Birthmarks: symptoms, causes & treatment

Birthmarks, called nevi in medical terms, are benign skin lesions that occur when pigment cells, known as melanocytes, accumulate at a specific spot in the skin. These melanocytes produce the brown pigment melanin, which is responsible for the color of your skin, hair, and eyes. When these cells start growing in clusters instead of staying evenly distributed, a mole is created.

It's a misconception that birthmarks are all congenital, despite the name. Some birthmarks are indeed present from birth, but most develop throughout childhood and adolescence. It is unusual for new birthmarks to develop after the age of 40. If new brown spots do appear later in life, it is important to have them checked.

The average number of moles varies widely between individuals. Most people have anywhere from 20 to 30 birthmarks, but some people have many more, sometimes hundreds. The number is influenced by hereditary factors and exposure to sunlight during your lifetime. Light-skinned people generally have more birthmarks than dark-skinned people.

It is important to distinguish moles from other brown spots on the skin. Freckles are not moles but accumulations of pigment without pigment cells. Age warts, also known as seborrheic keratoses, sometimes look like birthmarks but are thickenings of the outer layer of skin. These are completely benign but can be cosmetically disruptive.

Birthmarks are dynamic structures that change over the course of a lifetime. It is normal for moles to gradually grow, change color, or even disappear. These changes usually happen very slowly, over years. Rapid changes, on the other hand, are suspect and require medical assessment. Knowing your own birthmarks and checking them regularly is the best way to spot abnormal changes.

The development of birthmarks is determined by an interplay of hereditary factors and environmental influences, in particular exposure to sunlight. Hereditary predisposition plays an important role. If your parents have a lot of birthmarks, chances are you have them too. The tendency to develop atypical or dysplastic moles, which are slightly higher at risk of skin cancer, is also hereditary. This genetic component explains why some people have hundreds of birthmarks while others have only a handful.

Sun exposure is the most important environmental factor in the development of moles. In particular, repeated, intense sun exposure during childhood and adolescence contributes to the development of new birthmarks. UV radiation stimulates melanocytes to divide and can form clusters of these cells. This explains why people who have been out in the sun a lot have more birthmarks and why they are more common on parts of the body that are regularly exposed to the sun.

The mechanism behind formation starts at the cellular level. Normally, melanocytes are evenly distributed in the basal layer of the epidermis. When a mole develops, these cells begin to multiply and clump together. Initially, they remain in the epidermis, resulting in a flat mole. Later, the cells can migrate to deeper layers, resulting in a raised mole.

Hormonal changes during puberty and pregnancy can darken or make existing birthmarks grow. This is usually a normal, benign process. However, it is wise to have such changes checked, especially if they are rapid or have other suspicious features.

The transformation of a benign mole into malignant melanoma is a complex process driven by DNA damage in melanocytes. UV radiation is the main cause of this DNA damage. In most people, damaged cells are repaired or destroyed by the immune system. In some people, however, these damages accumulate and can derail cells and become cancerous. This process can take years to decades.

The risk of malignant transformation is not the same for all birthmarks. Dysplastic nevi, atypical birthmarks with irregular shape and color, have a slightly higher risk. Congenital birthmarks, especially large ones, are also at increased risk. The number of birthmarks also plays a role: people with more than 50 birthmarks have an increased risk of melanoma.

Birthmarks show a wide variation in appearance, but benign moles share certain common features that distinguish them from suspected lesions.

The shape of benign moles is typically symmetrical. If you draw an imaginary line through the middle, both halves are more or less identical. They can be round, oval, or regular in shape. The edges are sharply defined and clearly marked against the surrounding normal skin, with no outgrowths or irregular boundaries.

The size varies, but most are relatively small. Typical benign birthmarks are between 2 and 6 millimeters in diameter, smaller than the eraser at the end of a pencil. Birthmarks that are larger than 6 millimeters deserve extra attention. Very large congenital birthmarks can be several centimeters in size and require regular monitoring.

The color of benign moles is uniform across the entire injury. They can range from skin-colored to dark brown or almost black, but the color is evenly distributed. There are no zones of different shades within the same mole. Some birthmarks gradually fade over the years, which is a normal process.

The surface may be smooth and flat, or raised and knobby. Some moles are perfectly flat with the surrounding skin, while others stick out as tiny nodules. Thick, dark hairs can grow from raised birthmarks, which is completely normal. These hairs can be epilated or cut without problems. The surface is smooth and intact with no craters, scabs, or bleeding.

Suspicious features that may indicate malignant change are easy to remember with the ABCDE rule: Asymmetry where the two halves do not look alike, Bboundary where the edges are vague or irregular, Ccolor where multiple colors are present, Ddiameter greater than 6 millimetres, and Eevolution where the mole changes in size, shape, color, or thickness.

Additional warning signs include a mole that starts to itch, hurt, bleed, or develop a scab. A mole that is significantly different from your other birthmarks, the so-called ugly duckling, also deserves attention.

In principle, birthmarks can occur anywhere on the body, but are most frequent on parts of the body that are regularly exposed to the sun. The face, neck, shoulders, arms, and back often bear a significant number of birthmarks. The tops of the feet and the cleavage are also typical locations due to repeated sun exposure.

On the torso, birthmarks can occur anywhere. In people with many birthmarks, they are often more or less evenly distributed. The distribution varies on the limbs, with the outer sides of the arms that catch more sun often have more birthmarks than the inner sides.

In less exposed areas such as palms, soles and the scalp under the hair, birthmarks also occur, although less frequently. These birthmarks require extra attention because melanomas can be more aggressive in these locations. Birthmarks can also occur on intimate parts of the body. These areas are rarely investigated but do deserve attention in self-monitoring.

The treatment for birthmarks depends on several factors, including appearance, location, changes over time and your personal needs. Not all birthmarks require treatment.

