New moles on my skin Why do they appear?

The appearance of new moles on our skin is a very frequent and normal phenomenon.. The technical name of a mole is nevus and comes from Latin meaning birthmark, however most of them appear in adolescence and adulthood. But not all new lesions that appear on our skin are moles and it is important to know the differences and the most frequent causes. 

So, are all new skin lesions moles?

No, not all the spots that appear on the skin are moles. In my practice I see many, many types of skin lesions that look very similar to moles, but after examining them in detail I make a different diagnosis. 

Among the most frequent diagnoses that I see in my office when my patients ask me about the appearance of new moles are:

  • Benign solar lentigines
  • Seborrheic keratoses
  • Fibromas or acrochordons 
  • red polka dots
  • Melanocytic nevus
In addition, to further refine the diagnosis we have to think about the patient's ageThere will be injuries that are more specific to one age group or another. Together with the physical examination and knowing the age of presentation of the new moles we will be able to establish a more accurate diagnosis. 
Infographic showing how the appearance of many moles depends on age.

In this informative infographic I show you the most common causes of new skin lesions grouped by age. But in reality there are many more causes that only dermatologists are qualified to evaluate them. 

How to establish the diagnosis of new moles?

Dermatoscope used for early skin cancer detection

Every time I see a patient with a new mole, I explain the importance of a proper diagnosis. To this end, dermatologists we use dermoscopy to make more accurate diagnoses. 

Therefore, when new moles appear on the skin, a visit to your favorite dermatologist is always recommended.

1- Melanocytic moles or nevus

The appearance of melanocytic moles is a very frequent phenomenon during adolescence and young adulthood. Nevi are proliferations of melanocytes, which are the cells responsible for coloring our skin. Normally we differentiate moles into 2 types depending on the depth they are located in our skin. 

  • Joint nevus: correspond to flat moles and are usually light brown to black in color. They are benign and remain stable over time.
  • Dermal nevusDermal or warty moles (because of their shape), on the other hand, are those that have relief. They are also known as flesh moles. These moles tend to protrude over time and lose their pigment. 
  • Other melanocytic nevi: there are many more types of moles. If you are interested in knowing them what types of melanocytic nevus exist you can see them here
Here are some pictures so that you can see the different types of moles that are most common. 

Joint nevus

Junctional nevus on photodamaged skin

Dermal nevus

Mole removal on the face

Why do I get new moles?

Different studies have shown that in most cases it is an interaction of multiple genetic factors associated with sun exposure that triggers the appearance of the same. Lhe good news is that almost all moles are benign. 

On the contrary, if new moles appear in an adult, they are more likely to become cancerous than those we have had all our lives. If you have new moles after the age of 40 it could be a malignant skin lesion. 

Is it normal if I have many new moles?

Having some moles on our body is perfectly normal. But if we have lots and lots of moles and some of them have atypical characteristics, you may have a increased risk of developing melanoma during your lifetime. 

Back of a patient with dysplastic nevus syndrome with many new moles.

That is why in cases of patients with many nevi and/or atypical nevi we recommend a follow-up with a dermatologist. Below is a picture of a patient who has a dysplastic nevus syndrome. This means that she has more than 100 moles and some of them with clinically atypical features (ABCDE rule). 

2- Solar lentils

A lentigo (plural: lentigines) is a spot on the skin without relief that is darker (usually brown) than the surrounding skin. Lentigines are more common among Caucasians, especially fair-skinned people.

The sun exposure that we accumulate during our lives is the main cause of these lentigines. This is why they usually appear after the age of 30 and appear on the parts of the body that receive the most sun, such as the face, décolleté and hands. Some lentigines may be caused by the following factors genetic (family history) or by medical procedures, such as radiotherapy

Woman with many sun spots on her face

Lentigines are not malignant, however if they are not evaluated by dermatologists who are experts in dermatoscopy they can easily be confused with other moles or even skin cancer. We usually treat them for cosmetic reasons and if you are interested in knowing more about it you can continue reading my post on how to remove spots on the face? 

3- Seborrheic keratoses

Seborrheic keratoses are brown or black proliferations that usually appear on the face, chest and back. They originate from cells called keratinocytes. As they develop, seborrheic keratoses take on a warty appearance so the main reason for consultation is usually cosmetic. 

Do I need to treat seborrheic keratoses?

The good news is that seborrheic keratoses are not cancerous and are not contagious. Therefore, there is no need to treat them.

If you decide to remove seborrheic keratoses because you do not like their appearance or because they are chronically irritated by clothing they can be effectively removed by a specialist. Common methods to remove these lesions include laser, cryosurgery and electrosurgery.

4- Fibromas or acrochordons

A cutaneous fibroid or acrochordon is a small flap of tissue that hangs from the skin by a connecting stalk. Cutaneous fibroids are not dangerous and should not be confused with papillomas or warts, which are contagious. 

They usually appear on the neck, chest, back, armpits, under the breasts or in the groin area. Cutaneous fibroids appear more frequently in women, especially with weight gain, and in older people.

Cutaneous fibroids do not usually cause pain. However, they can become irritated if something, such as clothing, jewelry or skin, rubs against them. Also, I get many people in the office who do not like these lesions and we end up removing them for cosmetic reasons. If you want to removing fibroids is always important to be performed by an expert. and with safe, non-marking methods.  

Many fibroids or acrochordons in the neck

5- Angiomas

Cutaneous angiomas are very common lesions that can develop on almost any part of the body. They are also known as senile angiomas or ruby spots. They usually appear after the age of 30 and their cause seems to be mainly genetic. 


Detail of red moles or red dots on the skin of an elderly patient with photodamage.

This skin lesion is usually not a cause for concern unless it bleeds frequently or changes in size, shape or color. Consult your dermatologist if you notice any of these symptoms as they could be indicative of malignancy. In the following article you can find all the information regarding angiomas and how you can remove them. 

So what do I do if I have a lot of new moles?

Regardless of your age, it is important that if you have many new brown moles, you consult your dermatologist for a complete examination so that we can establish a correct diagnosis. 

Depending on the cause, your dermatologist may recommend specific mole follow-up or in some cases mole removal. 


In this post I talked about all those multiple skin lesions that appear more or less quickly. If you have any of the following symptoms I recommend you to read the related posts:

  1. I only have a mole that has changed my shape 
  2. It has appeared to me a mole that I don't like
  3. I have had a lot of spots on the face
  4. I have many red dots on my skin

References from the new polka dots post

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Sebastian Podlipnik - Skin cancer

Sebastian Podlipnik

Dermatology Blog

I am a dermatologist and cum laude MD and author of multiple research studies. I specialize in skin cancer, laser technologies and cosmetic dermatology. The intention of this blog is to bring you closer to topics of interest in dermatology and research.

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