What causes moles and how can they be monitored?

What are moles?

Moles, also known as nevi, are pigmented formations on the skin resulting from the growth of pigment cells called melanocytes.

These cutaneous melanocytes produce a pigment called melanin, responsible for the color of skin, hair and eyes. Moles can vary in size, color and shape from round to oval, but they are generally brown or black spots that appear on the surface of the skin.

 

What causes moles?

Most moles form during a person's lifetime, often as a result of exposure to the sun's ultraviolet(UV) rays. UV rays can stimulate the production of melanin, causing these small spots to appear on the skin. However, it's important to note that some moles can also be present at birth and are inherited genetically.

Congenital moles, also known as congenital nevi, are present from birth or appear shortly afterwards. They are not directly linked to UV exposure, as melanin, the pigment responsible for skin color, is already present in the newborn.

Heredity plays an important role in the formation of congenital moles. If parents have moles, their children are more likely to be born with them. However, while heredity can influence the presence of moles, other complex genetic factors are also involved in their development.

In general, moles are considered benign skin formations and require no special treatment. However, it is crucial to monitor their evolution for any potential signs of skin cancer, especially melanoma.

How to monitor moles and how to recognise a worrying mole?

Regular monitoring of moles is recommended to detect any changes. In case of doubt, it's essential to screen and consult dermatologists. Vigilance is particularly important in the presence of atypical moles, characterized by irregular edges, uneven color or unusual size.

The ABCDE method is often used to assess the dangerousness of a mole:

• Asymmetry: Normal moles are generally symmetrical. Any asymmetry should be carefully examined.
• Edges: Regular edges are normal, but irregular edges may indicate a problem.
• Color: A uniform brown color is usual. Color variations may indicate a problem.
• Diameter: Normal moles are generally less than 6 millimeters in diameter.
• Evolution: Any change in the size, shape, color or texture of the mole should be reported.

 

Risk factors for the development of atypical moles

Atypical moles, also known as dysplastic nevi, are moles that have unusual characteristics compared to normal moles. Certain risk factors may contribute to this 

• Family history: People with a family history of melanoma or atypical moles have an increased risk of developing atypical moles. Genetic factors may play a role in predisposition to these types of moles.
• UV exposure: Although not all moles are directly linked to sun exposure, UV rays can contribute to the development of atypical moles. Excessive sun exposure, particularly during childhood and adolescence, is a risk factor.
• Skin phototype: Fair-skinned individuals are generally more likely to develop atypical moles. People with fair skin and blond or red hair have less melanin to protect the skin from UV damage.
• Personal history of sunburn: Repeated sunburn, particularly during childhood, can increase the risk of developing atypical moles. Inadequate sun protection also contributes to this risk.
• Total number of moles: People with a large number of moles have a potentially higher risk of developing atypical moles. However, the sheer number of moles is not the only indicator of risk.
• Hormonal factors: Certain hormonal changes, such as those occurring during pregnancy, can influence the development of atypical moles.
• Age: Atypical moles tend to appear in the teens and twenties. However, they can develop at any age.

It's essential to note that while these factors may increase risk, their presence does not necessarily guarantee the development of atypical moles. Regular skin monitoring, recognizing signs of atypia, and consulting a dermatologist when in doubt are important practices for detecting and treating any problems early.

 

Monitoring moles on the scalp

Moles can appear on any part of the body, including the scalp. Due to the presence of hair, it can be more difficult to detect changes on the scalp. However, it is essential to monitor this area regularly, especially ifexposure to the sun is frequent. Mirrors and hairdressers can help monitor moles on the scalp.

How to prevent the appearance of moles

Although some factors linked to mole formation, such as family history and genetics, are uncontrollable, there are preventive measures you can take to reduce the risk of new moles appearing and minimize the risks associated with these skin formations. Here are a few tips on how to prevent the appearance of moles:

• Sun protection: Exposure to the sun's ultraviolet (UV) rays is one of the main factors contributing to the formation of moles. Use a high SPF sunscreen regularly, even on cloudy days, and avoid excessive exposure to the sun.
• Avoid sunburn: Frequent sunburn, especially during childhood, increases the risk of developing atypical moles. Protect yourself from the sun by using protective clothing, hats and seeking shade during the hottest hours of the day.
• Regular monitoring: Check your skin regularly for any changes in the size, color, shape or texture of existing moles. Pay particular attention to atypical moles, and consult a dermatologist if in doubt.
• Protective clothing: Wear clothing that covers your skin, especially on hot, sunny days. Opt for wide-brimmed hats, sunglasses and long-sleeved clothing to minimize sun exposure.
• Avoid tanning beds: Tanning beds can also contribute to UV damage. Avoid the use of tanning beds to reduce the risk of atypical mole formation.
• Balanced diet: Certain nutrients, such as the antioxidants found in fruit and vegetables, can contribute to skin health. Adopt a balanced diet to promote healthy skin.
• Stress management: Chronic stress can affect skin health. Adopt stress management strategies, such as meditation, yoga or other relaxing activities.
• Regular consultations with a dermatologist: Regular consultations with a dermatologist can help monitor your skin professionally. They can detect and assess atypical moles, provide personalized preventive advice and recommend appropriate measures when needed.

It's important to note that even by taking these preventive measures, it's not possible to completely eliminate the risk of new moles forming. However, these tips can help minimize the risk and maintain healthy skin. If in doubt, or if you notice any suspicious changes on your skin, always consult a health professional.

What is melanoma?

Melanoma is a rare skin cancer, but one of the fastest-growing in terms of the number of new cases each year. It is also one of the leading causes of cancer in young people (affected patients are often aged between 25 and 35).

Melanoma is the uncontrolled multiplication of melanocytes (melanin-producing skin cells) that have become cancerous. The tumor usually remains localized in theepidermis.

If melanoma is not treated early, it can metastasize and spread to other organs. This may justify treatment with chemotherapy, but this is always determined by your doctor.

The risk of developing skin melanoma is higher if you don't take into account the elements we've mentioned in terms of prevention.

Sources

• Heistein JB, Acharya U, Mukkamalla SKR. Malignant Melanoma. 2023 May 22. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. PMID: 29262210.
• Davis LE, Shalin SC, Tackett AJ. Current state of melanoma diagnosis and treatment. Cancer Biol Ther. 2019;20(11):1366-1379. doi: 10.1080/15384047.2019.1640032. Epub 2019 Aug 1. PMID: 31366280; PMCID: PMC6804807.