Pigmented changes of the skin are divided into changes in the epidermis and the dermis, depending in which part of the skin they are located. Moles (nevi) are limited skin changes that occur due to a disruption in embryonic development, therefore, they can exist already at birth or can appear throughout life. They may be darker or lighter brown, black or blue. Sometimes they are at level, but can also be above the level of the skin. Their number can be various, but an adult on average has about twenty moles on their skin. The skin has the ability of self-protection from the negative effects of UV radiation that takes place using its own protective mechanisms. In the case when skin is exposed to the sun for too long and too often, the cells have damage and their own photo-protection is no longer enough and the mechanisms for renewing damaged cells become overloaded. Due to the excessive damage caused by the sun’s radiation, skin cells transfer wrong information and cause chronic damage to the skin. On the basis of appearance, the changes in the coloration of the skin can be diverse and we distinguish the following pigment changes:
Freckles appear in people of white skin and reddish hair in the form of small, brown changes on the level of the skin and are most often placed in the central part of the face, nose and cheeks. They can also appear on other parts of the skin that are often exposed to the sun such as the shoulders, upper back, neck, chest and hands. Their number and intensity is proportional to sun exposure. As a rule, they appear in childhood and they become the most prominent during the summer. Treatment is not necessary.
Solar lentigo (lentigo senilis)
Solar lentigo is a frequent change of the skin of older people, and occurs as a result of sun exposure. The changes are sized from few millimetres to one centimetre, can be lighter to darker brown in colour, they are in the level of the skin, and are always in places that are most exposed to the sun. They usually occur after 40 years of life, and with aging their number increases. These changes characteristically do not fade during seasons with less sunlight. Since these changes are directly associated with aging and long-lasting sun exposure, there are a number of synonyms in their name (senile lentigo or age spots).
Melasma is an acquired, symmetric change on the face of the lighter or darker brown colour. It can be associated with the many etiologic factors such as pregnancy, endocrine disorders, the use of some medications, and one of the main reasons for the emergence is sun exposure.