Hypopigmentation is characterized specifically as an area of
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
becoming lighter than the baseline skin color, but not completely devoid of
pigment
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
. This is not to be confused with
depigmentation, which is characterized as the absence of all pigment.
It is caused by
melanocyte
Melanocytes are melanin-producing neural-crest, neural crest-derived cell (biology), cells located in the bottom layer (the stratum basale) of the skin's epidermis (skin), epidermis, the middle layer of the eye (the uvea),
the inner ear,
vagina ...
or
melanin
Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes.
There are ...
depletion, or a decrease in the
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...
tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is ...
, which is used by melanocytes to make melanin.
Some common genetic causes include mutations in the
tyrosinase gene or
OCA2 gene. As melanin pigments tend to be in the skin, eye, and hair, these are the commonly affected areas in those with hypopigmentation.
Hypopigmentation is common and approximately one in twenty have at least one hypopigmented macule. Hypopigmentation can be upsetting to some, especially those with darker skin whose hypopigmentation marks are seen more visibly. Most causes of hypopigmentation are not serious and can be easily treated.
Presentation
Associated conditions
It is seen in:
*
Albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos.
Varied use and interpretation of ...
*
Idiopathic guttate hypomelanosis
*
Leprosy
Leprosy, also known as Hansen's disease (HD), is a Chronic condition, long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the Peripheral nervous system, nerves, respir ...
*
Leucism
*
Phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also r ...
*
Pityriasis alba
*
Vitiligo
Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibili ...
*
Angelman syndrome
Angelman syndrome (AS) is a genetic disorder that affects approximately 1 in 15,000 individuals. AS impairs the function of the nervous system, producing symptoms, such as severe intellectual disability, developmental disability, limited to no ...
*
Tinea versicolor
*
Yaws
* An uncommon adverse effect of
imatinib therapy
* Injections of high concentrations of
corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...
s (transient)
Diagnosis
Areas of lighter pigmentation can be indications of hypopigmentation. Biopsies and genetic information are also used to diagnose.
Treatments
Often, hypopigmentation can be brought on by laser treatments; however, the hypopigmentation can be treated with other lasers or light sources.
Micropigmentation can also be used to obtain a more normal appearance of the hypopigmentated skin.
Treatment for hypopigmentation depends on the initial cause of the discoloration.
See also
*
Hyperpigmentation
Hyperpigmentation, also known as the dark spots or circles on the skin, is the darkening of an area of Human skin, skin or nail (anatomy), nails caused by increased melanin.
Causes
Hyperpigmentation can be caused by sun damage, inflammation, or ...
References
External links
{{Pigmentation disorders
Dermatologic terminology
Disturbances of human pigmentation