Dyschromia
What is dyschromia?
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 (melanin) 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 hyperpigmentation (increase in pigment production) and/or hypopigmentation (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 dyschromia?
The causes of dyschromia are many, but the most common 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.
Available treatments
With patience, normal skin colour can often return over time. However, if this is not the case, there are a number of treatment options.
Topical treatments
Topical bleaching agents, such as hydroquinone, has been found to be effective for darkened patches from acne, freckles and resolved skin trauma and it can even out the skin tone for large, hyper pigmented patches (increased colour). Hydroquinone works by circumventing melanin formation, reducing the appearance of darkened patches. Although the oldest and most proven topical treatment, safety concerns have been raised in the use of hydroquinone and should not be used by pregnant women.
Topical treatments derived from natural ingredients include kojic acid mitracarpus scaber extract, bearberry extract, liquorice extract, beta-carotene, gluconic acid, azelaic acid, paper mulberry and vitamin C. They also reduce the appearance of darkened patches and work in a way similar to hydroquinone. These topical treatments are potentially safer, but they are generally less effective.
Protection from the sun is essential during the months of treatment, as sun damage will undermine any progress.
Cosmetics help to hide uneven or mottled skin but they do not solve the underlying problem.
Laser and other light-based options (surgical and non-surgical)
Photorejuvenation is new laser or light-based treatment. It delivers stronger pulses of light deep into the innermost layer of skin, injuring then repairing its collagen. Unlike surgical methods, photorejuvenation does not generally injure the outer layer of skin, therefore minimising the visible signs of the procedure. This therapy reduces the appearance of discoloured patches, freckles, sun damage, fine wrinkles, ageing, redness and the dilated capillaries associated with rosacea.
The light-based treatments are remarkable in their ability to achieve positive results with relatively little discomfort and risk.
Other options include: