Hyperpigmentation (stains, if you will) disorders of the skin
are common. [Photo credit.] The most common are melasma and
postinflammatory hyperpigmentation (PIH). These "stains" are the
result of an increase in cutaneous melanin deposition either by
increased melanin synthesis or, less commonly, by a greater
number of melanocytes. The amount of color change will depend on
the location of the melanin deposition. Epidermal involvement
will appear as brown-grey discolorations. Epidermal deposition
of melanin is enhanced with the use of a Wood's lamp (dermal is
not). The mixed type hyperpigmentation will have enhancement in
some areas, but not in others with the Wood's lamp. Dermal
hyperpigmentation is much more challenging to treat. Melasma
occurs mainly in women (more than 90% of cases) of all racial
and ethnic groups, but particularly in those with Fitzpatrick
skin types IV-VI. The cause of melasma is unknown, but factors
such as genetic predisposition, UV light exposure, and estrogen
exposure play a large pa