Normal skin colour
Skin colour is determined by a pigment (melanin) made by specialised cells in the skin (melanocytes). The amount and type of melanin determines a person's skin colour. The variations in skin colour amongst individuals is referred to as the skin phototype and this can vary from skin type 1 (very fair, redhead, blue eyes) to skin type 6 (very dark).
What is the function of melanin?
Melanin gives colour to the skin, hair, and iris of the eyes. Levels of melanin depend on race and amount of sunlight exposure. Sun exposure increases melanin production - to protect the skin against harmful ultraviolet rays. In addition, hormonal changes can affect melanin production.
Pigmentary skin disorders
This occurs when there is a variation in a persons’ baseline skin colour. There may be increased pigment called “hyperpigmentation” or a decrease in pigment called “hypopigmentation”. These variations may involve a small localised area or can involve large body areas.
- This is the commonest cause of hyperpigmentation especially in brown/black skin.
- It may be due to anything that causes injury or inflammation to the skin like burns, rashes like lichen planus, eczema or psoriasis and skin problems like acne. This is caused by the melanin pigment “falling” into the deeper layers of the skin where they become trapped by cells called melanophages.
Melasma or chloasma is a dark brown discoloration of skin found on sun-exposed areas of the face. It is most commonly seen on the cheeks, forehead, nose, or upper lip and is usually symmetrical. It is a common skin disorder mostly affecting young women with brownish skin tones, although it can affect women of any skin type & age. It rarely does also occur in men.
Melasma is often associated with the female hormones oestrogen and progesterone. It is common in pregnant women (“mask of pregnancy”), women who are taking oral contraceptives, and women taking hormone replacement therapy during menopause. Melasma often fades over several months after stopping oral contraceptives or hormone replacement therapy or after delivering a child. It may return with additional pregnancies or with the use of these medications. Sun exposure is also a strong risk factor for melasma. It is particularly common in tropical climates.
People may have patches of pigmentation as since the time of birth. These are usually flat brown patches called CafÃ© au lait macules. They can vary in size from a few millimetres to several centimetres. Some pigmented birth marks may be associated with other internal genetic defects.
TREATMENT OF HYPERPIGMENTATION
This will include creams that contain medical grade vitamin A or a safe bleach ingredient & procedures like microdermabrasion, chemical peels & laser.
- Vitiligo presents as smooth, white patches in the skin and is caused by the loss of pigment-producing cells in the skin (melanocytes). The white patches are very sensitive to the sun
- .The exact cause is unknown but it’s thought that it’s due to the autoimmune destruction of melanocytes.
- Treatment depends on the area and size involved and includes the use of topical creams, phototherapy, laser or grafting techniques.
This is a rare, inherited disorder characterized by a total or partial lack of melanin in the skin, compared to the pigmentation of siblings and parents. Albinos (people with albinism) have white hair, pale skin, and pink eyes. Vision is often affected. There is no treatment of this condition but these patients require strict sun protection as they are at high risk of developing skin cancer.
Sometimes, following an ulcer, blister, burn, rash or infection, the skin does not replace some of the pigment in that area an this area may remain lighter than the skin. This may be temporary as in Tinea versicolor (fungal infection involving the chest & back) or Pityriasis Alba (dermatitis seen on the face of children). However, in some cases like deep burns, this may be permanent.
It is important that the exact nature of the pigmentary disorder be assessed in order to prescribe the correct treatment. In patients who have conditions like lichen planus, eczema, psoriasis and acne, it is vital that these are treated early and appropriately in order to prevent the pigmentation from developing in the first place