Re: Oral Pigmentation

The oral mucosa is usually not pigmented despite the fact that it has the same density of melanocytes as the skin. Occasional patients, however, will show a focal area of melanin deposition, either as a response to local chronic conditions (mechanical trauma, tobacco smoking, chronic autoimmune mucositis), racial background (the darker a person’s skin color the more likely they are to have oral pigmentation), or systemic medications, especially chloroquine. Moreover, certain syndromes and systemic diseases have oral pigmentation as part of their spectrum (Table 1), as mentioned previously in this section.

Most focal melanin deposits of the oral mucosa which are not associated with race or an appropriate syndrome are innocuous surface discolorations called oral melanotic macule (focal melanosis). This entity represents not only a focal increase in melanin deposition but a concomitant increase in the number of melanocytes. Unlike the cutaneous ephelis (freckle), the oral melanotic macule is not dependent on sun exposure, nor does it show the elongated rete ridges of actinic lentigo. Some authorities have questioned the purported lack of an association with actinic irradiation for melanotic macule located on the vermilion border, preferring to consider the lesion at this site to be a distinct entity called labial melanotic macule. Melanotic macules are found in the mouths of 1 of every 1,000 adults