in Italian children who had had contact with Africans, and two due to Trichophyton schoenleinii in an African and an Italian child, respectively, are reported. Infections caused by anthropophilic dermatophytes are rare in Italy and are related to immigration. The most frequent agents of tinea capitis in Italy are zoophilic dermatophytes.

Variation in restriction fragment length polymorphisms among serial isolates from patients with Trichophyton rubrum infection

Molecular genotyping of strains of Trichophyton rubrum and T. mentagrophytes from patients with onychomycosis of the toes was performed to ascertain whether the fungal genotype changes over the course of time as sequential samples were obtained from patients receiving antifungal therapy and during follow-up. Sixty-six serial strains of T. rubrum and 11 strains of T. mentagrophytes were obtained from 20 patients (16 patients with T. rubrum, 4 with T. mentagrophytes) who were treated with oral antifungal therapy and observed over periods of up to 36 months. These strains were screened for genetic variation by hybridization of EcoRI-digested genomic DNAs with a probe amplified from the small-subunit (18S) ribosomal DNA and adjacent internal transcribed spacer regions. A total of five restriction fragment length polymorphism (RFLP) types were observed among 66 strains of T. rubrum. Two major RFLP types, differentiated by one band shift, represented 68% of the samples. None of the patients had a unique genotype. More than one RFLP type was often observed from a single patient (same nail) over a period of 1, 2, or 3 years, even in cases that did not appear cured at any time. Samples taken from different nails of the same patient had either the same or a different genotype. The genotypic variation did not correspond to any detectable phenotypic variation. Furthermore, no correlation was observed between the efficacy of the treatment administered and the genotype observed. While the DNA region studied distinguished among T. rubrum, T. mentagrophytes, and T. tonsurans, intraspecific RFLP variation was observed for T. rubrum and T. mentagrophytes strains. While independent multiple infection and coinhabitation of multiple strains may explain the presence of different genotypes in a nail, microevolutionary events such as rapid substrain shuffling, as seen in studies of repetitive regions in Candida species, may also produce the same result. The recovery of multiple strains during the course of sequential sampling of uncured patients further suggests that the typing system is not able to distinguish between relapse or reinfection, ongoing infection, and de novo infection.

Tinea capitis

Tinea capitis is a common dermatophyte infection of the scalp in children. Dermatophytes are classified into three genera; tinea capitis is caused predominantly by Trichophyton or Microsporum species. On the basis of host preference and natural habitat, dermatophytes are also classified as anthropophilic, geophilic and zoophilic. The etiological agents of tinea capitis usually fall in the first and last categories. In North America, tinea capitis is now predominantly due to Trichophyton tonsurans. During the past 100 years the most common North American organism for tinea capitis was initially Microsporum canis followed later by M. audouinii. In other parts of the world the epidemiology varies. Tinea capitis is generally observed in children over the age of 6 years and before puberty, with African Americans being the most affected group. Clinical presentations are seborrheic-like scale, 'black dot' pattern, inflammatory tinea capitis with kerion and tiny pustules in the scalp. The clinical diagnosis should be confirmed by mycological examination. Wood's light examination was of value in diagnosing tinea capitis due to M. canis and M. audouinii; however, it is not helpful in T. tonsurans tinea capitis. Asymptomatic carriers may be a significant reservoir of infection and spread of spores may also involve inanimate objects. Carriers may benefit from shampooing their hair. Treatment of tinea capitis requires an oral antifungal agent. The data from the use of terbinafine, itraconazole and fluconazole are promising and suggest that these agents have an efficacy similar to griseofulvin while shortening the duration of therapy. Both griseofulvin and the newer antimycotics have a favorable adverse-effect profile and are associated with high compliance.

Tinea capitis: current concepts

Tinea capitis is an important fungal infection that may at times be a clinical, diagnostic and therapeutic challenge. It is common in childhood around the world, becoming almost epidemic in some communities. The central European and American experience with it is somewhat variable, due to different etiologic fungi. The use of topical antifungal agents and other approaches is stressed as of value alongside the use of systemic antifungal medication.

Tinea capitis: an overview with emphasis on management

Tinea capitis is perhaps the most common mycotic infection in children. In North America the epidemiology of tinea capitis has changed so that Trichophyton tonsurans now predominates over Micro-sporum audouinii. With this transition the utility of the Wood's light for diagnosis has been reduced since T. tonsurans infection is Wood's light negative. Griseofulvin has been the mainstay of therapy for the last 40 years. The newer antifungal agents-itraconazole, terbinafine, and fluconazole-appear to be effective and safe for the treatment of tinea capitis. When tinea capitis is due to T. tonsurans or other endothrix species the following regimens have been used: itraconazole continuous regimen (5 mg/kg/day for 4 weeks), itraconazole pulse regimen with capsules (5 mg/kg/day for 1 week plus 1-3 pulses 3 weeks apart), and itraconazole pulse regimen with oral solution (3 mg/kg/day for 1 week plus 1-3 pulses 3 weeks apart). With terbinafine tablets the continuous regimen (>40 kg body weight, 250 mg/day; 20-40 kg, 125 mg/day; and <20 kg, 125 mg/day) is given for 2 to 4 weeks. Fluconazole tablets or oral suspension (6 mg/kg/day) were administered for 20 days in one trial. Another possibility may be 6 mg/kg/day for 2 weeks and evaluating the scalp 4 weeks later. An extra week of therapy (6 mg/kg/day) can be administered if clinically indicated at that time. A once-weekly regimen may also be effective. When ectothrix organisms (e.g., Microsporum canis) are present, a longer duration of therapy may be required. The data suggest that the newer agents are effective, safe with few adverse effects, and have a high benefit:risk ratio. It remains to be seen to what extent griseofulvin will be superseded for the treatment of tinea capitis. Adjunctive therapies may help decrease the risk of infection to other individuals. Appropriate measures should be taken to reduce the possibility of reinfection.