Observation is the approach for the vast majority of birthmarks. Benign birthmarks that show no suspicious features do not need to be removed. Regular self-monitoring, about once every three months, is sufficient. In case of doubt or if changes occur, have the mole checked by your doctor or dermatologist. Photographing your birthmarks can help you notice subtle changes over time.

Birthmarks can be removed for cosmetic reasons or in case of regular irritation from clothing or jewelry. This decision will be made in consultation with your doctor, weighing the pros and cons of removal.

Diagnostic tests are necessary in the case of suspicious moles that meet the ABCDE criteria or show other warning signs. Your doctor will perform a skin biopsy, which will remove a sample of tissue for microscopic examination in the laboratory. Sometimes the entire mole is removed immediately as a precautionary measure. The pathologist determines whether there is a benign mole, an atypical mole or a malignant melanoma.

The method of removal depends on several factors. For superficial, clearly benign moles, shaving can be used, in which the mole is scraped away with a blade to the level of the surrounding skin. This method is quick and easy, but there is a small chance that the mole will partially grow back.

Excision is the method of choice for birthmarks that grow deeper into the skin or if malignancy is suspected. The doctor excises the entire mole including a border of healthy skin around it. This ensures that all cells are removed and reduces the risk of recurrence. The wound is closed with stitches. This method does produce a scar, the size of which depends on the size of the mole and its location.

In confirmed melanoma, extensive excision is necessary, removing a larger margin of healthy skin around it. The extent of this margin depends on the thickness of the melanoma. More advanced melanoma may also require research into metastases and additional treatment such as immunotherapy.

After removal, aftercare is important. Keep the wound clean and dry according to your doctor's instructions. Sutures are usually removed after 7 to 14 days, depending on location. The scar is initially red and raised but fades and flattens out over months to years. Protect the scar from sunlight to prevent pigmentation.

Follow-up after removal of atypical or malignant moles is essential. Your doctor will set a schedule for regular skin checks. In the case of melanoma, more intensive checks are necessary, initially every 3 to 6 months, later annually for life.

There are various misunderstandings and ineffective or dangerous approaches to birthmarks that you should avoid.

Self-removal of birthmarks is dangerous and strongly discouraged. Some people try to cut out, freeze, or burn away moles with chemicals. This can lead to serious infections, scarring, and may mask a malignant mole without removing it. If a mole is disturbed but not completely removed, this could potentially accelerate malignancy. Only have birthmarks removed by a doctor.

Over-the-counter creams and ointments that claim to bleach or remove birthmarks are ineffective for removing real birthmarks. These products may bleach the pigment on the surface, but do not remove melanocytes deep in the skin. They can be dangerous in malignant moles because they cosmetically disguise the problem without resolving it.

Natural remedies such as apple vinegar, garlic, or iodine that are touted online are not effective and can be harmful. These agents may cause chemical burns, scarring and pain. Rely on medically proven methods under professional guidance.

Ignoring changing birthmarks in the hope that it will go away on its own or because you're afraid of the rash is a dangerous strategy. Early detection of melanoma is crucial for a good prognosis. Early-stage melanoma is almost always curable with simple surgical removal. Delayed melanoma, on the other hand, can metastasize and become life-threatening.

Visiting the tanning bed to make moles fade or to “harden” the skin against the sun is a dangerous misunderstanding. Tanning beds actually increase the risk of skin cancer and accelerate skin aging. They offer no protection against natural sunlight. Avoid tanning beds and protect your skin from UV rays with clothing, shade and sunscreen.

‍Can a mole become malignant?

Yes, although fortunately this rarely happens, a benign mole can become malignant over time and turn into melanoma. This process is caused by the accumulation of DNA damage in the pigment cells, usually due to UV radiation. Most melanomas, however, do not develop from existing moles but develop new ones on normal skin. This underlines the importance of regularly checking your entire skin, not just existing moles.

How often should I check my birthmarks?

For most people without increased risk, self-monitoring once every three months is sufficient. Systematically check your entire body in a well-lit area with a large mirror and a hand mirror for hard-to-reach areas. Watch for new spots and changes in existing birthmarks. People with many birthmarks, atypical moles or a history of melanoma should have more frequent professional check-ups, usually once a year or more according to dermatologist advice.

Are birthmarks hereditary?

Having many birthmarks certainly has an inherited component. If your parents have a lot of birthmarks, chances are you have them too. The tendency to develop atypical birthmarks is also hereditary. This does not mean that all birthmarks are transmitted immediately, but it does mean that the predisposition to develop them is hereditary. The risk of melanoma is also partly hereditary, especially in families with multiple cases of skin cancer.

Can I have birthmarks removed just in case?

You can have cosmetically annoying moles removed, but removing all moles preventively is not useful or feasible. Most melanomas do not develop from existing moles but in new areas. In addition, the average person has dozens of birthmarks, which makes removing them all impractical. Targeted removal of suspicious or atypical birthmarks may, however, be useful after assessment by a specialist.

Do I need extra sun protection for my children?

Absolutely. Sun exposure during childhood is a major risk factor for developing melanoma later in life. Sunburn in childhood, in particular, increases the risk significantly. Protect children with clothing, hats, afternoon shade, and high-factor sunscreen. Teach kids the importance of sun protection early. This is one of the most effective ways to prevent skin cancer.

Does a changing mole always mean cancer?

No, not all changes in moles indicate cancer. Gradual, slow changes over years are often normal, especially during puberty, pregnancy, or aging. Birthmarks can slowly enlarge, change color, or even disappear. However, rapid changes over weeks to months, or changes that meet the ABCDE criteria, are suspicious and should always be evaluated by a physician. When in doubt, it is always wise to have an inspection carried out.

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