Vitiligo is a skin disease in which pigment-making cells, called melanocytes, are destroyed, leaving white irregular patches of skin where pigment used to be. The patches usually appear on the hands, feet, arms, face, and lips, but can also occur on the skin around the mouth, nose, eyes, and genitals. Hair growing from areas affected by vitiligo may also turn white. Although vitiligo in itself is not painful, it can cause emotional distress.

Science has not identified the cause of vitiligo, but some researchers theorize that an autoimmune process plays a role. In an autoimmune disease, the body's immune system starts attacking innocent tissues. In vitiligo, antibodies may develop against melanocytes, ultimately destroying some of them. Vitiligo seems to be more common in people who have other autoimmune diseases; however, most people with vitiligo have no other autoimmune disease.

Most conventional vitiligo treatments combine ultraviolet light (UVA) exposure with oral or topical drugs that selectively sensitize the skin to UVA—such drugs are called "psoralens" because they are most commonly used to treat psoriasis. The results of this treatment are generally reasonably good. Another option is topical corticosteroids, which may be best for localized vitiligo.1 In severe cases, surgical procedures including skin grafting and melanocyte transplantation may be considered, although these approaches are still experimental.

Most natural therapies for vitiligo also employ exposure to UVA or natural sunlight in conjunction with an oral or topical treatment.

Khellin

Khellin, an extract of the fruit of the Mediterranean plant khella ( Ammi visnaga), is closely related to the standard psoralen drug methoxsalen. Both are used in conjunction with UVA to repigment vitiligo patches.

A double-blind, placebo-controlled studyof 60 people indicated that the combination of oral khellin and natural sun exposure caused repigmentation in 76.6% of the treatment group; in comparison, no improvement was seen in the control group receiving sunlight plus placebo.2A subsequent placebo-controlled study of 36 people found that a topical khellin gel plus UVA caused repigmentation in 86.1% of the treated cases, as opposed to 66.6% in the placebo group.3

A typical oral dosage of khellin is 100 mg daily.

Khellin has no reported side effects when used topically. Oral doses, however, have caused various side effects ranging from nausea and vomiting to liver inflammation.

L-Phenylalanine

A handful of preliminary studies suggest that oral L-phenylalanine, a natural amino acid, might also be helpful for vitiligo. It too is combined with either sunlight or controlled ultraviolet light.

Of four studies on the subject, only one was double-blind.4 It found positive results; however, because only 24 people were enrolled, further research will be necessary to confirm its conclusions. The other studies were open, uncontrolled trials, and as such prove little.5,6,7

For more information, including dosage and safety issues, see the full Phenylalanine article.