A survey of dermatophytes isolated from human patients in the United States from 1979 to 1981 with chronological listings of worldwide incidence of five dermatophytes often isolated in the United States

Dermatophytosis caused by Nannizzia nana (Microsporum nanum): a comprehensive review on a novel pathogen

Keratinophilic fungi are mostly soil-inhabiting organisms with occasional infections in humans and animals. Even though most dermatophytes are host-adapted, cross-species infections are common by zoophilic and geophilic dermatophytes. N. nana is considered an etiological agent of ringworm in pigs but has also been isolated from other animals, including humans. However, it also possesses many characteristics of geophilic dermatophytes including the ability to grow in soil. N. nana produces characteristic pear-shaped macroconidia and usually exhibits an ectothrix pattern of hair infection. It has been isolated from dermatitis lesions as well as from soil. N. nana infections in pigs are not of much concern as far as economy or health is concerned. But it has been associated with onychomycosis and gonathritis in humans, which are significant in human medicine. The shift in the predominance of dermatophytes in humans and the ability to evolve into a potential tinea pathogen necessitates more understanding of the physiology and genetics of N. nana. In this review, we have attempted a detailed analysis of the studies about N. nana, emphasizing growth and cultural characters, physiology, isolation, infection in humans and animals, molecular characterization and antifungal susceptibility.

Tinea capitis: A single-institution retrospective review from 2010 to 2015

BACKGROUND/OBJECTIVE

Tinea capitis is a common infection of scalp hair in children. The prevalent etiologic organism has changed significantly over time, which may reflect the complex interaction of environmental factors, genetic predisposition, and movement of populations. We evaluate the prevalence of different infectious organisms causing tinea capitis and describe the clinical characteristics.

METHODS

A retrospective chart review of patients diagnosed with tinea capitis with tissue culture confirmation, who were seen in pediatric dermatology at a tertiary care center from 2010 to 2015. Patient demographics, culture data, and clinical characteristics were evaluated. Inflammatory pattern, characterized by presence of pustules, bogginess, or lymphadenopathy, was noted.

RESULTS

Forty-six patients with culture-positive tinea capitis were identified. In the 18 (42.9%) patients who were infected with either Trichophyton violaceum or Trichophyton soudanenese, all were of African ethnicity. In contrast, Trichophyton tonsurans was identified in a minority of African patients (3.8%), revealing a statistically significant difference between ethnicity and infective species (P-value < 0.001). T tonsurans was significantly more likely than T violaceum to exhibit an inflammatory pattern (68% vs 22%, P value < 0.027).

CONCLUSIONS

While T tonsurans remained the most common cause of tinea capitis, T violaceum and T soudanense have increased in prevalence. As these latter agents are less inflammatory, clinical diagnosis may be delayed. Studying changes in the infectious cause of tinea capitis can help us create a snapshot to better understand the evolution of our population make-up, allowing us to provide crucial quality health care to all.

Eighty Years of Mycopathologia: A Retrospective Analysis of Progress Made in Understanding Human and Animal Fungal Pathogens

Mycopathologia was founded in 1938 to 'diffuse the understanding of fungal diseases in man and animals among mycologists.' This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5-5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of 'classic papers' since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host-pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other's language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond.

Human Infections with Microsporum gypseum Complex (Nannizzia gypsea) in Slovenia

Microsporum gypseum complex is a group of geophillic dermatophytes with a worldwide distribution and is a rare cause of dermatomycoses in humans. The infection most commonly presents as tinea corporis, with some geographical and occupational variations. We studied M. gypseum complex infections in patients examined in the Mycological Laboratory of the Department of Dermatovenereology, University Medical Centre Ljubljana, during the period 2000-2015. Diagnosis was confirmed by mycological examination. Skin scales were examined by direct microscopy and cultivated on Sabouraud glucose agar. A total of 226 patients were identified, representing 1.5% of all dermatophyte infections during the study period. Tinea corporis was diagnosed in majority of patients, followed by tinea manus, tinea faciei, tinea inguinalis and tinea pedis. Tinea capitis was observed in three and onychomycosis in two patients only. Infection was disseminated on different parts of the body in nine patients. In 39% of patients, infection was diagnosed in children younger than 9 years. Face and scalp infection was more often observed in children. The incidence was the highest during July and October. Contacts with soil and domestic animals were often reported. Data on the prevalence and clinical characteristics of M. gypseum complex infection in other countries are reviewed.

The Changing Face of Dermatophytic Infections Worldwide

Dermatophytes evolve along with the geography and socioeconomic conditions. Epidermophyton floccosum, Microsporum audouinii and Trichophyton schoenleinii acted as the major pathogens of superficial fungal diseases 100 years ago, but their frequency decreased dramatically since the middle of the twentieth century and they are limited to some less-developed countries nowadays; meanwhile, frequency of Trichophyton rubrum, Trichophyton interdigitale, Trichophyton tonsurans and Microsporum canis increased gradually, and these fungi have become the major species globally. Some other dermatophytes, i.e., Trichophyton violaceum, Trichophyton verrucosum and Microsporum ferrugineum, are mainly endemic in some parts of Africa, Asia and Europe. At present, T. rubrum is the leading pathogen for skin and nail fungal infections, whereas M. canis, T. tonsurans and T. violaceum present as the predominant dermatophytes involved in tinea capitis. Population mobility, changes in human lifestyle and advents of antifungal drugs will continually drive the dermatophyte evolution in the skin microenvironment. Comprehensive observation is needed to better understand this kind of organisms and prospect the trends of their changes in future.

Unusual Species of Dermatophytes: Rarely Identified or New?

Dermatophytes are causing superficial mycosis in animals and humans. Depending on the geophilic, zoophilic or anthropophilic origin of the fungus but also on the immunological status of the patient, symptomatology can widely differ. Nevertheless, each species is currently associated with typical clinical manifestations, even if atypical localizations and/or clinical pictures are sometimes also reported. Diagnostic tools applied to species identification have been changing since the last two decades with the more frequent use of molecular methods currently considered nowadays as reference methods for species identification. It becomes obvious that the algorithm used for the distinction of closely related species needs to combine phenotypic and genomic methods. All these different points are discussed, and the most recent novel species causing or involved in human dermatophytosis are reported.

Bayesian analysis of two diagnostic methods for paediatric ringworm infections in a teaching hospital

Quantitatively, conventional methods of diagnosis of tinea capitis or paediatric ringworm, microscopic and culture tests were evaluated with Bayes rule. This analysis would help in quantifying the pervasive errors in each diagnostic method, particularly the microscopic method, as a long-term treatment would be involved to eradicate the infection by the use of a particular antifungal chemotherapy. Secondly, the analysis of clinical data would help in obtaining digitally the fallible standard of the microscopic test method, as the culture test method is taken as gold standard. Test results of 51 paediatric patients were of 4 categories: 21 samples were true positive (both tests positive), and 13 were true negative; the rest samples comprised both 14 false positive (microscopic test positivity with culture test negativity) and 3 false negative (microscopic test negativity with culture test positivity) samples. The prevalence of tinea infection was 47.01% in the population of 51 children. The microscopic test of a sample was efficient by 87.5%, in arriving at a positive result on diagnosis, when its culture test was positive; and, this test was efficient by 76.4%, in arriving at a negative result, when its culture test was negative. But, the post-test probability value of a sample with both microscopic and culture tests would be correct in distinguishing a sample from a sick or a healthy child with a chance of 71.5%. However, since the sensitivity of the analysis is 87.5%, the microscopic test positivity would be easier to detect in the presence of infection. In conclusion, it could be stated that Trychophyton rubrum was the most prevalent species; sensitivity and specificity of treating the infection, by antifungal therapy before ascertaining by the culture method remain as 0.8751 and 0.7642, respectively. A correct/coveted diagnostic method of fungal infection would be could be achieved by modern molecular methods (matrix-assisted laser desorption ionisation-time of flight mass spectrometry or fluorescence in situ hybridization or enzyme-linked immunosorbent assay [ELISA] or restriction fragment length polymorphism or DNA/RNA probes of known fungal taxa) in advanced laboratories.

