What causes skin tags and moles?

Skin Tags

The medical term for skin tag is acrochordon. Other synonyms that have sometimes been used to refer to skin tags include soft warts, soft fibromas, fibroepithelial polyps (FEP), fibroma pendulans, and pedunculated fibroma. Skin tags can occur in anyone but tend to increase in frequency as we age. They are also more common in obese persons, possibly due to increased irritation and rubbing of skin folds. Hormonal factors or aging processes may also play a role in the development of skin tags.

Moles

The genes we inherit from our parents, along with our amount of sun exposure (especially during childhood) are major factors in determining mole numbers. Skin with more sun exposure tends to have more moles. However, moles may also occur in sun-protected areas.

Moles and freckles (medically termed ephelides) are darker than the surrounding skin. Moles may be raised or completely flat while freckles are always flat. Freckles and “sun spots” (medically termed lentigines) are due to an increase in the amount of dark pigment called melanin. Moles are more common in people prone to freckles. Freckles are flat spots that are tan, slightly reddish, or light-brown and typically appear during the sunny months. They frequently appear on people with light complexions. Many people with blond or red hair and green or blue eyes are more prone to these types of skin spots. Sun avoidance and sun protection, including the regular use of sunscreen may help to suppress the appearance of some types of moles and freckles.

Moles occur in all races (Caucasian, Asian, African, and Indian) and skin colors. Even animals have moles.

Moles may be present at birth or gradually appear later in the newborn period. Many children continue to develop moles through the teenage years and into young adulthood. Moles tend to grow very slightly in proportion to normal body growth. Congenital moles are those present at birth and so must have been present during fetal development. Other moles may arise later due to factors that are not genetic but environmental, such as sun exposure.

While many moles arise in the first years of life, the total number of moles typically peaks in the second or third decade of life to an average of 35. Most people do not develop new regular moles after the age of 30. Adults often develop non-mole growths like freckles, lentigines, “liver spots,” and seborrheic keratoses in later adulthood.

New moles appearing after age 35 may require close observation, medical evaluation, and possible biopsy. A brand-new mole in an adult may be a sign of an evolving abnormal mole or early melanoma. It is important to have any new or changing mole evaluated by a dermatologist.