In<unk> , a hair follicle is attacked by the immune system. T-cells swarm the roots, killing the follicle. This causes the hair to fall out and parts of the head to become bald.<unk>  is thought to be a systemic autoimmune disorder in which the body attacks its own anagen hair follicles and suppresses or stops hair growth. For example, T cell lymphocytes cluster around affected follicles, causing inflammation and subsequent hair loss. Hair follicles in a normal state are thought to be kept secure from the immune system, a phenomenon called immune privilege. A breach in this immune privilege state is considered as the cause of<unk> . A few cases of babies being born with congenital<unk>  have been reported.<unk>  is not contagious. It occurs more frequently in people who have affected family members, suggesting heredity may be a factor. Strong evidence of genetic association with increased risk for<unk>  was found by studying families with two or more affected members. This study identified at least four regions in the genome that are likely to contain these genes. In addition,<unk>  shares genetic risk factors with other autoimmune diseases, including rheumatoid arthritis, type 1 diabetes, and celiac disease. It may be the only manifestation of celiac disease. Endogenous retinoids metabolic defect is a key part of the pathogenesis of the<unk> . In 2010, a genome-wide association study was completed that identified 129 single nucleotide polymorphisms that were associated with<unk> . The genes that were identified include those involved in controlling the activation and proliferation of regulatory T cells, cytotoxic T lymphocyte-associated antigen 4, interleukin-2, interleukin-2 receptor A, and Eos (also known as Ikaros family zinc finger 4), as well as the human leukocyte antigen. The study also identified two genes, PRDX5 and STX17, that are expressed in the hair follicle.
Alopecia areata
Hair loss
Alopecia mucinosa
Trichotillomania
Alopecia universalis
Alopecia totalis
Loose anagen syndrome
Alopecia neoplastica