In the auto-immune variety, the body’s immune system attacks and destroys its own hair follicles resulting in patchy hair loss. Unlike the ringworm infection, the auto-immune alopecia areata is not contagious.
In the auto-immune variety, the trigger could be an infection which can be fungal, viral or bacterial. The infection may not be severe but it makes the body produce certain antibodies. The function of these antibodies is to kill the infection but instead it starts destroying the hair follicles. From a localized area, the antibodies then circulate throughout the body causing widespread destruction of hair follicles.
It is not very clear as to why the immune system malfunctions in some people and not in others. But people with a family history are more likely to suffer from this condition. It can equally affect both men and women and is commonly found in people younger than 20.
Auto-immune Alopecia Areata has 2 types. One is the scarring alopecia in which the skin is thickened and scarred with loss of hair follicles. The second is the non-scarring alopecia wherein the hair strand is lost but the follicles are intact, making it the reversible type.