A birthmark is a visible mark on the skin present at birth or developing shortly afterward. These marks vary in color, size, and texture, appearing as flat areas or raised spots. While the term “birthmark” suggests presence from birth, many people notice new skin marks as they age. True birthmarks are congenital, forming during fetal development or appearing within the first few weeks of life. Other skin marks, not considered true birthmarks, often emerge later in adulthood.
Understanding True Birthmarks
Medically, a true birthmark is a skin irregularity present at birth or visible soon after, usually within the first month. These marks arise from imbalances in the development of skin cells or blood vessels. Birthmarks are broadly categorized into two main types: vascular and pigmented.
Vascular birthmarks result from blood vessels that did not form as expected during fetal development. Examples include hemangiomas, often called “strawberry marks,” which are red and can appear weeks after birth, growing rapidly before fading. Port-wine stains are another type, appearing as flat, pink to dark red or purple patches that may darken and thicken over time. Pigmented birthmarks form from clusters of melanocyte cells, responsible for skin color. These include café-au-lait spots, light brown patches, and congenital moles (nevi), moles present from birth.
Common Skin Marks That Appear Later in Life
Many common skin lesions develop in adulthood and are often mistaken for “new birthmarks.” Moles, medically known as acquired nevi, frequently develop during childhood and adolescence, though they can also appear in adulthood. They are typically uniform in shape and color, often triggered by sun exposure or hormonal changes.
Age spots, also called solar lentigines or liver spots, are flat, brown, or tan patches that typically emerge on sun-exposed areas like the face, hands, and shoulders. They result from prolonged ultraviolet (UV) radiation exposure. Seborrheic keratoses are waxy, “stuck-on” lesions that can be tan, brown, or black, often becoming more numerous with age, especially after 40. Cherry angiomas are small, bright red or purplish bumps of tiny blood vessels, frequently appearing after age 30 and increasing with age. Skin tags, or acrochordons, are small, soft, flesh-colored growths that hang off the skin, commonly found in areas where skin rubs, such as the neck, armpits, and groin.
Factors Contributing to New Skin Marks
New skin marks later in life are influenced by aging and environmental exposure. Sun exposure is a significant contributor, particularly for pigmented lesions like age spots. UV light speeds up melanin production, and years of sun exposure can cause melanin to clump, leading to darker spots.
The natural aging process also plays a role, as skin undergoes cellular changes and decreased elasticity. This contributes to the development of benign growths, including seborrheic keratoses, which become more common with age. Genetics influence an individual’s predisposition to moles or skin growths; a family history increases likelihood. Hormonal changes, such as those during pregnancy or menopause, can also influence the appearance of marks like moles, age spots, and cherry angiomas due to their effect on melanin production or blood vessel formation.
When to Seek Medical Advice
While many new skin marks are harmless, monitor them for changes that might suggest a more serious condition. Any new or evolving skin lesion warrants medical attention from a dermatologist. Early detection is important for treating skin conditions, including skin cancers.
Healthcare providers recommend using the “ABCDEs” as a guide to identify suspicious moles or lesions:
- A: Asymmetry, where one half of the spot does not match the other.
- B: Border irregularity, where the edges are ragged, notched, or blurred.
- C: Color variation, indicating multiple shades of brown, black, or areas of red, white, or blue within the same spot.
- D: Diameter, noting that melanomas are often larger than 6 millimeters (about the size of a pencil eraser).
- E: Evolving, meaning any change in size, shape, color, or texture of a mole, or new symptoms like itching or bleeding.
If any of these signs are present, consult a healthcare provider without delay.