Hi,
Most of the time discoloration is superficial. In a few cases, the discoloration lies deep in the dermis. If the pigment is in the epidermis, it can be helped with skin-lightening products. If the pigment is deeper, laser treatments are a consideration. For topical treatments, Topical hydroquinone 2 to 4% alone or in combination with tretinoin 0.05 to 0.1% is an established treatment.
Kojic acid, alone or in combination with glycolic acid or hydroquinone, has shown good
results, due to its inhibitory action on tyrosinase.
Despite its remarkable overall safety
, the physician ought to bear in mind the potential adverse effects. Contact dermatitis occurs in a small number of patients and responds promptly to topical steroids.
ref:http://answers.google.com/answers/threadview?id=737014