A case of fungal keratitis and onychomycosis simultaneously infected by Trichophyton species

BACKGROUND

Fungal keratitis is difficult to treat that can result in corneal blindness requiring penetrating keratoplasty and in fungal endothalmitis. We report a case of fungal keratitis and onychomycosis simultaneously infected by Trichophyton.

CASE PRESENTATION

A 77-year old male presented with ocular pain, conjunctival injection, and severe loss of vision in his left eye. His best corrected visual acuity was hand movements in the left eye, and slit-lamp examination showed a corneal ulcer with feathery margin and hypopyon. Bacterial and fungal smear/culture showed no organism, and there was no improvement in spite of treatment with topical fortified 5% cefazolin and 2% tobramycin. Trichophyton species was identified by repeated cultures. We found onychomycosis on the patient's foot, where the same fungal species were identified. Regimen was changed to topical itraconazole and systemic intravenous itraconazole. No clinical improvement was observed, so therapeutic penetrating keratoplasty and cryotherapy was done with continuation of antifungal therapy. The graft was clear at postoperative 1 month and no evidence of recurrence was found.

CONCLUSION

It is important to identify the pathogen of keratitis because early identification of pathogen causing keratitis provides the appropriate treatment in early phase of keratitis. It is necessary to search for other fungal skin infections such as onychomycosis and athelete's foot considering the fungal keratitis following skin infection. In addition, fungal skin infection including onychomycosis should be treated for prevention of fungal keratitis as soon as possible.

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.

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.

Tinea capitis among primary school children in Anambra state of Nigeria

Tinea capitis continues to be a common problem of infancy and childhood, particularly among those living in unhygienic crowded conditions. The prevalence and aetiology of tinea capitis have not been well defined in Anambra state of Nigeria - hence the need to undertake this study. A total of 47,723 primary school children residing in different regions of the State was screened for tinea capitis between 2002 and 2005. Of this number, 4498 (9.4%) had tinea capitis. The highest prevalence of the disease occurred in the Southern region of the state (12.6%). Schools in urban areas recorded lower prevalence of the disease. Male : female prevalence ratio of 1.6 : 1 was recorded. Tinea capitis occurred significantly more in children below 10 years of age than in those above this age (chi(2 )= 3.178; P < 0.10). Of 502 isolates recovered in culture, Microsporum audouinii was the most prevalent (42%), followed by M. ferrugineum (17%) and Trichophyton mentagrophytes (16%). Four of the samples revealed spore head of Aspergillus spp. in direct sample microscopy. A total of 29 (6%) isolates was atypical forms. The majority (91%) of children with the lesion came from families of three or more children, living in crowded apartments. Results showed that tinea capitis remains an important public health problem in Anambra state of Nigeria.

Analysis of the dermatophyte species isolated in the British Isles between 1980 and 2005 and review of worldwide dermatophyte trends over the last three decades

Infections of the skin, hair and nails by dermatophyte fungi are common in developed and developing countries alike. However, the species involved and the resulting clinical entities vary both geographically and with time. We have surveyed 15,333 dermatophytes obtained from primary isolations at the Mycology Reference Laboratory, Bristol, UK from 1980 through 2005. Several striking trends in dermatophyte prevalence were apparent over this period. The relative frequencies of isolations of Microsporum canis (cat and dog ringworm), Trichophyton verrucosum (cattle ringworm), T. mentagrophytes var. mentagrophytes (rodent ringworm) and Epidermophyton floccosum (a cause of human groin and foot infections) all decreased by 90%. Conversely, the contributions of T. tonsurans and T. violaceum (two anthropophilic scalp-infecting species) to total dermatophyte isolations increased by 1000% over the same period. Finally, T. rubrum and T. mentagrophytes var. interdigitale, the two common causes of foot infection comprised 80% of all dermatophytes isolated in 1980 and 90% of isolations in 2005. Similar trends in dermatophyte prevalence were evidenced throughout the British Isles, based on the voluntary reporting of isolations from a large number of British laboratories at 5-yearly intervals over the same period. The implications of these changing patterns of dermatophyte species, and the clinical entities they produce are discussed in the context of a review of worldwide dermatophyte isolations over the last three decades, with emphasis on the causal agents of tinea capitis.

