Melasma is the most Common Cause of Facial Hyperpigmentation
London Dermatology | 3 August 2024
Melasma (also known as chloasma) is a smudgy pigmentation which characteristically affects the face of young adults. Melasma is different from tanning even though both are caused by sunshine.
A tan accumulates in days and lasts weeks. Melasma accumulates in minutes and lasts months.
Dropping your guard, even for a few minutes, allows melasma to accumulate. To avoid melasma it is therefore necessary to be religiously strict in avoiding the sun.
Melasma is exquisitely sensitive to sunlight and, in contrast to sunburn or suntan, melasma can develop even when the sun is low in the sky.
Therefore, when driving in the early morning or late afternoon the sun shining through the car window may worsen melasma. Other sources of ultraviolet light, including fluorescent strip lighting, can also aggravate melasma. Tannable skin is particularly susceptible to melasma.
Vulnerability to melasma pigmentation is greater if light strikes when the skin is red for any reason. This is because redness means increased blood flow. Blood carries heat and oxygen. Heat and oxygen non-specifically accelerate any chemical reaction, including the light dependent chemical reaction that is responsible for melasma pigmentation. Thus, melasma pigmentation is most easily acquired when tannable skin is exposed to strong sunlight whilst at the same time being red for any cause. Internal causes of redness include heat, alcohol, spicy food, exercise, stress, anaemia, weight and especially hormones (premenstrual, pregnancy, the pill and thyroid disorders). External causes of redness include any agent that would sting were it to make contact with the whites of the eyes, “the eyeball rule”. These include friction, scent, aftershaves and some cosmetics. Waxing or threading of facial hair should also been avoided in the seven days preceding any sunny holidays.
Fortunately, the body has a natural mechanism to clear melasma pigmentation. This occurs at a slow and steady rate. This natural process will clear melasma from the face of most patients within five or six months, so long as the formation of new melasma pigmentation can be absolutely avoided. Therefore, the most important step in treatment is to avoid the formation of any new pigment by absolutely strict protection from sunlight and other sources of ultraviolet light. Therefore:
1. Seek the shade.
2. Wear sunscreen every day, even in winter. The best sunscreens for melasma should offer protection against UVB, UVA and also the shorter wavelengths of visible light. (The SPF number is a measure of the protection against UVB rays. The stars are a measure of the protection against UVA rays. Protection against visible light is also required in melasma prevention.) Suitable sunscreens for melasma are:
Bioderma Photoderm SPF 50+, La Roche Posay Anthelios XL SPF 50+, Depiwhite M SPF 50+.
3. On sunny winter days, sunscreen should be applied three times a day.
4. In strong sunlight, sunscreens need to be reapplied every 80 minutes. Don’t forget to reapply sunscreen to your lips after eating and to your hands after hand washing!
5. Sunglasses and a wide brimmed hat or head scarf are advisable when outside.
6. Protect your neck, chin and upper lip from the sun also.
7. Be in the shade when in the car.
Heat and oxygen non-specifically accelerate any chemical reaction. Just as they accelerate the light dependant accumulation of melasma pigmentation by day, so will they also accelerate the natural pigment clearance mechanism which occurs by night. Therefore, it is logical not only to try to avoid becoming red in the day (especially when the sun is strong) but also to try to increase blood flow by night. Blood flow at night can be encouraged by the application of certain creams. These night depigmenting creams must be used very sparingly. If the night depigmenting creams are applied too generously, the skin will remain pink in the morning which would then be counterproductive.