Liver stains arise when certain skin cells, the so-called melanocytes, form the dye melanin. Melanin is also the substance that turns the skin brown after sunbathing. "A liver spot can be described as an unsuccessful attempt by the skin to protect itself from rays of light," says Christoffer Gebhardt from the Skin Cancer Center at the University Hospital Hamburg-Eppendorf.
Colors and shapes
Liver blotches are the most common benign changes in the skin, explains the expert. They appear in different colors - some are red-brown like the liver, some black-brown or brown-yellow, others bluish, if they are deeper in the skin. Only rarely does a mole become degenerated into a malignant lesion - but it can happen. Conspicuous stains are therefore a case for the dermatologist.
"Statistically, only one out of every ten thousandth liver spot develops malignant melanoma, which is a black skin cancer," explains Gebhardt. Rule of thumb: The more stains, the higher the risk of cancer. "Also, people in whose first-degree relationship - so parents or siblings - skin cancer occurred, have a significantly increased risk of developing skin cancer."
In Germany, around 21,000 people are diagnosed with black skin cancers every year, and men and women are equally affected. On average, those affected are 64 years old when they receive the diagnosis.
Liver spots are either present at birth or occur later. The exact cause of congenital moles is unclear. Acquired liver spots - those that occur only after birth or after the first two years of life - are the result of a combination of hereditary predisposition and UV radiation. Mostly this happens in childhood and adolescence. So-called age spots also result from increased exposure to UV light. People with lighter skin usually have more liver spots.
Freckles are not liver spots, but a separate category. "They are volatile changes in the uppermost layer of the skin," says Gebhardt. The effect of many freckles owners know: With the end of the summer, the points disappear again. Freckles are harmless, they do not cause skin cancer.
The ABCDE rule
Even to judge whether a liver spot is normal or not can be difficult. "The so-called ABCDE rule is an important tool for your own prevention and can help to estimate liver spots," says Katharina Schürings, Dermatologists in Dusseldorf.
A liver spot is examined for different characteristics:
- Is he asymmetrical ?
- Does he have an irregular limit ?
- Does he have a different color ? Because the more colors a skin has, the more suspicious it is. Is its diameter larger than six millimeters?
- Does it lift off the skin surface, so does it have an elevation ?
"Most of the time, they show a change in the skin's appearance, sometimes itching or sneezing, or scabbing," explains Schürings. Anyone who has identified a liver spot as conspicuous or has a skin mark where he is unsure should contact a dermatologist.
The statutory health insurance companies pay a skin cancer screening every two years for men and women over the age of 35 years. This includes a specific history and a visual whole body examination. Many insurance companies cover the costs of such a screening earlier. If there are indications of a disease in these examinations, these can generally be treated early and with good chances of recovery, explains the association of health insurances (GKV-Spitzenverband).
If a malignant change or skin cancer is suspected, the entire birthmark is surgically removed. It is also conceivable and possible to remove a birthmark for aesthetic reasons. Sometimes moles interfere because they are located in unfavorable places - for example under the bra or in the area of the trouser waistband. However, those affected should bear in mind that scars heal badly, especially in the middle of the body, warns dermatologist Schürings. The healing on the face, however, is usually very good. Important: The health insurance does not pay for the removal of such moles.
The biggest risk factor
"Our skin is sunbathing and light-addicted to work," says skin cancer specialist Gebhardt. "In our spare time and on vacation, many people leave their skin exposed to high doses of sunlight in the short term." The high-energy UV radiation can then destroy the genome of cells - from the healthy skin stem cell may then become a cancer stem cell. "In recent years, but the awareness of the dangers of excessive exposure to the sun and the importance of proper protection from the sun fortunately increased says Gebhardt.
The most effective way to prevent skin cancer is to protect yourself from the sun: wear long clothing, put on sunscreen, stay in the shade around lunchtime. "There is no healthy tanning," warns Schürings. "Tanning is always a protective mechanism of the skin."