Simple freckles are small and fairly light in color.
The appearance of dark freckles on the surface of the skin can occur for various reasons. Common culprits include lifelong overexposure to the sun, a genetic predisposition to freckles, and a combination of both. Occasionally, diseases can also cause dark spots to appear on the skin. One example is melanoma, a serious form of skin cancer, and another is xeroderma pigmentosum, a relatively rare disorder in which patients are unusually sensitive to all sources of ultraviolet light. In almost all cases, freckles or dark spots are benign in nature and do not pose a serious health threat.
Using sunscreen, sunglasses, and other protective gear can help fair-skinned people reduce the risk of skin melanomas.
The main scientific cause of dark freckles and increased skin pigmentation is the presence of epidermal cells called melanocytes. As the skin is exposed to ultraviolet light, melanocytes try to protect the inner layers of the skin by producing the pigment melanin, which better absorbs ultraviolet rays and helps prevent further damage to the deep epidermis. People who can produce a lot of melanin tend to have darker skin, fewer freckles, and don’t burn as easily. In other people, the melanin occurs in small clusters, resulting in more freckles than in people with darker skin. These freckles can range in color from light tan to dark brown, or even reddish in some cases.
Adults who have suffered severe sunburn in their life will be more likely to have dark freckles.
Sunburn freckles and simple freckles are the two most common types of freckles. Simple freckles usually appear during childhood and are small and fairly light in color; they can be genetically transmitted or occur from normal sun exposure, especially in people with fair skin. Sunburned freckles are darker, larger, and may have jagged edges. These types of skin blemishes are usually caused by frequent sunburn and most often appear on the arms, back, and shoulders. Both types of freckles appear most often during sunny summer weather and may fade during the winter months.
People with fair skin can develop freckles.
The plural term lentigines refers to dark freckles that develop over time and do not go away. Although freckles are darker than normal in color, lentigines are normal and usually do not indicate a health threat. As they approach middle age, adults who have suffered severe sunburn and excessive UV exposure throughout their lives may develop lentigines and seborrheic keratoses. These keratoses are rough, raised patches of skin that can range in color from light brown to black. Like other skin discolorations, seborrheic keratoses are usually benign and do not pose serious health risks.