Non-Invasive Techniques for Evaluating Alopecia Areata

Alopecia areata (AA) is a common cause of hair loss, particularly in young patients, and can be assessed using various non-invasive techniques. Key methods include trichoscopy, videodermoscopy, pull test, global scalp photography, and advanced imaging techniques like reflectance confocal microscopy (RCM), multiphoton microscopy (MPM), and high-frequency ultrasonography (HF-USG). Trichoscopy often reveals short vellus hairs and yellow dots, while AA activity is indicated by black dots, micro-exclamation mark hairs, and tapering hairs. RCM provides near-histological resolution for skin evaluation, MPM offers insights into hair follicles and scalp inflammation, and HF-USG helps distinguish hair cycle phases, all contributing to the diagnosis and management of AA.