Microsporum infection: features of the modern clinical course, diagnosis and therapy; Микроспория: особенности современного клинического течения, диагностики и терапии

Introduction. Microsporum canis (M. canis) is a zoophilic dermatophyte, causative agent of human and animal dermatophytosis. Scalp mycosis caused by M. canis, accompanied by involvement of a large area of the skin, rarely develops in adults due to physiological peculiarities caused by low pH and high concentration of polyunsaturated fatty acids in sebum. Epidemiological data on the incidence of mycosis in adults vary from 1.5 to 44% in different countries. Late treatment, diagnostic errors and the use of topical corticosteroids contribute to the dissemination of the process. Due to the widespread increase in the number of adult cases of microsporidia infection, the situation necessitates the need to increase awareness of the medical community. Aim. To analyse the clinical and laboratory features of M. canis infection in an adult patient. Results. This article describes a case of scalp mycosis with diffuse skin lesions caused by M. canis in an adult patient. Effective treatment was delayed for a year due to incorrect clinical and laboratory diagnosis. In Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology» during the laboratory examination ial the growth of M. canis culture was obtained. Direct microscopy revealed the location of spores as an ectothrix. Treatment with systemic itraconazole according to a continuous scheme gave a positive result within six weeks. Conclusion. Scalp mycosis with extensive involvement of the trunk and extremities caused by M. canis is clinically uncommon in adults in most regions, emphasising the difficulty in diagnosing widespread dermatophyte infection in this clinical example. In cases presenting with extensive erythema with scaling on the scalp and trunk, fungal infection should be excluded. Careful collection of epidemiological history including migration, animal contact and physical examination for broken hairs, luminescent diagnosis and mycological investigations are required. © 2025 Elsevier B.V., All rights reserved.