What causes alopecia areata? Be careful about heredity

Alopecia areata, also known as ghost hair loss, is a common hair loss disease in clinical practice. Many people do not know what causes alopecia areata. In fact, this is also a sudden non-inflammatory disease. This disease may occur in any hairy part of the body, so it must be taken seriously.

1. Neuropsychiatric factors (35%):

The cause of the disease is still unclear. Neuropsychiatric factors are considered to be an important factor. Many cases have neuropsychiatric trauma before the onset of the disease, such as long-term anxiety, worry, sadness, mental tension and emotional instability. Sometimes these mental factors can rapidly worsen the patient's condition during the course of the disease.

2. Genetic allergy (20%):

About 10% to 20% of cases have a family history. There are reports of monozygotic twins suffering from alopecia areata in the same part of the body at the same time, and there are also reports of four generations of a family suffering from alopecia areata. It is considered to be a genetic defect disease. From the accumulated clinical evidence, it can be seen that people with a genetic allergic constitution are prone to alopecia areata. According to statistics from the United States, 18% of children with alopecia areata have eczema or asthma, or both; about 9% of adults have alopecia areata; the proportion of children with total alopecia is even higher, accounting for 23%. According to statistics from Japan, 10% of alopecia areata patients have a genetic allergic constitution, while the figure in the Netherlands is as high as 52.4%. However, the basis for the Netherlands to establish a genetic allergic constitution is to include positive skin tests and those with a family history of genetic allergies. Therefore, the diagnostic standards for genetic allergic constitutions in various countries and regions are different, and the data cannot be compared. A study on the correlation between alopecia areata and human leukocyte antigen conducted by Chen Shengqiang in China showed that the frequency of HLA-A9 antigen (16.67%) in alopecia areata patients was significantly lower than that in normal people (32.65%), which supports the genetic allergic factor of alopecia areata from an experimental perspective.

3. Autoimmunity (15%):

The rate of some autoimmune diseases in patients with alopecia areata is higher than that in the normal population, such as thyroid disease, accounting for 0-8%; vitiligo, accounting for 4% (only 1% in normal people). There are different research reports on autoantibodies in patients with alopecia areata, some say they exist, and some say they have not been found. A study on T cell subsets and β2 microglobulin by Zhang Xinjiang in China suggested that patients with alopecia areata have T cell network disorders and humoral immune disorders.

4. Down syndrome (15%):

The incidence of alopecia areata increases in Down syndrome, often alopecia totalis or alopecia universalis, and the presence of autoantibodies in these patients is significantly increased.