Review of liver function, tumor markers and tumors after long-term topical use of 1% kojic acid cream

We have used kojic acid (KA) for clinical treatment of various facial pigmentary disorders such as liver spots (melasma), solar lentigo, nevus of Ota, ephelid and pigmented cosmetic dermatitis (PCD). To confirm the effectiveness and safety of long-term use of KA, we have followed 16 patients who had used 1% KA cream for an average 2 years and 8 months. The longest period of usage was 7 years and 11 months. Results of liver function tests, complete blood count and tumor markers, including alpha fetoprotein, did not reveal any abnormalities due to the use of KA. In addition to our findings, we found no reports of cancer production or induction of skin cancers due to the topical application of 1% KA creams. In conclusion, the topical whitener, kojic acid, can be used safely for various facial pigmentary disorders.