Tinea capitis is one type of superficial fungal infection which is found all over the world. The major etiologic agent of tinea capitis varies in different areas. Tinea capitis in China has unique characteristics. The epidemiology, transmission and therapy of child and adult tinea capitis in China are reviewed in this paper.
Phaeohyphomycosis is a mycotic disease caused by dematiaceous fungi that produce brown yeast-like cells, pseudohyphae, and irregular true hyphae in tissues. Seven Korean cases of subcutaneous phaeohyphomycosis have been reported to date, four males and three females, ranging in age from 9-84 years (mean 50.4 years). Causative organisms of subcutaneous phaeohyphomycosis were 3 of Exophiala jeanselmei, 2 of E. dermatitidis, 1 of Drechslera dematioidea and 1 of Phoma sp. Four cases of abscess and 3 cases of verrucous plaque were present as skin lesions, and were all exposed areas of the body. Patients were treated with itraconazole, ketoconazole, fluconazole or amphotericin B.
The warm tropical climate of the Philippines and its interaction with cultural practices, occupation and immune responsiveness contribute to the increased susceptibility of Filipinos to fungal infections. An investigation to determine the prevalence of fungal infections in dermatology training institutions over a 4-year period was conducted. The results showed that fungal infections rank as the second leading cause of consultation with a prevalence of 12.98%. Pityriasis versicolor (25.34%), tinea corporis (22.63%), tinea cruris (16.7%) and tinea pedis (16.38%) were the most frequently encountered cases. Fungal culture yield is low and Candida sp. is the most common isolate, obtained predominantly from specimens taken from the oral mucosa and nails. Candidiasis is still the most common opportunistic infection followed by coccidioidomycosis, cryptococcosis and aspergillosis. Imidazoles are the most commonly prescribed systemic and topical treatment by Filipino dermatologists. Initial data collected would serve as reference for future research and may be used to compare with epidemiologic data obtained from other Asian countries.
Cutaneous fungal infections are common in Singapore. The National Skin Centre is a tertiary referral centre for dermatological diseases in the country, and sees more than 2, 500 cases of superficial fungal infections annually. Aim: This study analyses data collated from the centre's medical record office as well as fungal culture results from the mycology laboratory. Results: From 1999 to 2003, there were a total of 12, 903 cases of superficial fungal infections seen at the centre. The majority of patients (n=9335) (72.3%) were males. The most common infection was tinea pedis (n=3516) (27.3%), followed by pityriasis versicolor (n=3249) (25.2%) and tinea cruris (n=1745) (13.5%). Candidal infections were also common (n=1430), the majority of which were cases of candidal intertrigo. There were very few cases of tinea capitis, which is uncommon in Singapore. The number of cases of onychomycosis has shown a rising trend over the past 5 years. Trichophyton rubrum was the most prevalent fungal pathogen isolated from all cases of superficial fungal infections of the skin, except for tinea pedis, where Trichophyton interdigitale was the most frequently isolated organism. Dermatophytes remain the most commonly isolated fungal pathogens isolated in toenail onychomycosis, whilst Candida species accounted for the majority of isolates in fingernail onychomycosis. Conclusion: Current epidemiologic trends of superficial fungal infections in Singapore show some similarities to recent studies from the United Kingdom and United States.
Scytalidium dimidiatum is the leading cause of fungal foot diseases in Thailand, in contrast to similar studies in which dermatophytes have been identified as the predominant pathogens. By contrast, the prevalence of Candida albicans in our study was only 2.6-3.0%. Scytalidium fungal foot infection is clinically indistinguishable from that caused by dermatophytes and should be included as a possible cause of treatment failure in tinea pedis and onychomycosis. Without proper culture identification, clinically diagnosed patients would be treated with a standard antifungal regimen leading to minimal response and be interpreted as drug resistant cases resulting in switching of drugs and more aggressive management procedures. Tinea capitis is another health problem in young children. However, for Microsporum canis and some ectothrix organisms, the effectiveness of treatment may be less than endothrix infection. Griseofulvin is still the mainstay antifungal although itraconazole and terbinafine are as effective. Pulse regimen may be another option with advantages of increased compliance and convenience. Two pulses of terbinafine may be sufficient for treating most cases of Microsporum infection, although additional treatment may be needed if clinical improvement is not evident at week 8 after initiating therapy. Chromoblastomycosis is another subcutaneous infection that requires long treatment duration with costly antifungal drugs. The most common pathogen in Thailand is Fonsecaea pedrosoi. Preliminary study of pulse itraconazole 400mg/d 1 week monthly for 9-12 consecutive months showed promising results. The prevalence of Penicillium marneffei infection is alarming in HIV infected patients living in endemic areas. Diagnosis relies on direct examination of the specimens and confirmation by culture. Treatment regimens include systemic amphotericin B or itraconazole followed by long-term prophylaxis. Treatment outcome depends on the immune status of the patient.
