Alopecia areata is thought to be an auto-immune disease of the hair, initially appearing as a rounded bare patch about an inch across. Alopecia areata affects both men and women equally and is often experienced first in childhood. According to a survey taken in America one person in every hundred is likely to experience Alopecia areata at sometime in their life. Many people affected with Alopecia areata will only have one experience of hair loss with regrowth occurring afterwards, however it is estimated that in approximately 20 percent of cases in the UK hair loss recurs or becomes permanent.
There are three types of Alopecia areata which are named according to their severity.
Alopecia areata is mild patchy hair loss on the scalp
Alopecia totalis is the loss of all scalp hair
Alopecia Universalis is the loss of scalp and all body hair
Researchers believe that Alopecia areata is an auto-immune disease, this means that the body’s immune system acts as if the hair follicles are foreign and attacks them. White blood cells called T-lymphocytes attack the hair follicle which causes the hair to stop growing and enter into the telogen (resting) phase, then about 3 months later, when the resting phase is over the hair will then fall out. Only when T-lymphocytes stop attacking the hair follicle will new hair grow.
Medical treatments for Alopecia areata
There is no cure for Alopecia areata, there are only treatments, these treatments must be continued until the condition stops which in most cases happens within a very short time, with or without treatments. Treatments for Alopecia areata are roughly divided into two groups.
1) patients with less than 50% hair loss
2) patents with over 50% hair loss
Alopecia Areata treatment when there is less than 50% hair loss
In mild cases of alopecia areata the first choice of treatment would be a cortocosteroid cream or lotion which is applied directly to the bald areas. An alternative is an injection of cortocosteroid directly onto and around the bald area.
Dithranol is a tar-like ointment which is applied to the scalp and is best known for its use in the treatment of psoriasis. It acts against cell division and discourages overgrowth of the outermost layer of skin cells.
Retin A – Tretinoin
Retin A is normally used in the treatment of acne vulgaris, however has more recently been used in the treatment of both Alopecia areata and Androgenetic alopecia. Usually Retin-A in a gel form is rubbed on the area of hair loss. The gel works best when used in combination with topical minoxidil. It is suggested that minoxidil be applied in the morning and retin-A in the evening due to the fact that retin-a increase the skins sensitivity to sunlight.
Topical Minoxidil marketed as Regaine, Rogaine or Headway
Topical minoxidil is mainly used by individuals with androgenetic alopecia however it is also effective on patchy alopecia areata. Unfortunately topical minoxidil is not normally effective in individuals with 100% scalp loss. Topical minoxidil acts as a temporary measure in alopecia areata, bridging the gap until hair starts growing again on its own.
Oral zinc has been shown to be of occasional benefit in Alopecia Areata and appears to possess an immunomodulatory effect as well as an anti-androgenetic effect. However very high doses are needed for it to be effective and this may result in side effects which can include vomiting and diarrhoea.
Treatments for greater than 50% hair loss
Oral cortisone is sometimes prescribed for extensive scalp loss or when the condition is rapidly spreading. According to the National Alopecia Areata foundation of America, cortisones taken internally are much more powerful than local injections into the skin.
Puva treatment involves taking a psoralen which is a light sensitive drug and then undergoing a short exposure to UVA which is a long-wave ultraviolet light. Treatment takes place over a three to six week period with sessions two to three times a week.
When irritants or allergens are applied to the scalp they cause an allergic reaction. This allergic reaction then draws the T-lymohcytes away from the hair follicle, thus allowing the hair a chance to start regrowing.
Immuno suppressive drugs where developed to stop the immune system from rejecting transplanted organs following transplant surgery. It is thought that the same drugs should be able to suppress the immune system however he main problem with interfering with the immune system is that it can lead to a lowered resistance to infection.