Isolation of Trichophyton violaceum and Trichophyton soudanense in Baltimore, Maryland

Tinea capitis is of public health importance because of its transmissibility. Trichophyton violaceum and Trichophyton soudanense, which are common causes of tinea capitis in parts of Africa and West Asia, have only rarely been reported to cause dermatophytoses in the United States. We identified 24 patients with 25 positive cultures for T. violaceum or T. soudanense that were processed in a single hospital laboratory in Baltimore, Maryland, between 1 January 2000 and 30 June 2006. Most patients for whom clinical information was available had tinea capitis. There was a marked increase in the isolation of these organisms between the period from 2000 to 2002 and the period from 2003 to 2006, possibly associated with changes in immigration to the Baltimore metropolitan area. The changing epidemiology of this transmissible fungal infection not only is of public health interest as an example of the introduction of a "new" pathogen to an area where it traditionally was not endemic but also is of clinical and microbiological importance given reports suggesting an increasing incidence of tinea capitis in some areas and increasing clinical failure rates of current therapies.

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.

Trichophyton Fungal Keratitis

OBJECTIVE

To report 5 cases of fungal keratitis caused by Trichophyton schoenleinii.

METHODS

Case reports.

RESULTS

Trichophyton schoenleinii is responsible for aggressive fungal keratitis that is associated with keratolysis as a result of collagenase expression by the organism. Clinically, the organism seems to be sensitive to topical natamycin but resistant to topical amphotericin B and miconazole. Two patients achieved clinical cures with medical therapy alone, but with visual outcomes of only 20/125 and hand motions because of corneal scarring. Two patients achieved clinical cures with therapeutic penetrating keratoplasty (PKP), which remained clear and provided final visual outcomes of 20/60 and 20/200. One patient developed fungal scleritis and panophthalmitis despite 2 therapeutic PKPs and required enucleation.

CONCLUSION

Trichophyton schoenleinii is a rare cause of fungal keratitis that may be associated with progressive keratolysis and perforation, scleral extension, and endophthalmitis. Therapeutic keratoplasty may be successful in achieving cure in medically unresponsive cases.

The epidemiology of Microsporum canis infections in Rijeka area, Croatia. Die Epidemiologie der Microsporum canis-Infektionen in der Region Rijeka, Kroatien

The aim of the study was to analyze the Microsporum canis infections in the Rijeka area, Croatia, observed between 1990 and 2001. A total of 724 cases of dermatophytosis caused by M. canis were diagnosed in 320 individuals with the tinea capitis and 404 with tinea corporis. The M. canis infections constituted 32.8% of all dermatophytes isolated during the study period.

Tinea capitis favosa in Poland. Fallberichte. Tinea capitis favosa in Polen

Tinea capitis favosa is uncommon in Europe. We describe two patients who had local alopecia caused by Trichophyton schoenleinii. In the first case, we observed good clinical response after griseofulvin treatment and in the second case after topical application of ciclopirox cream.

The pustular disorders

The pustular disorders constitute a subgroup of the vesiculobullous disorders defined by the presence of eosinophils or neutrophils with prominent accompanying intercellular edema or a canthelysis involving various levels of the epithelium. Herein, we describe the clinical and pathologic attributes of the subcorneal, infectious, neonatal, papulosquamous, drug-induced and miscellaneous pustular conditions.

