What is alopecia areata? 
Alopecia areata is a common cause of hair loss. It occurs in men and women of all ages, but is more common in children and young adults. It usually causes small round patches of baldness on the scalp. Other hair-bearing areas on the body may be affected. Occasionally it may involve the entire scalp (alopecia totalis) or even the whole body and scalp (alopecia universalis). 

The hair may take a period of months, or even years, to regrow. However, regrowth may not always occur. When the hair loss is extensive, like in alopecia totalis, complete regrowth is less likely to occur. The new hair is sometimes white in colour.
 

What causes alopecia areata? 
Alopecia areata is an autoimmune disease. The body’s own immune cells attack hair follicles resulting in hair loss. Genetic predisposition may play a role. Diet and nutritional deficiencies do not cause alopecia areata. Stress appears to be a triggering factor.
 

How will it affect me? 
Alopecia areata may cause emotional stress, particular in those with extensive hair loss. Depression is not uncommon.
 

Is it associated with any underlying medical problem? 
Alopecia areata may be associated with other autoimmune conditions like thyroid disease, and vitiligo. Where indicated, your doctor may perform blood tests to look for these conditions.

How is alopecia areata treated? 
Treatment of alopecia areata is dependent on how severe the disease is. Very mild cases may not need any treatment at all. The available treatments are:

Topical applications 
Topical steroids and minoxidil may be used. These are usually applied to the bald patches once to twice daily. 

Steroid injections 
This is the most effective treatment for small patches of hair loss. Multiple injections are given to the patches. This is usually repeated on a monthly basis. The injections can be a little uncomfortable and can occasionally result in depression of the skin at the sites of injection. 

Steroid tablets 
Steroid tablets may be used when there is rapidly progressive hair loss. A gradually reducing dose is usually given over a couple of months. As there are potential side-effects from prolonged ingestion of oral steroids, this treatment is generally not continued invariably.

Contact immunotherapy 
Application of diphencyprone to the bald patches causes a contact dermatitis that can result in hair regrowth. The treatment is repeated on a weekly basis for six months to one year, or until the hair is regrown. Side effects include itch, blistering and enlarged lymph nodes. 

Systemics 
Oral medications such as methotrexate, cyclosporine and JAK inhibitors may be used. Your doctor will discuss this with you. 

Topical PUVA
This is a treatment involving the application of a light-sensitizing solution followed by exposing the scalp to ultraviolet light. 

Wigs
Wigs can be helpful for those who do not respond to treatment, or while waiting for the hair to regrow.
 

Can alopecia areata recur?
Complete regrowth of hair is likely to occur in patchy hair loss. The chance of regrowth in severe cases, while still possible, may be less predictable. In patients where the hair has completely regrown, hair loss may recur after a variable period of time at the same or different sites. In some cases, particularly those where there is extensive hair loss, there may only be partial regrowth or even no regrowth at all. There is no known effective method of preventing the recurrence of hair loss