Multiple, reticulated, dark brown colored, macules and patches suddenly developed on the fac, and neck of a 48-year-old Korean woman two days after a traffic accident. On physical examination and laboratory tests including serum melanocyte-stimulating hormone, estrogen and progesterone level, no abnormalities were found except cervical pain. Histological examination of hematoxylin-eosin stained sections revealed increased melanin pigmentation in the basal layer, but the number of melanocytes was not changed in DOPA stained section. Topical application of 2% hydroquinone and 20% azelaic acid ointments had been applied successively for two months each without any apparent improvement.