Alopecia Areata: Pathogenesis and Clinical Picture

Familial aggregation of alopecia areata

“…[1][2][3][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The previous reports of AA familiarity were often highlighted with a statement concerning the number of patients with affected family members. In our study 21.8% of the patients had a positive family history of AA defined by the affection of at least one first-degree relative.…”

Alopecia areata: an autoimmune disease?

“…The increased association of AA with other autoimmune diseases within the same individual and/or within blood relatives of affected people also provides evidence of inherited autoimmune susceptibility (75)(76)(77). However, some question the belief that AA is found in increased association with particular disease such as thyroiditis and vitiligo (78,79).…”

Comparison of Alopecia areata in Human and Nonhuman Mammalian Species

“…The poor prognosis of patients with AA and atopic conditions is particularly intriguing [2,81,85]. Immune system sensitivity may play a role in the response to hair follicles in AA particularly in light of variations in susceptibility due to male and female hormone levels that have been recognized in allergies [98].…”

“…Regrowth may occur in one region of the scalp while alopecia develops in another area. Hairs at the periphery of affected skin are frequently exclamation mark-or club-like in appearance [2].…”

“…At any one time between 0.05 and 0.1% of the population will express some form of the disease [2,3]. AA results from selective damage to anagen stage hair follicles and is manifested by patchy areas of hair loss on the scalp and other parts of the body that can progress to complete loss of all body hair.…”