Which organism is the most important cause of Tinea capitis in school children?

• A. Microsporum audouii
• B. Microsporum canis
• C. Trichophyton rubrum
• D. Trichophyton tonsurans

Answer: (B)

Understanding what drives tinea capitis in school-aged children comes down to transmission routes. Microsporum canis is a zoophilic fungus commonly transmitted from infected pets such as cats and dogs to children. Because kids often have close, frequent contact with pets and share spaces where pets roam, this animal-to-human transmission makes Microsporum canis a leading cause of scalp ringworm in pediatric populations. It can produce a range of scalp lesions from inflammatory kerion to more subtle scaly patches, and it tends to spread readily within households and schools through close contact or shared objects. In contrast, Trichophyton tonsurans spreads mainly from person to person and is also common in school settings, but when the emphasis is on the pet-associated route and its strong association with pediatric cases, Microsporum canis stands out as the best answer. The other fungi listed are less typical etiologies for scalp infections in children in many regions (for example, Trichophyton rubrum more often affects non-scalp sites, and Microsporum audouinii has declined in prevalence).