Tinea faciei in an infant caused by Microsporum gypseum simulating a dry impetigo

Nannizzia species causing dermatophytosis in cats and dogs: First report of Nannizzia incurvata as an etiological agent in Brazil

Dermatophytosis is a superficial cutaneous infection, most commonly caused by fungal species such as Microsporum canis, Nannizzia gypsea (Microsporum gypseum), and Trichophyton mentagrophytes in dogs and cats. The zoonotic potential of these species is concerning, as companion animals are increasingly close to their owners. Therefore, the objectives of the study were to evaluate the current prevalence of Nannizzia-causing canine and feline dermatophytosis in Curitiba and Metropolitan Region, as well as perform phenotypic and phylogenetic characterizations of these isolates. Thus, 241 skin and fur samples from 163 dogs and 78 cats were analyzed from 2020 to 2021. The samples were obtained from animals of three sources: Veterinary Hospital of the Federal University of Paraná, animal shelters, and private clinics. The diagnosis was performed through phenotypic characterization and sequencing ITS rDNA region. Among 97 positive samples for dermatophytes, Nannizzia was identified in 14 (14.4%) samples, while other dermatophyte genera were found in the remaining 83 (85.6%) samples. Among the canine samples, nine (90%) were N. gypsea, and one (10%) was N. incurvata. Whereas in feline samples, three (75%) were N. gypsea, and one (25%) was N. incurvata. It was concluded that among 97 animals infected with dermatophytes, dogs (24.4%; 10/41) were significantly more affected by Nannizzia than cats (7.1%; 4/56) (P < .05). According to molecular analyses, the ITS rDNA region provided satisfactory results for species-level identification of Nannizzia, confirming the first report of N. incurvata as an etiological agent of canine and feline dermatophytosis in Brazil.

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.

Dermatophytosis caused by Microsporum gypseum in infants: report of four cases and review of the literature

Dermatophytosis caused by Microsporum gypseum is rare, especially in infants, with few published cases. Diagnosis in this age group is frequently delayed. We review the literature and report 4 new cases of tinea of glabrous skin caused by M. gypseum mimicking eczema in infants. Considering new and previously reported cases, half of patients were exposed to sand, emphasizing the importance of this transmission vehicle in this age group. In conclusion, although rare, dermatophytosis by M. gypseum should be part of the differential diagnosis of inflammatory dermatosis in infants. A clinical suspicion and the availability of culture are keys to the diagnosis.

Annular, erythematous skin lesions in a neonate

A 7-day-old premature female infant presented with rapidly progressive, erythematous, annular skin lesions from the 5^th day of life. She was diagnosed provisionally as a case of neonatal lupus erythematosus and was investigated accordingly. Histopathological examination of the skin biopsy specimen revealed presence of hyphae of dermatophytes in the stratum corneum, and the diagnosis was changed to tinea corporis. Differential diagnosis of the annular erythema of infancy has been discussed and the importance of scraping a scaly lesion for KOH preparation in the diagnostic work-up of such a patient has been highlighted.

Extensive neonatal dermatophytoses

We report a 25-day-old boy who was referred to our dermatology unit for evaluation of extensive annular erythematous lesions on his body. We initially considered the differential diagnoses of candidiasis and neonatal lupus erythematosus but investigations revealed the case as tinea corporis due to a relatively uncommon causative agent, Microsporum gypseum. To the best of our knowledge it is the first case of extensive neonatal dermatophytoses caused by this organism. The possible causes and the role of steroids in producing the clinical picture in our patient are discussed.

Tinea faciei incognito due to Trichophyton rubrum as a result of autoinoculation from onychomycosis

The localisation of a dermatophytosis on the face is rare. Differential diagnoses include a broad range of dermatological disorders, e. g. contact dermatitis, psoriasis vulgaris, seborrhoeic dermatitis, demodicosis, and polymorphic photo eruptions. Two patients suffering from tinea faciei incognito caused by Trichophyton rubrum are presented. Diagnosis was based on mycological diagnostics of skin scrapings using Calcofluor preparation and cultivation of the causative dermatophyte. Both patients were suffering from tinea pedis and tinea unguium caused by the same dermatophyte species. An infection caused by Trichophyton rubrum of the face always occurs following autoinoculation from a pre-existing tinea pedis and tinea unguium of feet and toenails, sometimes of the fingernails.