Normal skin contains cells called melanocytes that produce the brown skin-coloring pigment melanin. There are several conditions in which melanocytes are either abnormal or abnormally distributed. Most skin conditions that cause discoloration are harmless.
A pale area of the skin is the result of fewer or less active melanocytes than usual, whereas a darker area (or area that tans more easily) indicates more numerous or more active melanocytes.
What about the red/brown marks left behind after acne?
These kind of marks are postinflammatory hyperpigmented lesions and are located at the site of a skin trauma after it has healed.They can result from acne, bites, burns or skin infections. The lesions range from light brown to black in colour. Lesions may become darker if exposed to sunlight (UV rays).
Postinflammatory hyperpigmentation can occur in anyone, but is more common in darker skinned individuals, in whom the colour tends to be more intense and persists for a longer period.
What is the cause of postinflammatory hyperpigmentation?
Inflammatory responses of the skin to disease or trauma results in the release and oxidation of arachidonic acid. The resulting reaction alters the activity of immune cells and melanocytes. Melanocytes produce more melanin (skin colour pigment), which is transferred to surrounding skin cells. This is known as epidermal hypermelanosis and can be treated with skin care products.
What about marks caused by sun damage?
Larger flat brown spots on the face and hands arising in middle age also result from sun damage exposure. Unlike freckles they tend to persist for long periods and don't disappear in the winter (though they may fade). Commonly known as age spots or liver spots, the correct term for a single lesion is benign solar lentigo (plural lentigines). Lentigines are common in those with fair skin but are frequently seen in those who tan easily or have naturally dark skin. Lentigines are due to accumulated pigment cells (melanocytic hyperplasia).
What are the best non-surgical treatments for hyperpigmentation?
Usually, hyperpigmentation will gradually lessen over time and normal skin colour will return. However, this is a long process that may take up to 6-12 months or longer. It is advisable to use a good broad spectrum sunscreen daily to reduce further darkening. A variety of topical treatments are available to lighten and fade hyperpigmented lesions. Varying degrees of success are achieved but combinations of the treatments below are usually required for significant improvement.
- Stabilised Vitamin C : Water Soluble - Magnesium or Sodium Ascorbyl Phosphate (note: L-ascorbic acid, the type of vitamin C available in chemists, is very unstable once it is dissolved in water and is not suitable for water based cosmetics. It is also irritating to the skin due to its acidity)
- Stabilised Vitamin C: Oil soluble -Tetrahexyldecyl Ascorbate (note: Ascorbyl Palmitate, which is a cheap oil soluble vitamin C added to numerous cosmetics, is not suitable for treating hyperpigmentation. This is because it is impossible to dissolve enough of the active in a cosmetic formula to get significant results (it is used at less than 1% concentration). Tetrahexyldecyl Ascorbate is new oil soluble form of vitamin C developed in Japan, and is unique in that it can be used at concentrations of upto 7%. It is still fairly rare and expensive ingredient. but shows excellent skin benefit.
- Alpha Arbutin (This is a compound found in Bearberry. It is very stable and in my opinion the best active for melasma)
- Kojic acid (This is derived from reishi mushrooms. It works well, but will oxidise in water based creams, turning a brown colour)
- N-Acetyl Glucosamine & Niacinamide