Alopecia Areata

It is derived from French word “pelede” meaning patchy hair loss. It is characterized by rapid and complete loss of hair in one or more, round or oval patches, usually on the scalp, beard area, eyebrows, eye lashes and less commonly on the other hairy areas of the body. The incidence is 0.1-0.2% with a projected lifetime risk of 1.7%.

What causes alopecia areata?

It is an autoimmune disease.

What is auto immune?

The body as we all know has an immune system. This immune system is made of various tissues and cells, principal among which are the white blood cells. In short, white blood cells or WBCs are chiefly responsible for protecting the body against the development of infection and various other diseases. The white blood cells constantly police the body and neutralize or eliminate undesirable cells, organisms, microbes and materials. At times, inexplicably, they attack the normal cells of the body. Such a state of affairs is referred to as auto-immunity and diseases resulting thereof are called auto-immune diseases. Depending on the cells and organs involved auto-immune diseases can range from the banal to the fatal. Auto immunity is something like police brutality, a condition where the defender offends.

In alopecia areata, though the hair follicle is targeted by the WBCs, they are not destroyed. The area without hair will have intact, but empty hair follicles from which hair can grow in future.

Sometimes genetic factors with family history of alopecia areata contribute to 20% - 25% of the cause, but environmental factor that trigger the disease is also associated with the genetic factor.

There are various associations between alopecia areata and classic autoimmune disorder, like thyroid disease, vitiligo, pernicious anaemia, diabetes, myasthenia gravis, rheumatoid arthritis, ulcerative colitis, lichen planus.

Generally people get 1-3 patches and lasts for 3-6 months. About one third of people with alopecia areata get repeated bouts of hair loss for spanning years or decades. A small fraction will go onto loose hair all over the scalp or all over the body forever. Fortunately this happens in a small fraction of people with alopecia areata. In most cases, some patients experience mild to moderate itching, pain, burning sensation before the patch had appeared. Nail changes are seen in 10%-66% which is a poor prognostic sign.

People with extensive or recurrent alopecia areata may have other autoimmune diseases and tests detect these may be recommended by the doctor. Most people with alopecia areata will regrow hair spontaneously, especially with limited patchy hair loss of short duration of less than one year, or with treatment. Regrowth can be expected within 3 months of any individual patch.

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