A study of dermatophytoses in Sana'a, Yemen Republic

The present study describes the extent and causative agents of dermatophytoses in Sana'a, the capital of Yemen Republic. Out of 1100 patients with various skin diseases, 16.6% were affected with dermatophytoses. Among them, 70% were male and the age group 11-20 years was most susceptible to tinea infections. Tinea corporis was the most common disease, followed by tinea capitis. One hundred and seventy isolates of dermatophytes related to 9 species were identified. Microsporum canis was the most prevalent species, followed by Trichophyton violaceum.

Subcutaneous infection by Microsporum gypseum

We report a case of subcutaneous infection caused by the dermatophyte Microsporum gypseum in an immunocompetent host. The patient acquired the infection in the knee through a traumatic inoculation of a splinter. To our knowledge this is the first case of subcutaneous infection caused by this fungus.

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.

A survey of dermatophytes isolated from human patients in the United States from 1993 to 1995

A survey of dermatophytes, isolated from human patients seeking medical attention, was conducted for the years 1993 to 1995. Data were collected from 23 states throughout the continental United States and the District of Columbia and from 44 to 45 laboratories. These data were compared with the results of two earlier surveys (1979 to 1981 and 1985 to 1987). In contrast to the earlier surveys Trichophyton tonsurans became the most frequently isolated dermatophyte (44.9%) followed by T. rubrum (41.3%), T mentagrophytes (8.5%), Microsporum canis (3.3%) and Epidermophyton floccosum (1.1%). Other dermatophytes were recovered from less than 1%. The increase in T. tonsurans from 27.9% in the 1979 to 1981 survey, to 41.3% in the current survey, accompanied by the decline of T. rubrum from 53.7% to 41.3% is statistically significant (P < .001)

Frequency of dermatophytes in the metropolitan area of Porto Alegre, RS, Brazil

In order to evaluate the distribution of dermatophytes in Porto Alegre, the capital of the state of Rio Grande do Sul, Brazil, they were isolated from the skin, hairs and nails samples and retrospectively analyzed from June 1981 to June 1995, in two different institutions in the city of Porto Alegre: (i) the Serviço de Micologia do Instituto de Pesquisas Biológicas Jandyr Maya Faillace, da Secretaria de Saúde e Meio Ambiente do Rio Grande do Sul which attends the low income population (low and middle classes) and, (ii) Laboratório Weinmann, a clinical pathology laboratory which attends predominantly the higher income population (middle and upper classes), both which attend in the metropolitan area of Porto Alegre. The dermatophyte predominance of Trichophyton rubrum was confirmed (55.33%) followed by T. mentagrophytes (21.46%). The data obtained were compared with the existing prevalence data which were collected in the interior of the state over a period of 32 years (1960-1992). T. verrucosum, T. simii, Microsporum persicolor, T. schöenleinii, M. nanum and M. cookei were isolated in the interior and have not been found in the capital so far. On the other side, T. violaceum was, isolated in the capital and has not been found in the interior so far.

Isolation of Microsporum nanum from a patient with tinea corporis in Madras, India

Microsporum nanum was isolated from a case of tinea corporis in a 16-year-old boy. This is the first recorded case of human ringworm infection caused by M. nanum in India.

Some aspects of dermatophytoses seen at University Hospital in Florianópolis, Santa Catarina, Brazil

Dematophytoses comprise mycoses which are very frequently diagnosed in the routine of clinical laboratories of Florianópolis, like any other Brazilian cities. However, no clinical or epidemiological studies data have been published for that city so far. To partially clarify these questions, we carried out a study on this subject on patients who sought the mycology services of Hospital of Federal University of Santa Catarina, from January 1995 to November 1996. The most prevalent dermatophyte was Trichophyton rubrum (58.6%), followed by T. mentagrophytes (25.3%), Epidermophyton floccosum (7.2%), Microsporum canis (4.8%), T. tonsurans T. violaceum (1.6%) and M. gypseum (0.8%). The prevalence of T. mentagrophytes was significantly higher for females than for males, with a frequency of 37.3% and 16.0% respectively, which could be explained by higher infection of T. mentagrophytes in feet and nails, which were percentually more affected in females than in males. These results suggest that, in general, the clinical and epidemiological characteristics of dermatophytoses of our study have similar patterns of those occurring in other southern and southeastern Brazilian cities.

Tinea capitis in California children: a population-based study of a growing epidemic

OBJECTIVE

To describe trends in tinea capitis incidence among California children and to determine subpopulations at increased risk.

DESIGN

Retrospective population-based study.

SETTING

California, 1984 through 1993.

POPULATION

Children < 10 years of age enrolled in Medi-Cal.

OUTCOME MEASURES

California Medi-Cal provider data for first-time prescriptions of oral griseofulvin suspension were used to estimate annual incidence of tinea capitis and calculate risk ratios.

RESULTS

From 1984 through 1993, the incident rate for prescriptions of oral griseofulvin suspension increased by 84.2% for all children, 140.4% for white children, and 209.7% for African-American children. In 1993, incidence rates (per 10,000 enrolled) were 252.1 claimants for African-American children, 23.1 for white, 17.5 for Hispanic, and 14.3 for Asian/Pacific Islander. The highest rate by location was San Francisco County (172.2). In age groups < 5 years and 5 to 9 years, African-American children were 13.1 and 17.6 times more likely to be prescribed griseofulvin than Hispanic children. Since 1987, incidence rates for children 5 to 9 years of age were higher compared with children ages < 5 years.

CONCLUSIONS

Tinea capitis is epidemic among California children with higher rates in the northern counties studied. African-American children are the most affected by this epidemic; however, white children have also experienced increased rates.

Fungi responsible for skin mycoses in Turin (Italy)

There has been a recent increase in the frequency of skin mycoses, coupled with changes in the epidemiology and distribution of the species responsible. Periodic epidemiological analyses of these disease are thus required to ensure their efficacious control. Hair fragments, skin scrapings, specimens from vesicles and blisters and nail parings were seeded on Petri dishes loaded with Sabouraud or Mycosel agar, supplemented with chloramphenicol and with chloramphenicol plus cycloheximide respectively. Parts of each specimen were also mounted in 10% potassium hydroxide for examination under the microscope. Yeasts prevailed over dermatophytes. Microsporum canis was the most frequent dermatophyte, followed by Trichophyton rubrum, T. mentagrophytes and Epidermophyton floccosum. Tinea corporis was the most common mycosis, followed by tinea unguis, tinea capitis and tinea pedis. Men were chiefly bearers of tinea cruris and tinea pedis, women of tinea corporis, and children and teenagers of tinea capitis. Some examples of the transmission of infection through interhuman contact, via animals and from the soil are also presented.

International summit on cutaneous antifungal therapy, focus on tinea capitis, Boston, Massachusetts, November 11-13, 1994

This article reports the highlights of presentations made at an international symposium held on November 11-13, 1994, in Boston, Massachusetts, on the subject of cutaneous antifungal therapy. Some of the key points pertaining to the epidemiology, etiology, pathogenesis, presentation, and management of tinea capitis are discussed.

The dermatophytes

The etiologic agents of the dermatophytoses (ringworm) are classified in three anamorphic (asexual or imperfect) genera, Epidermophyton, Microsporum, and Trichophyton. Species capable of reproducing sexually belong in the teleomorphic genus, Arthroderma, of the Ascomycota. On the basis of primary habitat association, they may be grouped as geophilic (soil associated), zoophilic, and anthropophilic. Adaptation to growth on humans by most geophilic species resulted in diminished loss of sporulation, sexuality, and other soil-associated characteristics. The dermatophytes have the ability to invade keratinized tissue (skin, hair, and nails) but are usually restricted to the nonliving cornified layer of the epidermis because of their inability to penetrate viable tissue of an immunocompetent host. However, invasion does elicit a host response ranging from mild to severe. Acid proteinases, elastase, keratinases, and other proteinases reportedly act as virulence factors. The development of cell-mediated immunity correlated with delayed hypersensitivity and an inflammatory response is associated with clinical cure, whereas the lack of or a defective cell-mediated immunity predisposes the host to chronic or recurrent dermatophyte infection. Chronic dermatophytosis is mostly caused by Trichophyton rubrum, and there is some evidence that mannan produced by this fungus suppresses or diminishes the inflammatory response. Since dermatophytes cause a communicable disease, modes of transmission and control are discussed as well as a survey of recent trends in therapy. Collection of specimens, culture media, and tests for identification are also presented. Genetic studies have led to an understanding of incompatibility mechanisms, pleomorphism and variation, resistance to griseofulvin, and virulence. Molecular biology has contributed to our knowledge of the taxonomy and phylogenetic relationships of dermatophytes.

