Early Stage Alopecia Areata Is Associated With Inflammation in the Upper Dermis and Damage to the Hair Follicle Infundibulum

The study examined 87 patients with early-stage alopecia areata (AA) and found that there was significant inflammation in the upper dermis and damage to the hair follicle infundibulum. Inflammation was characterized by T-lymphocytic invasion and regression of the lower follicle, with 13% of patients testing positive for anti-nuclear antibody (ANA), more commonly in women (21%) than in men (5%). Eosinophilic infiltration, which was present in 40% of patients, correlated with higher serum IgE levels and more severe perivascular lymphocytic inflammation. Mast cells were also found to be abundant in the upper dermis and correlated with eosinophil presence. The study concluded that the damage to the hair follicle infundibulum might be an important early change in AA, potentially caused by lymphocyte cell infiltration and suggesting that AA may involve damage to the upper hair follicle as well as the bulb, possibly involving hypersensitivity and autoimmunity.