A case of Tinea Faciei caused by Trichophyton benhamiae: first report in China

First record of Trichophyton benhamiae isolated from domestic cats in Russia

We report a first case of Trichophyton benhamiae isolation from domestic cats in Russia. Genetically affiliated to European strains T. benhamiae were deposited in NCBI. T. benhamiae strains formed zonal cream-colored colonies, with reversum pigmentation ranging from intensive yellow to orange-brown in one and orange-brown to chocolate in the second strain. Mycelium is colorless, hyphae are septated, rapidly aging with the formation of arthrospores and microconidia. The formation of macroconidia was recorded after 48 hours. A favorable outcome of treatment was recorded after two weeks.

Case Report and Literature Review of Impetigo-Like Tinea Faciei

Impetigo, commonly caused by bacteria, is characterized by lesions of pustules, bullae or golden yellow crusts; it is seldom caused by fungi. Here, we report one case of a 17-year-old female patient with a 1-month history of erythematous pustules on her left cheek. She was clinically diagnosed with “impetigo”, but did not respond to 1 week of treatment with topical mupirocin cream (antibacterial agent). We then saw that a fungal colony grew on the culture, which was identified as T. mentagrophytes based on the morphological and molecular characteristics. The patient was then diagnosed with tinea faciei and was topically treated with 0.2% ketoconazole cream twice per day for 7 days. Through a literature review, we found another 18 cases of impetigo-like tinea faciei with similar clinical manifestations and pathogenic characteristics. Among these, the most common causative agent was T. mentagrophytes complex, which frequently occurs in children and adolescents and exhibits no gender preferences. Systemic and topical antifungals such as terbinafine or itraconazole are effective for impetigo-like tinea faciei caused by T. mentagrophytes complex. However, prolonged course of impetigo in more than 50% cases highlights the importance of mycological examination when dealing with apparent antibiotic-resistant impetigo cases in clinical settings.

Familial Cases of Trichophyton benhamiae Infection Transmitted from a Guinea Pig in Iran

Trichophyton benhamiae is a zoophilic dermatophyte mainly transmitted to humans from guinea pigs. This zoophilic species can also cause dermatophytosis as reported by human contact with other animals, such as rabbit, cat, and fox. Here, we report the tinea faciei and tinea corporis cases: a 12-year-old girl and her 53-year-old father, with no history of immunodeficiency and underlying disease, caused by T. benhamiae transmitted from a guinea pig in Iran. Dermatological examination revealed several erythematous, round, scaly, and approximately 1-4-cm-diameter lesions in both patients. The girl had seven skin lesions, and her father presented two skin lesions on the front side of his neck. The girl's lesions had started 3 weeks before and her father's lesions appeared 7 days after the first clinical appearance of the lesions in the daughter. The girl had daily close contact with a guinea pig, while her father did not have any direct exposure to the pet. Examination of the lesions scraping with 10% potassium hydroxide (KOH 10%) revealed hyaline septate hyphae and arthroconidia. The dermatophyte isolated in culture was identified as T. benhamiae using molecular analysis. The patients were successfully treated using topical sertaconazole nitrate 2% cream twice a day for 4 weeks.

Updates on Genital Dermatophytosis

Dermatophytes are a group of keratinophilic fungi, which normally cause superficial infection of skin, hair and nails. Based on ecology, they are classified into three groups: anthropophilic, zoophilic and geophilic. Superficial dermatophytic infection of the genital region is called genital dermatophytosis, tinea genitalis or pubo-genital dermatophytosis. In this review, we would like to discuss briefly, the various clinical presentations of genital dermatophytosis, current changes in the taxonomy and nomenclature, introduction of new diagnostic techniques and briefly describe some common dermatophytes and their sources. Also, there are serious concerns associated with the recent development of antifungal resistance among the dermatophytes. We are also facing the scenario of hard-to-treat dermatophytosis.