[Microsporum canis infection from a cat : A source of tinea capitis and dermatophytosis in an entire family].

Tinea capitis is a common fungal infection of the scalp predominantly affecting children. It is often misdiagnosed due to its clinical resemblance to other dermatological conditions such as psoriasis and seborrheic dermatitis. This case report presents a 4-year-old boy who was initially misdiagnosed and treated for psoriasis but later correctly diagnosed with tinea capitis caused by Microsporum canis. The diagnosis was confirmed through microbiological culture and histopathological examination after local corticosteroid treatments failed to show improvement. Subsequently, it was discovered that the entire family, including the boy's sister, mother, and father, had also developed dermatophytosis due to zoonotic transmission of Microsporum canis from the family cat. The patient and his family were successfully treated with terbinafine, and the family cat was treated by a veterinarian. This case underscores the importance of thorough diagnostic procedures, including consideration of pet and familial exposure, to prevent misdiagnosis, reduce the transmission of tinea capitis to other family members and ensure successful treatment outcomes.