Currently there is no reliable or effective treatment available for patchy hair loss otherwise known as alopecia areata, researchers at the University of Tasmania in Australia have suggested.
The finding is based on a review of existing research, which was conducted by Dr. Mike Sladden, a dermatologist and senior lecturer at the University of Tasmania in Australia, and his colleagues.
Alopecia areata often causes patchy hair loss, which means hair in some parts of the body falls out while remaining in others.
However, in some cases, affected patients can lose all of their scalp hair or even all of their body hair.
According to research, alopecia areata is caused when the immune system attacks the hair follicle. Some cases are linked to physical or emotional stress, but others do not have an apparent trigger.
In the review, researchers examined 17 randomised controlled trials of treatments for alopecia areata.
The studies, which looked at 540 patients, measured the effectiveness of several treatments, including topical and oral corticosteroids and topical cyclosporine.
These drugs dampen the immune system to try to stop it from becoming confused and attacking the body.
Other treatments that researchers examined include photodynamic therapy (which exposes the skin to light) and topical minoxidil (Rogaine).
Following the review, researchers could not find any randomised controlled studies of other treatments, including diphencyprone, dinitrochlorobenzene, intralesional corticosteroids and dithranol.
Researchers found that none of the studies showed long-term 'beneficial hair growth,' the return of more than half of the missing hair.
"Few treatments for alopecia areata have been well evaluated in randomized trials and we found none that addressed participant-focused measures of success or measurements of quality of life," the researchers said.
The review is published in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration.