Term Topic content Dyschromia refers to skin discolouration or patches of uneven colour that can appear on the skin. Your skin colour mainly depends upon the amount of brown pigment () in your skin.

Your initial skin colour from birth is changed through your lifetime by how much exposure you have to ultraviolet radiation from the sun.

The amount of melanin in skin can also be the result of other factors such as heat, heavy metals, hormones and trauma through ionizing radiation. Changes in these factors can result in temporary or permanent (increase in pigment production) and/or (decrease in pigment production).

Mottling, or mottled skin, is another type of dyschromia in which changes in the blood vessels cause a patchy appearance. What causes The causes of dyschromia are many, but the most common dyschromia? of these is accumulated sun exposure, especially recurrent sunburns or suntans. Otherwise, sensitivity to the sun can be heightened as a side effect from some medications. Dyschromia can also result from the healing process of wounds and minor skin infections where discolouration, known as post-inflammatory hyperpigmentation (PIH) remains. Generally, the darker your complexion, the darker your PIH will be. Pigmentation is also affected by birthmarks such as café-au-lait spots, Mongolian blue spots and other harmful or harmless spots such as seborrhoeic keratoses (senile warts), moles and malignant melanoma. Radiation therapy can also cause dyschromia. • Hyperpigmentation in skin is caused by an increase Classification in melanin, the substance in the body that is responsible for color (pigment). Certain conditions, such as pregnancy or Addison's disease (decreased function of the adrenal gland), may cause a greater production of melanin and hyperpigmentation. Exposure to sunlight is a major cause of hyperpigmentaion, and will darken already hyperpigmented areas. Hyperpigmentation can also be caused by various drugs, including some antibiotics, antiarrhythmics, and antimalarial drugs.

• Hypopigmentation in skin is the result of a reduction in melanin production.

specialized skin cell that produces the protective skin- darkening pigment melanin. Birds and mammals possess these pigment cells, which are found mainly in the epidermis, though they occur elsewhere—e.g., in the matrix of the hair. are branched, or dendritic, and their dendrites are used to transfer pigment granules to adjacent epidermal cells.

All melanocytes, whether resident in the basal epidermis or in the matrix of the hair, have migrated there during embryonic life from a region known as the neural crest. Each epidermal melanocyte is associated with a group of neighbouring keratinocytes (keratin-synthesizing epidermal cells) into which its dendrites transfer pigment. This structure is known as an epidermal melanocyte unit. The melanin produced by melanocytes is of two kinds: dark brown eumelanin and pale red or yellowish phaeomelanin. Both are formed within the melanocytes by the initial oxidation of the amino acid tyrosine with the aid of the enzyme tyrosinase; subsequently their synthetic pathways diverge.

An increase in melanin pigmentation may be caused by an increased density of melanocytes, by abnormal packaging of melanin, or by increased melanin production. Pigmented birthmarks usually reflect local increases in melanocyte numbers, but in certain rare congenital pigmentary disorders, such as von Recklinghausen neurofibromatosis, there is abnormal packaging of melanin within the melanocytes. Pigment production in the skin is regulated by a pituitary gland peptide hormone called melanocyte- stimulating hormone, and the increase in melanin pigmentation seen with pituitary tumours may reflect overproduction of this hormone by the pituitary. Both suntans and postinflammatory pigmentation result from the overproduction of melanin.

Types of Melanin People have three types: • Eumelanin makes mostly dark colors in hair, eyes, and skin. There are two types of eumelanin: brown and black. Black and brown hair come from different mixes of black and brown eumelanin. Blonde hair happens when there’s a small amount of brown eumelanin and no black eumelanin. • Pheomelanin colors the pinkish parts of your body like the lips and nipples. You get red hair when you have the same amount of pheomelanin and eumelanin. Strawberry blonde hair happens when you have brown eumelanin and pheomelanin. • Neuromelanin Controls the colors of neurons. It isn't involved with the coloring of things you see. An example of hyperpigmentation is melasma. This condition is characterized by tan or brown patches, most commonly on the face. Melasma can occur in pregnant women and is often called the "mask of pregnancy;" however, men can also develop this condition. Melasma sometimes goes away after pregnancy. It can also be treated with certain prescription creams (such as hydroquinone).

Symptoms of melasma Melasma causes patches of discoloration. The patches are darker than your usual skin color. It typically occurs on the face and is symmetrical, with matching marks on both sides of the face. Other areas of your body that are often exposed to sun can also develop melasma.

Brownish colored patches usually appear on the: cheeks forehead bridge of the nose chin It can also occur on the neck and forearms. The skin discoloration doesn’t do any physical harm, but you may feel self-conscious about the way it looks.

Causes and risk factors of melasma It isn’t totally clear what causes melasma. Darker-skinned individuals are more at risk than those with fair skin. Estrogen and progesterone sensitivity are also associated with the condition. This means birth control pills, pregnancy, and hormone therapy can all trigger melasma. Stress and thyroid disease are also thought to be causes of melasma.

Additionally, sun exposure can cause melasma because ultraviolet rays affect the cells that control pigment (melanocytes).

How is melasma diagnosed? A visual exam of the affected area is often enough to diagnose melasma. To rule out specific causes, your healthcare professional might also perform some tests.

One testing technique is a Wood’s lamp examination. This is a special kind of light that’s held up to your skin. It allows your healthcare professional to check for bacterial and fungal infections and determine how many layers of skin the melasma affects. To check for any serious skin conditions, they might also perform a biopsy. This involves removing a small piece of the affected skin for testing.

Is melasma treatable? For some women, melasma disappears on its own. This typically occurs when it’s caused by pregnancy or birth control pills.

There are creams your healthcare professional can prescribe that can lighten the skin. They might also prescribe topical steroids to help lighten the affected areas. If these don’t work, chemical peels, dermabrasion, and microdermabrasion are possible options. These treatments strip away the top layers of skin and may help lighten dark patches.

These procedures don’t guarantee that melasma won’t come back, and some cases of melasma can’t be completely lightened. You might have to return for follow-up visits and stick to certain skin treatment practices to reduce the risk of the melasma returning. These include minimizing your sun exposure and wearing sunscreen daily.

Coping and living with melasma While not all cases of melasma will clear up with treatment, there are things you can do to make sure the condition doesn’t get worse and to minimize the appearance of the discoloration. These include: • using makeup to cover areas of discoloration • taking prescribed medication • wearing sunscreen every day with SPF 30 • wearing a wide-brimmed hat that shields or provides shade for your face • Wearing protective clothing is especially important if you’ll be in the sun for an extended period of time.

Vitiligo causes smooth, white patches on the skin. In some people, these patches can appear all over the body. It is an autoimmune disorder in which the pigment-producing cells are damaged. Almost 1 percent of the world’s population has vitiligo. When you have vitiligo, the cells that are responsible for your skin color are destroyed. These cells, called melanocytes, no longer produce skin pigment, called melanin. Once the cells no longer produce melanin, areas of your skin will lose color or turn white. Areas of lost pigment can develop anywhere on your body, including: • sun-exposed areas like the hands, feet, arms, and face • inside the mouth or other mucus membranes • nostrils • genitals • back of the eye • within the hearing system of the ear • Hair may also turn grey or white if the areas involved have hair.

Even though vitiligo can affect many different parts of the body, it’s not contagious. A person with vitiligo can’t transmit it to someone else

What are the symptoms of vitiligo? The primary symptom of vitiligo is white patches on the skin. And it can affect any area of the body, even the areas around your eyes. The patches can be large or small and appear as one of the following patterns: Segmental or focal: White patches tend to be smaller and appear in one or a few areas. When vitiligo appears in a focal or segmental pattern, it tends to stay in one area one side of the body. Many times it continues for a year or so, then stops. It also progresses slower than generalized vitiligo. Non-segmental or generalized: Widespread white patches appear symmetrically on both sides of the body. This is the most common pattern and can affect pigment cells anywhere on the body. If often starts and stops many times over the course of a person’s lifetime. There’s no way to determine when, if, or how fast patches will develop.

Trusted Source showed that 75 percent of people with vitiligo have loss of pigment on the hands and face. Other common areas are in body folds, like the skin under your arms and around your groin.

What increases your risk for vitiligo? It’s unknown exactly what causes vitiligo. The condition doesn’t appear to be inherited. Most people with vitiligo don’t have a family history of the disorder. But family history of vitiligo or other autoimmune conditions may increase your risk even though it doesn’t cause vitiligo.

Another risk factor may be having genes associated with vitiligo, including NLRP1 and PTPN22

Most researchers believe that vitiligo is an autoimmune disorder because your body is attacking your own cells. But it’s also unclear how your body attacks your pigment cells. What is known is that about 20 percentTrusted Source of people with vitiligo also have one other autoimmune disorder. Depending on the population, these disorders can include the following, from most common to least common: • scleroderma, a disorder of the connective tissue of the body • lupus • thyroiditis, caused by an improperly functioning thyroid • psoriasis • alopecia areata, or baldness • type 1 diabetes • pernicious anemia, an inability to absorb vitamin B- 12 • Addison’s disease • rheumatoid arthritis

What are the complications of vitiligo? The good news is that many times vitiligo has few physical side effects on the body. The most serious complications may affect the ears and eyes, but these aren’t common. The primary physical effect is that the loss of pigment that increases your risk for sunburn. You can protect your skin by applying sunscreen with a SPF of 30 and wearing sun protective clothing.

Psychological effects Research shows that vitiligo can cause significant psychological effects. Scientific reviewsTrusted Source show that over 50 percent of people with vitiligo reported negative effects on their relationships. Some people reported thinking about their condition all day, especially due to the unpredictability of it. They also reported: • avoiding physical activities • withdrawing from events • feeling like their condition is a disfigurement • depression • anxiety • emotional burden If you have vitiligo and are feeling any of these negative effects, talk to your doctor or someone who cares about you. It’s also important to learn as much as you can about the disorder. This can help alleviate stress you may have about your condition or treatment options.

Diagnostic: During your visit, your doctor will perform a physical exam, ask about your medical history, and conduct lab tests. Be sure to report any events that could be contributing factors, like recent sunburns, premature graying of your hair, or any autoimmune diseases you may have. Also let your doctor know if anyone else in your family has vitiligo or other skin diseases. Others questions your doctor may ask are: Where on your body did it first start? Does anyone in your family have vitiligo? Does anyone in your family have an autoimmune disorder? Have you tried any treatments already? Are any areas getting better or worse? Your doctor may also use an ultraviolet lamp to look for patches of vitiligo. The lamp, also known as Wood’s lamp, helps your doctor look for differences between vitiligo and other skin conditions.

At times your doctor may want to take a sample of skin, known as a biopsy. The lab will look at these samples. Skin biopsies can show if you still have pigment-producing cells in that area of your body. Blood tests can help diagnose other problems that may go along with vitiligo, such as thyroid problems, diabetes or anemia.

What are your treatment options? Treatments for vitiligo aim to restore color balance to your skin. Some treatments aim to add pigment while others remove it. Your options will vary according to: • the severity of your condition • the location and size of your patches • how many patches you have • how widespread the patches are • how you respond to treatment The types of treatments include medical, surgical, or a combination of both. But not all treatments work for everyone and some may cause unwanted side effects.

Medical You’ll usually need at least three months of treatment before you can see its effects. Medical treatments include:

Topical creams: Some creams, including corticosteroids, can help return color to white patches in the initial stages. Others help slow the growth. You’ll need a prescription for creams that are strong enough, but they can also cause side effects when used for a long time. Side effects can include: • skin shrinkage • thinning • excess hair growth • skin irritation Oral medications: Some medications like steroids and certain antibiotics may be effective in treating vitiligo. These are only available by prescription.

Psoralen and ultraviolet A (PUVA) therapy: This treatment combination requires you to take psoralen as a pill or apply it to your skin as a cream. Then your doctor exposes you to UVA light to activate the drugs which help restore color to your skin. Afterwards, you’ll need to minimize sun exposure and wear protective sunglasses. PUVA does have side effects that can include:

• sunburn • nausea • itching • hyperpigmentation Narrow band UVB light: This is an alternative to traditional PUVA therapy. This treatment provides a more focused type of light therapy often leading to fewer side effects. It can also be used as part of a home treatment program under a doctor’s supervision.

Excimer laser treatment: This treatment helps with small areas of patches and takes less than four months, two to three times per week.

Surgical Surgical options are available when medications and light therapy don’t work. Your doctor can recommend surgical options if you have had no new or worsening white patches in the last 12 months, and your vitiligo wasn’t caused by sun damage.

The types of surgery include: Skin grafting: Your surgeon removes healthy, pigmented skin and transfers it to depigmented areas. Risks of skin grafting include infection, scarring, or failure to re-pigment. Skin grafting using blisters is another option that has less risks. For this procedure, your doctor will create blisters on your unaffected skin and transfer the top of the blister to another area.

