Differential Diagnosis of Scalp Hair Folliculitis

Scalp hair folliculitis was a common dermatological condition that posed diagnostic and therapeutic challenges due to the absence of precise guidelines. It could be caused by various infectious agents like bacteria, viruses, and fungi, as well as noninfectious factors. Noninfectious diseases such as folliculitis decalvans capillitii and lichen planopilaris could also present as folliculitis. The classification of folliculitis was complex and controversial, with three main groups identified: infectious folliculitis, noninfectious folliculitis, and perifolliculitis. Diagnosis often required histologic confirmation beyond clinical observation. The article provided a summary of the different inflammatory diseases affecting scalp hair follicles, along with their differential diagnoses and histological characteristics.