Hyperpigmentation

Age spots

Age spots, also known as solar lentigines or liver spots, are one of the most recognizable types of brown spots. They typically appear as flat, well-defined patches that range in color from light tan to dark brown. Despite the name “age spots,” they are not caused by aging itself but by years of sun exposure. They are most often found on areas that receive chronic sunlight, including the face, neck, chest, shoulders, forearms, and backs of the hands.

Seborrheic keratoses

Seborrheic keratoses are very common, benign skin growths that often appear as waxy, “stuck-on” plaques in older adults. They are typically brown but can also be skin-colored. Over time, they may progress from being relatively flat to more raised, warty or scaly.

Hyperpigmentation

Hyperpigmentation is a broader medical term that refers to any condition in which patches of skin become darker than the surrounding area. It includes age spots but also encompasses other pigment disorders such as melasma and post-inflammatory hyperpigmentation. Hyperpigmented areas may be small and isolated or more widespread, depending on the underlying cause.

Whereas seborrheic keratoses are a common sign of skin aging, the most significant contributor to lentigo formation is ultraviolet radiation from the sun. Repeated sun exposure stimulates melanocytes to produce more pigment as a protective response. Over time, this process can lead to localized clusters of excess melanin, resulting in visible spots. Even brief daily exposure accumulates over decades, which explains why these changes often appear later in life.

Artificial sources of ultraviolet light, such as tanning beds, also increase the risk of developing pigmented lesions. Individuals with lighter skin tones may notice these changes earlier because there is less natural melanin protection, but people of all skin types can develop sun-related pigmentation.

Conditions that lead to hyperpigmentation such as melasma are associated with hormonal fluctuations, including pregnancy and the use of certain contraceptives. In these cases, pigment tends to appear in larger, symmetrical patches, often across the cheeks, forehead, or upper lip.

Inflammation within the skin can also lead to hyperpigmentation. Acne, eczema, rashes, cuts, and even cosmetic procedures may leave behind darkened areas after healing. This process, known as post-inflammatory hyperpigmentation, occurs when inflammation stimulates melanocytes to increase pigment production during recovery. It is particularly common in individuals with medium to darker skin tones.

Less commonly, certain medications or underlying medical conditions may contribute to changes in skin pigmentation. When pigment changes are widespread, sudden, or accompanied by other symptoms, a thorough evaluation is essential.

Seborrheic keratoses are mostly asymptomatic but can become irritated or itchy, especially with any friction from clothing. Age spots usually appear as flat, oval or round lesions with clearly defined borders. They tend to remain stable in size but may gradually darken over time with continued sun exposure. They are not raised and do not bleed.

In contrast, post-inflammatory hyperpigmentation often follows an identifiable skin event, such as a breakout or rash. The affected area may initially have been red or irritated before transitioning to a darker shade as it healed.

It is important to distinguish benign brown spots from potentially dangerous lesions. Concerning features include rapid growth, irregular or poorly defined borders, multiple colors within a single spot, bleeding, crusting, or a change in shape or texture. These characteristics may signal skin cancer and should never be ignored.

Diagnosis begins with a detailed history and thorough skin examination. During a consultation with Dr. Patricia Richey, attention is given to when the spot first appeared, whether it has changed, and any associated symptoms. A history of sun exposure, tanning bed use, hormonal changes, or prior skin inflammation provides valuable context.

A visual examination often allows an experienced dermatologist to distinguish between common age spots and other pigmented lesions. A dermatoscope, a specialized handheld device that magnifies and illuminates the skin, may be used to evaluate pigment patterns and structures beneath the surface. This tool helps differentiate benign lesions from suspicious growths.

If a spot has atypical features or raises concern for malignancy, a skin biopsy may be recommended. In this procedure, a small sample of tissue is removed under local anesthesia and sent to a laboratory for microscopic evaluation. A biopsy provides definitive information and is essential when ruling out melanoma or other forms of skin cancer.

Patients should be familiar with the warning signs of melanoma, often summarized by the ABCDE criteria: asymmetry, border irregularity, color variation, diameter greater than six millimeters, and evolving appearance. Any pigmented lesion demonstrating these characteristics warrants prompt evaluation.

In most cases, brown spots and age spots are benign and related to cumulative sun exposure. However, accurate diagnosis is critical because early skin cancers can sometimes resemble harmless pigment changes.