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The causative dermatophytic species of tinea capitis were identified in 91 patients in Qatar. Microsporum canis was the most common isolated organism (86.81%) followed by Microsporum ferrugineum and Trichophyton violaceum. A gray patch type of tinea capitis was the predominant presentation (87.91%), and the disease was more prevalent among Qatari boys.
BACKGROUND: Inflammatory tinea capitis or kerion is the result of a hypersensitivity reaction to a dermatophytic infection. Majocchi's granuloma, in contrast, usually begins as a suppurative folliculitis and culminates in a granulomatous reaction. OBJECTIVES: To present clinical, mycological and histopathological findings for 19 cases of kerion of the scalp in children. METHODS: Nineteen children were investigated (14 boys and five girls) with a mean age of 6.5 years. A potassium hydroxide (KOH) exam and culture in Sabouraud dextrose agar were performed, followed by a biopsy with hematoxylin and eosin, periodic acid-schiff (PAS) and Gomori-Grocott stains. The same investigations were carried out in four control cases of noninflammatory tinea capitis. RESULTS: Clinical history varied from 2 to 16 weeks (mean 6.6 weeks). Diagnosis was confirmed by a positive KOH exam: all cases except one had a positive culture. The following dermatophytes were isolated: Microsporum canis (32%), Trichophyton mentagrophytes (27%), Trichophyton tonsurans (21%), Trichophyton rubrum (10%) and Microsporum gypseum (5%). The histopathological findings were: suppurative folliculitis (SF) 11%, SF plus suppurative dermatitis 37%, suppurative and granulomatous dermatitis (SGD) 26% and SGD plus fibrosing dermatitis 26%. Fungi were observed in 63% of the histopathological sections. Perifollicular infiltrates (PF) around the parasitized hair follicles were identified in the four noninflammatory control cases due to M. canis. CONCLUSIONS: Kerion Celsi is an inflammatory or suppurative type of tinea capitis caused by zoophylic dermatophytes (M. canis and T. mentagrophytes), but also by antrophophylic (T. tonsurans and T. rubrum) and geophylic (M. gypseum) dermatophytes. Histopathological findings showed a spectrum from mild suppurative folliculitis to dense granulomatous infiltrates without a clear relationship with the clinical features.
Between 1985 and 1993, 13,880 patients were studied for possible forms of dermatophytoses. The most frequently isolated dermatophyte was in 2821 positive cases Microsporum canis (50%), followed by Trichophyton rubrum (27%), Trichophyton mentagrophytes (10.6%), Epidermophyton floccosum (9.3%), Microsporum gypseum (2.3%), Trichophyton violaceum (0.6%), Trichophyton tonsurans (0.2%) and Trichophyton verrucosum (< 0.1%). The genera and species isolated were also considered in relation to the site of the lesion. Our epidemiological data were compared with those obtained by other authors in other cities and with those obtained in Rome in previous studies conducted between 1972-77 and 1978-83. Results obtained by various investigators in Europe are also discussed.
Between 1986 and 1995, 4104 children were observed in the Clinic of Dermatology in Cagliari, Italy. Three hundred and thirty-six children (8.2%), 188 boys and 148 girls, aged 1 month to 13 years, were affected by tinea capitis. Microsporum canis was detected in 278 cases (82.7%) and Trichophyton mentagrophytes in 58 cases (17.3%). Systemic treatment with 20-25 mg kg-1 day-1 griseofulvin led to complete recovery in 30-40 days. None of the patients relapsed. The epidemiology of the infection was analysed according to age, sex and seasonal progression. Microsporum canis was the preponderant aetiological agent of tinea capitis in children in the district of Cagliari, Italy.
During a 3-year period (1999-2001) a total of 94 cases of dermatophytosis were seen in patients from 0 to 18 years of age attending the Department of Dermatology, Venerology and Allergology of Gdańsk Medical University. Mycoses were diagnosed on the basis of clinical picture and direct microscopy and were confirmed by positive cultures. The most frequent pathogens were Microsporum canis (62%) and Trichophyton rubrum (12%). The most often forms of dermatophytosis in children were tinea cutis glabrae (42%) and tinea capitis (30%). Microsporum canis predominated in both locations. Glabrous skin lesions were the most frequent in children aged 8-15 years; the peak of scalp lesions was observed mainly in children aged 4-7 years. Tinea pedis occurred more frequently than suspected. Tinea pedis was observed mainly in adolescents (above the age of 12 years)--the majority of cases were caused by T. rubrum and T. mentagrophytes var. granulosum. Onychomycosis was highly uncommon, caused mainly by T. rubrum. Dermatomycoses in general were most frequent in October and November.
