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Hyperpigmentation Abnormally increased
pigmentation.
Increased melanin deposition resulting in hyperpigmentation
may be caused by hormonal changes (eg, in Addison's disease, pregnancy, or
anovular pill use). Hyperpigmentation may also result from iron deposition
in hemochromatosis or from silver deposits (eg, in argyria). Long-term
application (years) of hydroquinone is a rare cause of local ochronosis.
Exposure to sunlight is one of the major causes of accentuated skin pigmentation.
Melasma (chloasma)
Consists of dark brown,
sharply marginated, roughly symmetric patches of hyperpigmentation on the
face (usually on the forehead, temples, and malar prominences). Melasma
occurs mainly in pregnant women (melasma gravidarum, the mask of
pregnancy) and in women taking anovular hormones. It may also occur
idiopathically in nonpregnant women and in dark-skinned men.
Hyperpigmentation related to pregnancy fades slowly and incompletely after
childbirth or when related to estrogen use or cessation of hormone
production or use.
Drug-induced hyperpigmentation
of skin is
not uncommon. Postinflammatory hyperpigmentation may follow various
drug-induced and non-drug-related inflammatory dermatoses.
Hyperpigmentation frequently follows lichen planus and lichenoid drug
reactions. Fixed drug eruptions typically leave annular foci of
hyperpigmentation. Other drugs that can cause hyperpigmentation include
amiodarone, tetracycline, minocycline, bleomycin, cyclophosphamide, and
the antimalarials chloroquine and quinacrine. Chlorpromazine and other
phenothiazines may cause grayish blue skin discoloration on sun-exposed
areas. Discoloration of skin due to heavy-metal deposition may occur when
therapeutic drugs containing silver (argyria), gold (chrysiasis), mercury
(hydrargyrosis), and bismuth are used. Except for gold and bismuth, these
compounds are no longer used. |
