The role of ingrown hairs in persistent kerion of children: A clinical study.

Tinea capitis, a common public health problem in developing countries, has severe forms such as kerion. However, the underlying mechanisms and standard treatments for persistent cases of tinea capitis or kerion remain controversial. In this work, we investigate the ingrown hairs and corresponding treatment in persistent kerion of children. Children with persistent kerion were enrolled among 312 cases of tinea capitis at the Department of Dermatology, Hangzhou Third People's Hospital from January 2020 to June 2024. The presence of fungal infection was ascertained by direct microscopic examination under calcofluor white staining and routine culture. The structure of the ingrown hairs was observed directly by a dermatoscope, which was subsequently extracted using sterile tools. A total of six cases of persistent kerion among 312 cases of tinea capitis were enrolled. Ingrown hairs were ascertained under dermatoscopy and extracted by minor operation. Except for one patient who continued oral terbinafine, the other five cases were cured by removal alone. Ingrown hairs, induced by fungal infection, may be an aggravating factor of persistent course of tinea capitis. Our study demonstrated that the presence of ingrown hairs could be confirmed through direct dermatoscopy, and patients experienced significant improvement following removal treatment under dermatoscopy.