Some of the #terminology used in connection with #vitiligo can be a bit baffling at first for those of us who aren’t medically trained, so I have put together an alphabetical glossary of some of the most frequently used terms. I hope you find it helpful as you trawl the internet in search of answers :)
AETIOLOGY (alternative spelling: ETIOLOGY) - the study of the causes of a disease.
ANTIOXIDANT - an enzyme or other organic substance, as vitamin E or beta carotene, capable of counteracting the damaging effects of oxidation in animal tissues.
AUTO-IMMUNITY - a misdirected immune response that results in the production of antibodies that mistakenly attack the tissues of your own body. (Vitiligo is generally believed to be an auto-immune disease in which the body’s own defence system attacks its own pigment–producing cells.)
CATALASE - an enzyme that breaks down hydrogen peroxide into oxygen and water.
CUTANEOUS – relating to the skin.
EPIDERMIS – the outer layer of the skin.
FREE RADICAL - free radicals are molecules with unpaired electrons. In their quest to find another electron, they are very reactive and cause damage to surrounding molecules.
HYDROGEN PEROXIDE – a combination of hydrogen and oxygen. Its chemical description is H2O2. In high concentrations it can be unstable and toxic. In lower concentrations it can serve as a disinfectant and antiseptic. Its use on wounds is no longer recommended as it can damage live skin. Organisms naturally produce hydrogen peroxide as a by-product of oxidative metabolism. Hydrogen peroxide has been shown to play a role in the immune system and research shows that vitiligo sufferers typically have higher levels of it on their skin than people without vitiligo.
HYPERPIGMENTATION - the darkening of an area of skin or nails caused by increased melanin.
HYPOPIGMENTATION - the loss of skin colour due to melanin depletion.
HYPERTHYROIDISM – (often referred to as an overactive thyroid gland) is a condition in which your thyroid produces too much thyroxine, the hormone that helps regulate the adrenal system, plays a role in energy, normal growth and development, as well as the ability to maintain a healthy weight, and in mood stability.
HYPOTHYROIDISM - (often referred to as an underactive thyroid gland) is a condition in which your thyroid produces too little thyroxine, the hormone that helps regulate the adrenal system, plays a role in energy, normal growth and development, as well as the ability to maintain a healthy weight, and in mood stability.
LESION – an abnormal change involving any tissue or organ – in the case of vitiligo, it is skin - due to disease or injury.
LEUCODERMA (alternative spelling: LEUKODERMA) - localised loss of pigmentation in the skin. This can be due to a variety of causes, not purely vitiligo.
MACULE - a patch of skin that is altered in colour but usually not raised and that is a characteristic feature of various diseases (including vitiligo).
MELANIN - the pigment that gives human skin, hair, and eyes their colour. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes. It provides some protection again skin damage from the sun, and the melanocytes increase their production of melanin in response to sun exposure. Freckles, which occur in people of all races, are small, concentrated areas of increased melanin production.
MELANOCYTE - Melanocytes are cells located in the epidermis that are responsible for producing melanin, the brown pigment that gives skin its colour and helps screen against the harmful effects of UV light.
NON-SEGMENTAL VITILIGO – the most common type of vitiligo, in which white patches develop in a broadly symmetrical pattern. New patches also appear over time and can be generalised over large portions of the body or localised to a particular area.
OXIDATIVE STRESS - an imbalance between the production of free radicals (see definition above) and the ability of the body to counteract or detoxify their harmful effects through neutralisation by antioxidants.
PIGMENT - a substance that gives colour to tissue – in the case of the human body, pigments are responsible for the colours of skin, eyes, and hair.
PSEUDOCATALASE – (also called Pcat for short) is a vitiligo treatment cream that is applied twice a day in order to reduce epidermal hydrogen peroxide in vitiliginous skin. Pseudocatalase is usually used in combination with narrow band UVB light therapy.
SEGMENTAL VITILIGO - differs in appearance, aetiology and treatment from non-segmental vitiligo. It tends to affect one particular section of skin (or possibly several) and is unilateral instead of symmetrical in its distribution.
THYROID - the thyroid gland is an endocrine gland in your neck. It makes two hormones that are secreted into the blood: thyroxine (T4) and triiodothyronine (T3). These hormones are necessary for all the cells in your body to work normally. Thyroid disorders are very common and tend mainly to occur in women, although anybody - men, teenagers, children and babies, too - can be affected. About one in twenty people has some kind of thyroid disorder, which may be temporary or permanent.
TOPICAL - A topical medication is a medication (usually a cream, foam, gel or ointment) that is applied to body surfaces such as the skin to treat ailments.
UVA - UVA is a long wavelength (320-400nm) of ultraviolet light that penetrates both the epidermis and dermis (i.e. both the upper and lower levels of the skin). It causes skin tanning, but also the unwanted concerns of brown spot formation premature wrinkling and risk of skin cancer. Most commercial tanning beds emit UVA light.
UVB - UVB is a short wavelength (290-320nm) of ultraviolet light that affects primarily the epidermis and does not penetrate as deeply as UVA but can cause sunburn and also carries the risk of skin cancer. (NB-UVB or Narrow Band UVB is ultraviolet light in a narrow band 311nm to 313 nm and is now the preferred form of light therapy as it is thought to be more effective, faster acting, and may be safer than other UV light treatments.)
WOOD’S LAMP (also known as black light or ultraviolet light) – this lamp can be used to identify vitiliginous lesions more clearly than in normal lighting conditions. Skin with vitiligo, when exposed to a black light, will glow yellow, green or blue, in contrast to healthy skin which will have no reaction.
I only realised when I read the following web page:
http://www.dermnetnz.org/colour/leukoderma.html that - contrary to popular belief - leukoderma and vitiligo are not synonymous. Vitiligo is just one type of leukoderma. Here's what the dermnetnz.org site says:
Leukoderma is the name given to white patches on the skin. These patches are due to the partial or total loss of skin pigmentation. There are many causes of leukoderma. Vitiligo is a specific type of leukoderma and is often, although incorrectly, used interchangeably with the term leukoderma (sometimes spelled leucoderma).
There are many causes of leukoderma, some of which include:
My name is Caroline.