Unusual cases of paediatric tinea faciei transmitted by guinea pigs

A survey of 701 cases of tinea faciei in Hangzhou, southeastern China, from 2018 to 2023

BACKGROUND

Tinea faciei, a specific dermatophytosis that affects the glabrous skin of the face, not only causes physical discomfort but also leads to greater psychological distress. Tinea faciei is a public health concern.

OBJECTIVES

To analyse the epidemiological characteristics, responsible dermatophyte species and clinical features of tinea faciei in Hangzhou.

METHODS

Data were obtained from the Laboratory Information System of the Mycology Laboratory and Medical Information System at a hospital in Hangzhou. Isolates were identified based on their macroscopic appearance and microscopic morphology.

RESULTS

Tinea faciei was diagnosed in 701 patients, involving 359 males and 342 females, aged between 2 months and 97 years. In total, 499 isolates (71.18%) were identified as Trichophyton rubrum. Anthropophilic isolates were identified in 297 (82.73%) males and 207 (60.53%) females (p < .01). Among patients with anthropophilic dermatophytes infection, 447 (88.69%) were adults. Zoophilic dermatophytes were isolated in 57 (15.88%) males and 130 (38.01%) females (p < .01), among whom 108 (57.75%) were children.

CONCLUSIONS

Anthropophilic dermatophytes, especially T. rubrum, were the predominant cause of tinea faciei, while zoophilic dermatophytes were the most prevalent in children. Compared with men, women may be more susceptible to zoophilic dermatophytes.

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.

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

Background

Trichophyton benhamiae is a zoophilic dermatophyte that can cause tinea in humans and animals. Lesions caused by T. benhamiae tend to be highly inflammatory, and patients are often infected by animals or other patients infected with T. benhamiae. In this paper, we report the first case of tinea faciei caused by T. benhamiae in a Chinese girl who might be transmitted from a fox.

Case presentation

A 4-year-old girl from HaiNing city developed an itchy, erythematous, and annular plaque on her right face for the past 2 months. Before the lesion appeared, she was in close contact with the fur of a fox for almost 1 week. Septate hyaline hyphae were detected by direct mycological examination of the scales. Cultures grew on Sabouraud’s dextrose agar (SDA) at 26 °C for 2 weeks revealed the presence of T. mentagrophytes. A molecular sequencing test confirmed that the isolate was consistent with reference strains to T. benhamiae. Then, the diagnosis of tinea faciei due to T. benhamiae was made. Treatment with terbinafine (oral 125 mg/d) and sertaconazole nitrate cream (topical, twice daily) for 4 weeks was initiated and achieved significant improvement of the skin lesions.

Conclusions

This rare dermatophytosis case highlights the importance of ITS sequencing in helping to recognize rare pathogenic fungi that can be easily misdiagnosed with a conventional morphological diagnosis.