Diffuse Alopecia Areata Is Associated With Intense Inflammatory Infiltration and CD8+ T Cells in Hair Loss Regions and an Increase in Serum IgE Level

The study compared 17 patients with diffuse alopecia areata (AA) to 37 with patchy AA and 27 healthy controls, revealing that diffuse AA is characterized by more intense inflammatory infiltration, especially by CD8+ T cells, and higher serum IgE levels. The average age of diffuse AA patients was 27, and their condition often began acutely in spring or summer, frequently following scalp itching. The increased infiltration and IgE levels suggest a hypersensitivity component in diffuse AA's pathogenesis. The presence of eosinophils was also noted as a potential diagnostic marker, although their exact role is unclear. The study's small sample size indicates a need for further research to better understand diffuse AA.