Tinea incognito or steroid modified tinea is a dermatophytic infection in which topical or systemic steroids, administered as a result of dermatological misdiagnosis or preexisting pathologies, have modified the clinical appearance of the fungal infection, transforming the typical ringworm and mimicking other skin diseases. This is a retrospective study of the agents, clinical aspects, sources of infection of 200 cases (98 males, 102 females, mean age 42 years) of tinea incognito, observed in Siena and Milan, Italy, in the period 1987-2002. In order of decreasing frequency, Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton violaceum and Trichophyton erinacei were isolated. The clinical appearance of the infection was lupus erythematosus discoid-like, eczema-like, rosacea-like, especially on the face, impetigo-like and eczema-like on trunk and limbs. Less often the dermatophytosis resembled psoriasis, purpura, seborrhoic dermatitis and lichen planus. There was folliculitis in 9% of cases and dermatophytid in 3% of cases. Antimycotic therapy brought about clinical and mycological recovery in all patients except one, who had iatrogenic immunodepression.
A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5-1.0 microm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis, and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.
A normally asporogenous pleomorphic strain of Microsporum gypseum was induced to sporulate by controlled aeration and dehydration. Aeration of the pleomorphic strain under optimal cultivation conditions caused the initiation of a sporulation cycle with equivalent growth parameters and percentage intracellular water loss as the wild-type strain. Initiation of sporulation was not due to alteration of the medium's nutrient concentration or consistency, concentration of fungal growth by-products, or removal of volatile "staling factors." Macroconidia formed by the pleomorphic colonies were of characteristic wildtype morphology, but germinated to form typical pleomorphic colonies, indicating that the induced sporulation was strictly phenotypic and reversible. Other asporogenous pleomorphic strains from different dermatophyte genera also were induced to form macroconidia by aeration, suggesting a similarity in sporulation induction in Microsporum sp., Epidermophyton floccosum, and Trichophyton violaceum. Initiation of sporulation by aeration further suggested that the pleomorphic mutation was one which affected the sensitivity of the pleomorphic aerial hyphae to natural sporulation inducers (i.e., decreased humidity) and did not represent a loss in the ability to form fertile macroconidia.
By using ethylene glycol extraction of whole submerged cultures followed by Sephadex G-200 and diethylaminoethyl-Sephadex chromatography, we isolated four distinct glycopeptides from Trichophyton mentagrophytes, T. rubrum, and Microsporum canis. Chemical analyses revealed that these glycopeptides contained mostly carbohydrate (42.5 to 81.6%) and protein (4.3 to 11.3%), with lesser amounts of phosphorus (0.4 to 6.0%) and hexosamines (0.3 to 0.6%). Based upon total carbohydrate and monosaccharide content, these dermatophyte glycopeptides could be divided into two chemical groups: glucopeptides (DSI1) and mannopeptides (DSI2, DSII1, and DSII2). The mannopeptides and glucopeptides of each species of dermatophyte were not significantly different chemically from those derived from the other two dermatophyte species studied. Skin testing of DSI1-glycopeptides or DSI2-mannopeptides in immunized guinea pigs indicated that only the DSI2-mannopeptides elicited a delayed hypersensitivity reaction. Skin testing T. mentagrophytes 62-infected guinea pigs with the four purified DS-glycopeptides, as well as earlier fractions from the purification scheme, derived from T. mentagrophytes, T. rubrum, and M. canis, again indicated that only the DSI2-mannopeptides of the two Trichophyton species elicited a delayed hypersensitivity reaction. The number of infections or duration of infection had no effect on the size of the skin test response. DSI2-mannopeptides were non-cross-reactive between genera when tested in Trichophyton-immunized or -infected guinea pigs and Microsporum-immunized guinea pigs.
The mutual phylogenetic relationships of dermatophytes of the genera Trichophyton, Microsporum, and Epidermophyton were demonstrated by using internal transcribed spacer 1 (ITS1) region ribosomal DNA sequences. Trichophyton spp. and Microsporum spp. form a cluster in the phylogenetic tree with Epidermophyton floccosum as an outgroup, and within this cluster, all Trichophyton spp. except Trichophyton terrestre form a nested cluster (100% bootstrap support). Members of dermatophytes in the cluster of Trichophyton spp. were classified into three groups with ITS1 homologies, with each of them being a monophyletic cluster (100% bootstrap support). The Arthroderma vanbreuseghemii-Arthroderma simii group consists of A. vanbreuseghemii, A. simii, Trichophyton mentagrophytes isolates from humans, T. mentagrophytes var. quinckeanum, Trichophyton tonsurans, and Trichophyton schoenleinii. Arthroderma benhamiae, T. mentagrophytes var. erinacei, and Trichophyton verrucosum are members of the Arthroderma benhamiae group. Trichophyton rubrum and Trichophyton violaceum form the T. rubrum group. This suggests that these "species" of dermatophytes have been overclassified. The ITS1 sequences of 11 clinical isolates were also determined to identify the species, and all strains were successfully identified by comparison of their base sequences with those in the ITS1 DNA sequence database.
This report describes the application of PCR fingerprinting for the identification of species and varieties of common dermatophytes and related fungi utilizing as a single primer the simple repetitive oligonucleotide (GACA)(4). The primer was able to amplify all the strains, producing species-specific profiles for Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton ajelloi, and Epidermophyton floccosum. Intraspecific variability was not observed for these species. Instead, three different profiles were observed in the Trichophyton mentagrophytes group.