Melanocyte transplants: Your doctor removes melanocytes and lets them grow in a lab. Then, the cells are transplanted to the depigmented areas of skin.

Micropigmentation: Your doctor will tattoo pigment into your skin. This is best for the lip area, but it may be hard to match your skin’s color.

Other therapies and management options Even if you are undergoing medical treatment for vitiligo, the results can be slow. So, you may want to incorporate the following:

Sunscreen: Reducing sun expose can help keep your skin even. Tanning will add contrast to your skin, making affected areas more visible. The higher the SPF, the more protection you receive. It is important to use sunscreen as areas without pigmentation are susceptible to sunburns and sun damage.

Cosmetics: Makeup or self-tanning lotions can help even out your skin tone. You may prefer self-tanning lotions because the effect lasts longer, even with washing.

Managing mental health: One study suggests that medication and psychotherapy can improve your quality of life. Talk to your doctor if you are experiencing negative mental health effects.

Coping with emotional aspects of vitiligo Research shows that people with vitiligo tend to develop issues around emotional stress and self-esteem. One study also found that parents of children with vitiligo report lower for quality of life. But vitiligo isn’t contagious nor does it cause any negative physical effects. People with vitiligo can live a healthy, active life.

It is important to find a therapist who understands this skin condition and its impact on mental health. Early, but limited, studies of individual cognitive behavior therapy (CBT) and vitiligo suggest it can help with:

maintaining self-esteem preventing depression improving overall quality of life Along with your family and friends, a vitiligo support group is a great source of support. These groups give patients the opportunity to express themselves and meet others with the same condition. You can also look at the #vitiligo hashtag on social media for stories of people embracing their appearance. One example is fashion model and activist Winnie Harlow who calls herself a “vitiligo spokesmodel.”

Albinism is a rare inherited disorder caused by the absence of an enzyme that produces melanin. This results in a complete lack of pigmentation in skin, hair, and eyes. Albinos have an abnormal gene that restricts the body from producing melanin. There is no cure for albinism. People with albinism should use a sunscreen at all times because they are much more likely to get sun damage and skin cancer. This disorder can occur in any race, but is most common among whites. Pigmentation loss as a result of skin damage: If you've had a skin infection, blisters, burns, or other trauma to your skin, you may have a loss of pigmentation in the affected area. The good news with this type of pigment loss is that it's frequently not permanent, but it may take a long time to re- pigment. Cosmetics can be used to cover the area, while the body regenerates the pigment.

What are the types of albinism? Different gene defects characterize the numerous types of albinism. Types of albinism include: • (OCA) OCA affects the skin, hair, and eyes. There are several subtypes of OCA: OCA1 OCA1 is due to a defect in the tyrosinase enzyme. There are two subtypes of OCA1:

OCA1a. People with OCA1a have a complete absence of melanin. This is the pigment that gives skin, eyes, and hair their coloring. People with this subtype have white hair, very pale skin, and light eyes. OCA1b. People with OCA1b produce some melanin. They have light-colored skin, hair, and eyes. Their coloring may increase as they age. OCA2 OCA2 is less severe than OCA1. It’s due to a defect in the OCA2 gene that results in reduced melanin production. People with OCA2 are born with light coloring and skin. Their hair may be yellow, blond, or light brown. OCA2 is most common in people of African descent and Native Americans.

OCA3 OCA3 is a defect in the TYRP1 gene. It usually affects people with dark skin, particularly Black South Africans. People with OCA3 have reddish-brown skin, reddish hair, and hazel or brown eyes.

OCA4 OCA4 is due to a defect in the SLC45A2 protein. It results in a minimal production of melanin and commonly appears in people of East Asian descent. People with OCA4 have symptoms similar to those in people with OCA2.

Ocular albinism is the result of a gene mutation on the X chromosome and occurs almost exclusively in males. This type of albinism only affects the eyes. People with this type have normal hair, skin, and eye coloring, but have no coloring in the retina (the back of the eye).

Hermansky-Pudlak syndrome This syndrome is a rare form of albinism that’s due to a defect in one of eight genes. It produces symptoms similar to OCA. The syndrome occurs with lung, bowel, and bleeding disorders.

Chediak-Higashi syndrome Chediak-Higashi syndrome is another rare form of albinism that’s the result of a defect in the LYST gene. It produces symptoms similar to OCA, but may not affect all areas of the skin. Hair is usually brown or blond with a silvery sheen. The skin is usually creamy white to grayish. People with this syndrome have a defect in the white blood cells, increasing their risk of infections.

