404. Tinea Capitis: Are Epidemiologic Shifts Associated With Distinct Clinical Presentations?

BACKGROUND: Tinea capitis is an infection of the hair on the scalp caused by dermatophytic fungi. Geographic distribution of individual organisms has changed significantly over time. In early 20th century Europe, M. audouinii and T. schoenleiniipredominated, both of which are anthropophilic species, being passed from human to human. This was followed by a rise of zoophilic species, those passed from animals to humans, such as M. canis and T. mentagrophytes. The epidemiological and biological underpinnings of these continuous changes over time are complex and the importance of environmental factors, genetic predisposition, and movement of populations has been broadly debated. This study aims to characterise the organisms causing tinea capitis at a pediatric tertiary care center in Minneapolis, Minnesota. METHODS: We retrospectively reviewed the electronic medical record from 2010–2015 and identified 42 children with culture positive tinea capitis. RESULTS: In the 18 (42.9%) patients that were infected with either T. violaceum or T. soudanese, all were of African ethnicity. In contrast, T. tonsurans, which is now the most common cause of tinea capitis in the United States, was identified in a minority of African patients (3.8%). These ethnic differences in infective species were statistically significant (Fischer exact test P-value <0.0001). We also identified inter-species differences in the presence of an inflammatory response as measured by bogginess, pustulation, and lymphadenopathy (P = 0.027). Though anthropophilic species such as T. tonsurans and T. violaceum classically cause less inflammation, we identified differences between these anthropophilic species. Specifically, we found that T. tonsurans was more likely to cause an inflammatory response than T. violaceum (68% vs. 22%). CONCLUSION: Historically, T. violaceum was partially geographically limited to Africa and Asia, while T. soudanese was seen only in Africa. Both T. violaceum and T. soudanese can cause tinea capitis with minimal inflammation, mimicking seborrheic dermatitis, and leading to misdiagnosis and incorrect treatment. Studying epidemiologic changes in tinea capitis can help us understand shifts in the clinical presentation of this disease as our population make-up evolves, allowing us to provide crucial quality health care to all. DISCLOSURES: All authors: No reported disclosures.