Thyroid autoimmunity in patients with alopecia areata.

Alopecia areata (AA) is a common form of localized, non-scarring hair loss. It is characterized by the loss of hair in patches, total loss of scalp hair (alopecia totalis), or total loss of body hair (alopecia universalis). The etiopathogenesis of the disease is still unclear, but there is evidence that autoimmunity and endocrine dysfunction may be involved.