NEW YORK (Reuters Health) - Several natural health products have been investigated for treating the pigmentation disorder vitiligo, but overall, the quality of the research is poor, the authors of a new review conclude.
Of the products reviewed, only Gingko biloba taken orally and the amino acid L-phenylalanine, administered along with light exposure, showed promise, the researchers found.
“The need to find a safe and effective treatment is particularly important with vitiligo, where up to 50% of cases develop in the pediatric population; at a time when the condition has the greatest impact on psychological development,” Drs. Orest Szczurko and Heather S. Boon of the University of Toronto report in the BioMed Central journal Dermatology.
Vitiligo occurs when cells that produce the pigment melanin stop functioning, leaving white patches on the skin. Up to 4 percent of certain ethnic groups have vitiligo, note the researchers, while as many as 35 percent of vitiligo patients have psychiatric problems related to the condition, including depression, anxiety and suicidal thoughts.
Three recent reviews of conventional therapies for vitiligo have concluded that topical steroids may be helpful, while treatment with ultraviolet A or ultraviolet B (UVA or UVB) light alone or along with medications known as psoralens or calcipotriol may also be effective, Szczurko and Boon add. However, the researchers note, both therapies can have problematic side effects.
To investigate the effectiveness and safety of natural products for treating vitiligo, Szczurko and Boon undertook a systematic review of all published research, identifying 15 controlled trials.
Three of the trials looked at L-phenylalanine with UVA or UVB therapy, and one looked at L-phenylalanine in combination with other drugs. While all these trials showed benefits, the authors say, each had problems including high numbers of dropouts and the lack of a control group.
Three trials looked at Chinese herbs for vitiligo, but all were of “poor methodological quality,” the researchers say.
Six investigated plant products alone or with phototherapy, with “moderate” evidence for the benefit of Gingko biloba and only weak evidence for other plant products.
Studies of vitamins found no evidence of benefit for cobalamin and folic acid along with phototherapy, and weak evidence for vitamin E plus phototherapy.
“Gingko’s apparent efficacy without the need for phototherapy, thus eliminating the adverse events inherent with phototherapy, make it a therapeutic option worth investigating,” they write, calling for more research into the use of the herb as well as L-phenylalanine.
SOURCE: BMC Dermatology, May 22, 2008.