The Sensititre YeastOne antifungal panel was used to test 49 dermatophytes belonging to the species Epidermophyton floccosum, Microsporum gypseum, Microsporum canis, Trichophyton tonsurans, Trichophyton rubrum, and Trichophyton mentagrophytes. The MICs of four antifungals obtained with the Sensititre YeastOne antifungal panel were compared with those obtained by the reference NCCLS microdilution method. The levels of agreement between the two methods (<or=2 dilutions) were 81.6% with amphotericin B, 87.7% with itraconazole, 67.3% with fluconazole, and 69.4% with ketoconazole.
A total of 1,101 patients was studied for the incidence and distribution of dermatophytes in the San Francisco Bay Area from 1974 to 1978. 267 dermatophytes were isolated and identified. Trichophyton rubrum and Trichophyton tonsurans were the most prevalent dermatophytes. T. rubrum caused 83% of tinea pedis, 82% of tinea unguium, 80% of tinea manuum and 66% of tinea cruris. T. tonsurans was the major cause of tinea capitis (60%) followed by Microsporum canis. Microsporum audouinii was not encountered in this survey.
Over a 17 yr period from 1966 to 1982, 4354 dermatophytes were identified at the Australian National Reference Laboratory in Medical Mycology. The most frequently identified species was Trichophyton rubrum, accounting for 35.3% of identifications, followed by Trichophyton mentagrophytes (26.5%), Trichophyton tonsurans (12.8%), Epidermophyton floccosum (10.7%) and Microsporum canis (8.4%). Specimens taken from the feet were the most common source of the Trichophyton rubrum isolates, followed by specimens from the groin. The highest incidence of T. rubrum and other Trichophyton infections was found in males in the age group 21-30 yr. Microsporum species were most commonly isolated from children aged 10 yr or less. In 1.5% of specimens, more than one fungal species was isolated. In most of these instances a yeast (predominantly Candida species) was found in addition to a Trichophyton species.
Statistical analysis was made of a total of 5530 patients (6798 cases) of dermatophytoses presenting at our private clinic during the period 1992 to 2001. The number of patients and cases represents 8.0% and 9.8% of the entire outpatient population during that time, respectively. Sex ratio (male/female) was 1.5. Among the 6798 dermatophytoses cases, tinea pedis was most frequent (65.8%), followed by tinea unguium (20.7%), tinea cruris (7.2%), tinea corporis (3.9%), tinea manuum (2.4%) and tinea barbae (0.04%). The incidence of tinea unguium increased, whereas that of tinea pedis, tinea cruris, and tinea corporis decreased during this ten year period, and 35.8% of dermatophytoses patients had more than two clinical subtypes simultaneously. Three thousand seven hundred ninety-five dermatophytes were isolated during the survey. : Trichophyton rubrum (TR)(79.4%), Trichophyton mentagrophytes (TM)(19.5%), Microsporum canis (MC)(0.7%), Epidermophyton floccosum (EF) (0.3%), and Microsporum gypseum (MG) (0.1%). Compared with our previous analysis reported for the period 1982 to 1991, the frequency of dermatophytoses increased, especially among aged individuals. Of the clinical subtypes, tinea pedis and tinea unguium were higher, but tinea cruris and tinea corporis were lower, and tinea capitis was not seen in the current survey. Among dermatophytes, TR was increased and other types of fungi were decreased. TR was 4.08 times more common than TM; this ratio is higher than our previous report.
A streptomycete was isolated from an Easter Island soil sample and found to inhibit Candida albicans, Microsporum gypseum and Trichophyton granulosum. The antibiotic-producing microorganism was characterized and identified as Streptomyces hygroscopicus. The antifungal principle was extracted with organic solvent from the mycelium, isolated in crystalline form and named rapamycin. Rapamycin is mainly active against Candida albicans; minimum inhibitory concentration against ten strains ranged from 0.02 to 0.2 mug/ml. Its apparent activity against Microsporum gypseum and Trichophyton granulosum is lower because of its instability in culture media on prolonged incubation required by these fungi. No activity was observed against gram-positive and gram-negative bacteria. Acute toxicity in mice is low.
Isolates of Microsporum canis, Microsporum gypseum and Epidermophyton floccosum were observed to produce antibacterial activities under cross-resistance to fusidic acid. The activity from E. floccosum was shown to be due to fusidic acid, diketofusidic acid and 3-ketofusidic acid. Possible contributions of these antibiotics to microbial interaction during dermatophytosis is discussed.
In the last 50 years the spectrum of agents of dermatophytoses changed. The change is remarkable especially in the case of zoophilic dermatophytes. Microsporum canis has displaced Trichophyton verrucosum. In the period from 1966 to 1970 2822 dermatophytoses were registered as occupational dermatoses in the former German Democratic Republic. In the following years the number of these diseases was continuously reduced, between 1981 and 1985 down to 995 cases. This reduction is predominantly the result of active immunoprophylaxis by means of inactivated, hydrolized vaccines, mainly by the Soviet live vaccine LTF-130. The scientific basis of this vaccination was established by Kielstein and co-workers. The treatment of Microsporum canis infection of the scalp requires the administration of systemically acting antimycotics over a long period (6-8 weeks).