Dermatophytosis in northern Greece during the decade 1981-1990

Dermatophytic infections are very common in Greece. In the Mycological Laboratory of the Venereal and Skin Diseases Hospital in Thessaloniki, 6572 isolates of different dermatophytes were obtained from 17,120 patients examined. It is suggested that 5% of the people who present with skin problems in Greece suffer from dermatophyte infections. They are frequent causative agents of tinea pedis, tinea cruris, tinea corporis, tinea capitis and tinea unguium. In this paper, the species, the number and the prevalence of the dermatophytes were studied according to location and sex of the patients. The contribution of dermatophyte infections to the overall incidence of superficial fungal infection over 10 years was also studied.

Tinea capitis: new perspectives on an old disease

Tinea capitis caused by Trichophyton tonsurans is a common infection in children, and has become a significant public health problem in the United States. Epidemics of tinea capitis occur both in families and in institutions such as schools and day care centers. Infection is often difficult to eradicate. Fomites and asymptomatic carriers likely contribute to the spread of the disease and to re-infection of treated patients. The morphology of tinea capitis is diverse, from seborrhea-like scaling to tender, inflammed nodules on the scalp. Because a lengthy course of systemic griseofulvin is required to treat this infection, management of tinea capitis can be challenging. As newer antifungal agents are developed, more effective and convenient therapy for tinea capitis may become available.

Frequency of Trichophyton rubrum in tinea capitis

Trichophyton rubrum has led to unprecedented worldwide suppression of other dermatophytes which had been predominant earlier as a causative agent of superficial dermatomycoses. In tinea capitis on the other hand, several other species of Trichophyton or Microsporum are dominant depending on the region or continent. Tinea capitis caused by T. rubrum is a rare event worldwide. Occasional concentrations may be explained by several cases occurring by chance in one family or community. The relative frequency of this causative agent in tinea capitis in children is under 1%. In adults, however, where tinea capitis occurs very infrequently indeed, the incidence of T. rubrum appears to exceed 10%. Apart from two studies from India, one from Iran, two from Portugal and observations from Germany, which in the first country report of around 30% of all cases published, while the others document some 10% each, there are not only any conspicuous, unequivocal concentrations at all. Increased frequency of T. rubrum in this clinical picture has not been easily recognizable over the last decades due to low absolute case numbers.

Ecology and epidemiology of dermatophyte infections

Our knowledge of ecology and epidemiology of dermatophytes and the factors influencing their transmission has helped us understand better the natural history of dermatophytoses. It seems that the anthropophilic agents of scalp infection are being eradicated in developing nations. The exception is Trichophyton tonsurans-related tinea capitis in North America. Microsporum canis is a prevalent agent of tinea capitis in many regions of the world, and this could be related to close association of humans with their pets. Trichophyton violaceum is endemic in certain parts of Eastern Europe, Africa, Asia, and South America but not in North America. Trichophyton rubrum is the most common cause worldwide of tinea pedis, nail infection, tinea cruris, and tinea corporis. Although the incidence of tinea capitis is declining in developed nations, tinea pedis and onychomycosis are becoming more common. The increased use of athletic shoes both by men and women and communal bathing could be contributing factors. Five or six species account for most dermatophytoses globally.