Griscelli syndrome is an extremely rare genetic disorder. It’s due to a defect in one of three genes. There only have been 60 known casesTrusted Source of this syndrome worldwide since 1978. It occurs with albinism (but may not affect the entire body), immune problems, and neurological problems. Griscelli syndrome usually results in death within the first decade of life.

What causes albinism? A defect in one of several genes that produce or distribute melanin causes albinism. The defect may result in the absence of melanin production, or a reduced amount of melanin production. The defective gene passes down from both parents to the child and leads to albinism.

Who’s at risk for albinism? Albinism is an inherited disorder that’s present at birth. Children are at risk of being born with albinism if they have parents with albinism, or parents who carry the gene for albinism.

What are the symptoms of albinism? People with albinism will have the following symptoms: an absence of color in the hair, skin, or eyes lighter than normal coloring of the hair, skin, or eyes patches of skin that have an absence of color Albinism occurs with vision problems, which may include: • strabismus (crossed eyes) • photophobia (sensitivity to light) • nystagmus (involuntary rapid eye movements) • impaired vision or blindness • astigmatism

How is albinism diagnosed? The most accurate way to diagnose albinism is through genetic testing to detect defective genes related to albinism. Less accurate ways of detecting albinism include an evaluation of symptoms by your doctor or an electroretinogram test. This test measures the response of the light-sensitive cells in the eyes to reveal eye problems associated with albinism.

What are the treatments for albinism? There’s no cure for albinism. However, treatment can relieve symptoms and prevent sun damage. Treatment may include: • sunglasses to protect the eyes from the sun’s ultraviolet (UV) rays • protective clothing and sunscreen to protect the skin from UV rays • prescription eyeglasses to correct vision problems • surgery on the muscles of the eyes to correct abnormal eye movements

Photoprotection Photoprotection is the biochemical process that helps organisms cope with molecular damage caused by sunlight. Plants and other oxygenic phototrophs have developed a suite of photoprotective mechanisms to prevent photoinhibition and oxidative stress caused by excess or fluctuating light conditions. Humans and other animals have also developed photoprotective mechanisms to avoid UV photodamage to the skin, prevent DNA damage, and minimize the downstream effects of oxidative stress. Sunscreen is an important way of protecting the skin against the sun’s harmful rays. By law, a sunscreen product’s label must include a sun protection factor (SPF) number to indicate the level of protection from UVB rays, and state whether or not it has passed a broad-spectrum test against the sun’s ultraviolet (UVA) radiation. The sunscreen innovation act (SIA) governs how this must be done. When we spend time in the sun, we are exposed to two potentially harmful types of ray: UVA and UVB.

Sun protection factor (SPF) is a number, for example, SPF15. It indicates how much protection a product offers against UVB light. A product with a higher SPF number will offer greater protection. According to the FDA, the use of a sunscreen with an SPF of 15 or above, combined with other measures, such as wearing sunglasses and avoiding the midday sun, can help prevent skin cancer. Protection levels are expressed as follows: • Low protection: SPF is below 15 • Medium protection: SPF is 15 to 29 • High protection: SPF is 30 to 49 • Very high protection: SPF is over 50 SPF is a scientific measure. It gives an idea of how much lower the risk of skin damage is due to the use of a sunscreen. It focuses on the time it takes for UVB rays to get through a sunscreen and cause the skin to go red, compared with the time this takes when there is no sunscreen. The factor is calculated by dividing the sun radiation dose needed to cause skin reddening with the dose needed to cause reddening without sunscreen. SPF = sunburn radiation dose with sunscreen / sunburn radiation dose without sunscreen This calculation is based on the application of 2 milligrams (mg) of sunscreen for each square centimeter (cm) of skin surface. If it takes 15 times longer to burn the skin with a sunscreen on than it does with no sunscreen applied, the SPF is 15. In theory, if, under certain UV conditions, it would take 10 minutes for unprotected skin to start going red, an SPF 30 sunscreen would prevent this for 300 minutes, or 5 hours, which is 30 times longer. It is wrong to think, however, that with a higher SPF, a person can spend longer in the sun. These include: • weather conditions • time of day • skin type • how the lotion is applied • how much is used • other environmental and individual factors