Alopecia areata is a common autoimmune skin disease, causing patches of hair loss on the scalp, face and sometimes on other areas of the body. In fact, it affects more than 10 millions of people worldwide. People of all ages, both sexes, and all ethnic groups can develop alopecia areata.
The cause of Alopecia areata is unknown. The most related theory which holds water is that alopecia areata is a T-cell–mediated autoimmune condition that is most likely to occur in genetically predisposed individuals.
Alopecia areata is also known as a polygenic disease which means both parents must contribute some specific genes for a child to develop it. It is a genetic disease but, chances of transmitting it to children are less. Further confirming, that even if a person has a genetic predisposition, he gets affected only when favorable environmental factors contribute.
This autoimmunity is due to some factors, the significant one being emotional stress. Stress may be in the form of prolonged worry, disappointments, etc.
What is autoimmunity?
Alopecia areata is an autoimmune disease. Autoimmunity means where body’s immune system mistakenly attacks own body cells. In the case of alopecia, the body attacks its hair follicles leading to hair loss in affected area.
- This autoimmunity precipitates due to a few factors, such as genetic, hormonal or environmental factors. Environmental factors may include acute illness, nutritional deficiencies, use of certain medicines.
- High levels of male hormones in men and women may trigger autoimmunity.
- Other autoimmune diseases like underactive thyroid, diabetes mellitus may be seen in the same patient or the family history.
- Use of certain medicines for a long duration may cause alopecia such as oral contraceptive pills, large doses of vitamin A or chemotherapy drugs.
- Excessive exposure to chemicals may damage hair and can trigger autoimmunity.
- Lack of nutritious diets such as inadequate iron and protein intake may cause alopecia.
- Few infections like fungal or lichen planus of the scalp may produce alopecia.