Alopecia areata, a medical term for localized hair loss. This is known as Tak Poka in some eastern Indian states especially Bengal because of the notion among the local people that this (hair loss or TAK) is caused by some insects (POKA). This is a misnomer because this condition is neither caused by insects nor any microorganisms.
Actually, alopecia areata is an example of autoimmune disease. Autoimmune disease means a condition when body protective cells like T cells (lymphocytes) or the protective antibodies, in-stead of protecting the body, damage the self-organs. Here, self defense cells (T cells) destroy the hair follicles.
Some thyroid disease and diabetes mellitus are other examples of similar autoimmune diseases. Many of the autoimmune disease may be but not necessarily present simultaneously in an individual. Thus a search for these conditions should be ideally made when a case of alopecia areata is found.
This condition has almost no symptoms except some itching in some cases. Patients detect this condition incidentally. Frequently, the barbers identify this more commonly than the patients himself.
Hair loss is much localised, usually round, having a diameter of few centimeters. One or many patches are found. Most frequently found on scalp but this can affect other hairy areas like eye brows and beard areas. Some cases progress fast with increase in size and number. Severe disease may affect entire scalp or even entire body.
This is not contagious. Patient is otherwise healthy. Some patients might have associated other autoimmune diseases.
Some patient might have nail abnormality in the form of nail pits.
Dermatologists can diagnose this easily. Some patients pull their hair and develop very similar appearing loss of hair. These patients have stress or some form of depressive illness. This condition is called trichotillomania. Sometimes, fungal infection may mimick this.
Dermatoscopy is a valuable tool to diagnose this. Biopsy is required in rare cases.
Consult a dermatologist for proper advice and guidance. Some topical medicinal creams (e.g. steroid creams) are usually advised. Injections within the affected patches are very useful. Many patients think such injects may go inside brain. But this is not true. Some cases may even need oral drugs.