Dermatophytes and dermatophytoses in the Milan area between 1970 and 1989

Between 1970 and 1989 we examined 13,019 patients with dermatophytoses in the Milan area, Northern Italy. The results obtained during the 1980-89 period were compared with those obtained in the years 1970-79. From the data collected, tinea corporis emerged as the most frequently observed dermatophytosis, followed by tinea pedis and unguium. As far as dermatophytes are concerned, the dermatological pattern is dominated by Microsporum canis and Trichophyton rubrum. Other species, such as Epidermophyton floccosum, T. mentagrophytes, M. gypseum, T. violaceum, T. verrucosum, T. tonsurans and T. schoenleinii, have progressively become less evident. Other mycetes, such as T. megninii, T. soudanense, M. langeroni, T. vanbreuseghemii, M. ferrugineum, sporadically isolated in the 1970-79 period, have disappeared in recent years. An analysis of the distribution and frequency of the dermatophytes according to the cutaneous area affected is reported.

Dermatophytosis due to Trichophyton rubrum in northern Greece during the decade 1981-1990

During the years 1981-1990 Trichophyton rubrum was the most frequent causative agent of dermatophytic infections in Northern Greece, especially in cases of tinea pedis, cruris, corporis, and unguium, as well as dermatophytosis of the hands. Between sexes there was a prevalence in women in tinea pedis and toenail infections. Men were particularly infected in the groin, the hands and the face. The chronic follicular dermatophytosis in the lower legs was also presented in women, but tinea corporis and fingernail infections showed no significant differences between the sexes. Also studied were the age of the patients, the inflammatory component of the lesions and the morphotypes of T. rubrum isolated.

Forty four years of dermatophytes in a Chicago clinic (1944-1988)

Data are presented on 39,270 cultures taken over a 44 year span (1944-1988) at the University of Chicago's Dermatology Clinic. In the mid 1940's Microsporum audouinii accounted for 60-80% of isolates. It gradually decreased over the next two decades and disappeared altogether in the 1970's. Trichophyton rubrum, rare in the 1940's accounted for over 60% of isolates in the mid-1960's only to be overtaken by T. tonsurans. This species, not isolated till the mid 1950's, became and remains the dominant dermatophyte at the present time. Both T. mentagrophytes and Epidermophyton floccosum increased in the 1970's and decreased later. Unusual circumstances resulted in clusters of T. verrucosum, T. terrestre, and T. schoenleinii isolates. Infections were associated with rural dairy workers, zoo handlers and immigrant families respectively. M. canis and M. gypseum were steady at a low rate throughout the entire period. Rare isolates included M. cookei, M. persicolor, M. racemosum, T. simii, T. soudanense, T. violaceum, and the soil keratinophile, Aphanoascus fulvescens.

A survey of dermatophytes from human patients in the United States from 1985 to 1987

A survey of dermatophytes isolated from patients seeking medical advice was made from 1985 to 1987 in the United States. The survey included 54 locations with data from 45 cities and one state. Listing of the isolated dermatophytes and the frequency given by percentage of the total follows: Trichophyton rubrum 54.8%, T. tonsurans 31.3%, T. mentagrophytes 6.0%, Microsporum canis 4.0%, Epidermophyton floccosum 2.0%, M. gypseum 0.6%, and T. verrucosum 0.2%. Out of a total of 14,696 isolates M. audouinii was cultured 13 times, T. violaceum 12 times, M. nanum 6 times, T. terrestre 4 times, and T. soudanense twice. Single isolations were made of M. fulvum, M. ferrugineum and T. schoenleinii. Collection of dermatophyte data in Tucson, Arizona, began in 1966. In 1987, the first case of tinea capitis caused by T. tonsurans was observed. Other isolates of this organism as the cause of tinea capitis were made in this city during that year. These infections were in black children. With the recent growth of Tucson, the percentage of blacks in the population increased and this pathogen was introduced into the general population.

Differentiation between Trichophyton mentagrophytes and T. rubrum by sorbitol assimilation

Trichophyton rubrum was easily differentiated from T. mentagrophytes by its ability to assimilate sorbitol with an API 20C AUX strip. One hundred percent of 36 T. rubrum strains and none of 147 T. mentagrophytes strains assimilated sorbitol.