Stachybotrys chartarum is a dematiaceous fungus that is ubiquitous in our living environment. This fungus has long been regarded as non-pathogenic and its inhalation effect on humans has been scarcely studied. Recently, however, epidemiologic studies on acute idiopathic pulmonary hemorrhage in infants suggested that the fungus might be potentially pathogenic to humans. To determine the pathogenicity of this fungus, its interaction with the host defense system was studied using polymorphonuclear leukocytes (PMNs) and macrophages. Histopathological analysis of mice intratracheally injected with this fungus was also performed. The results disclosed that the conidia of S. chartarum were resistant to the antifungal activities of alveolar macrophages in terms of phagocytosis, killing and inhibition of germination. However, the conidia could not survive in the lungs of mice when injected intratracheally. Lavage fluid of mycelia that contained the dark slimy material coating the surface of conidia showed cytotoxic activity against macrophages and PMNs. Intratracheal injection of conidia in mice resulted in intraalveolar infiltration of PMNs. When using multiple injections during a 3-week period, strong eosinophilic infiltration into the proximal alveoli and perivascular tissues was observed. Our results suggest that inhalation of conidia may cause serious damage to the human lung, particularly when repeated.
To evaluate a newly developed identification kit, the RID Zyme CAS test for Candida albicans, 1136 C. albicans and 403 non-albicans Candida strains were tested. Distinction of medically important non-albicans strains, with the exception of C. dubliniensis, was obtained. These results show that this new kit is simple and effective for the identification of C. albicans in clinical samples. Furthermore, the one hour period for identification makes it very attractive.
Trichophytia profunda acuta of the glabrous skin (TPAGS) arose in a 67-year-old Japanese man. The patient presented indurated erythematous plaques and nodules on his left forearm. Direct microscopic examination of the scale in KOH preparation was negative for fungal elements, and culture for dermatophytes was also negative. Although fungal infection could not be proven in hematoxillin-eosin stained sections, deep-cut sections of the biopsied skin lesion with PAS stain revealed the ectothrix presence of fungal elements. Nested PCR was done with Trichophyton specific primers directed to internal transcribed spacer gene 1 (ITS1), using template DNA obtained from formalin fixed, paraffin embedded skin sections. A single band corresponding to T. rubrum was obtained, and the etiological agent was thus identified. KOH tests and cultures may often turn out unsuccessful, perhaps reflecting the hair follicle dominant fungus growth in TPAGS. Although these tests are most important for diagnosis of TPAGS, nested PCR using paraffin embedded skin sections may be an alternative method to identify the etiological agent.
The internal transcribed spacer (ITS) region including 5.8S rDNA sequences of 58 isolates of Candida parapsilosis in Brazil and Japan was analyzed. Although most of the C. parapsilosis strains tested were confirmed to belong to three already reported genetically distinct groups (I, II and III) based on their ITS region sequences, 5 strains of the Brazilian isolates showed different sequences from those heretofore reported and suggested a presence of new genotype. For these strains of C. parapsilosis, we proposed a new genetic group (IV). The sequence similarities of this new group of IV to I, II and III were 87.4%, 94.7% and 87.3% in the ITS1 region, respectively. Genetic diversity in ITS regions of the remaining C. parapsilosis strains in Brazil and Japan was also discussed.