Clinical and Histopathological Features of Itch in Patients with Alopecia Areata

The study investigated the clinical and histopathological features of itch in patients with Alopecia Areata (AA), enrolling 156 patients (92 females and 64 males, aged 4-80 years). It found that 9% (14/156) of these patients experienced itch, which coincided with the early stages of hair loss. Histopathological examination revealed epidermal thinning and lymphocytic infiltration around hair follicles in itchy AA lesions, as well as a high number of mast cells, which are known to release itch-inducing mediators. Additionally, the expression of 5-lipoxygenase (5-LOX), an enzyme involved in producing the itch mediator leukotriene B4, was increased in the epidermis and around hair follicles of patients with AA and itch. The study suggests that the presence of pruritogen-releasing cells (like mast cells and lymphocytes) and enzymes for pruritogen production may be involved in the induction of itch in AA patients. The findings indicate a potential link between the immune response and itch in AA, with the need for further research on both itchy and non-itchy AA scalps.