A number of conditions can cause changes in the pigmentation of the skin. Freckles are an obvious variation in pigmentation of the skin. This is caused not by uneven distribution of the cells that release the pigmentary changes, but by uneven release of the pigment. In the same way areas of pigment can be lost in a "white freckle" appearance or with larger problems such as those associated with vitiligo. Larger freckle-like lesions called lentigos can also arise usually indicating, like actinic bronzing, excessive sun exposure over time.
Then there are pigmentation changes associated with moles and other skin growths. Flat and raised mole areas that show changes in pigmentation need to be closely looked at to exclude more serious cancerous changes.
But the commonest, raised to near flat lesion that produces a brown pigmented appearance is the sometimes warty-looking seborrhoeic keratosis. This is completely benign but can appear unsightly at times.
A number of women have problems relating to hormone changes and sun exposure. With pregnancy, the oral contraceptive pill, or at times just due to body hormone fluctuations, exposure of the skin to the sun produces a patchy arrangement of pigmentation on the forehead, cheek and about the eyes. This chloasma or melasma effect will persist and can be difficult to get rid of.
Other inherited pigmentation areas such as “café-au-lait” lesions can be present in some people.
Moles And Other Skin Lesions
Appearance can be affected by various raised skin lesions. Although some people accept them as “beauty spots” their presence can be annoying in location or general appearance.
Moles, or naevi, are probably the most commonly recognised problem. They are genetically determined as far as occurrence goes. Usually we are not born with them but tend to acquire more as time goes by. By our late thirties or so we tend not to get any more. Colour may vary from flesh colour to dark brown. Most moles darken in colour in pregnancy. In spite of the common understanding that melanomas arise from moles only about 30% do so. Other melanomas arise from otherwise normal skin.
Skin tags commonly occur around the neck, under breasts and wherever a couple of skin layers move on each other. They can become larger over time and become annoying with catching on clothing and other items. At such times they can become temporarily swollen or enlarged. They are usually skin coloured. But at times they can be pigmented.
Seborrhoeic keratoses represent another genetically determined problem. Some people are much more likely to acquire them than others. They can be quite raised, or near flat. Their colour can vary from the same as skin, to some variation on brown, to almost black. Their surface tends to be a little rough or warty, hence their other name seborrhoeic warts.
If picked at or scratched they can fall off and the base bleed. Repeated local trauma such as rubbing can induce them to become bigger over time. Although they can appear very dark and worrisome at times, they do not become malignant or cancerous.
Warts are caused by a variety of viruses affecting the very surface of the skin. They represent an infection within the cells that grow rapidly as the virus assumes control. Originally it was thought there were about four different viruses. We now know there are many more. Over time we can build an immunity to them which causes the wart to disappear. As there is quite a number of different wart viruses we can acquire new ones after this.
As noted above this can be caused by a combination of sunlight exposure and hormone variation. This can occur in pregnancy, in which case it can at times settle once the pregnancy is over, although it may just lighten a bit. The oral contraceptive pill can provoke this effect as well. Sometimes changing your pill will help resolve it. At other times it can be just a body variation in hormone levels. People with more olive skin are more prone to this type of problem.
Treatment varies according to the problem. Some can be cut out and others cauterised (or burned). But there are other ways with lasers, and photodynamic therapy that can be very effective and leave smaller marks afterwards. See Dual Yellow laser, PDT.