Abstract: Objective To find out incidence and pathogens of kerion in Shanghai in the last 19 years.Methods Retrospective analysis was used. Diagnosis of tinea capitis was confirmed by direct microscopic examination and (or) fungal culture. The identification of fungi was based on the macroscopic and microscopic characteristics of the colonies. Clinical features,hair invasion patterns and pet contact history were recorded for each patient.Results Total 1 009 tinea capitis cases were in the servey. Kerion was seen in 114 cases: 44 males and 70 females. Their age was from 20 days to 68 years old with an average of 10.60 years. Kerion was most often seen in children between 5 and 10 years of age,followed by children younger than 5 years old. Ectothrix (66 cases) was more than endothrix (48 cases) on the patterns of invasion in kerion patients.Ninety-five kerion cases were positive cultured. Microsporum canis (30.53%) was the most common pathogen, followed by, Trichophyton violaceum (22.11%), T. mentagrophytes (20.00%), T. rubrum (15.79%), T. tousurans (7.37%) and M.gypseum (4.21%). Incidence of kerion was rising especially caused by T. mentagrophytes.Conclusions Kerion was common seen in children younger than 10 years old. M. canis was the most common pathogen and ectothrix was the main invasion pattern of kerion in Shanghai.

Key words: tinea capitis, kerion, dermatophytes