Understanding Solar Lentigo: Causes and Treatment Options

London Dermatology | 8 June 2025

Solar lentigo is a harmless dark spot that appears on the skin due to long-term exposure to ultraviolet (UV) light. This type of pigmentation occurs when melanocytes, the cells responsible for producing pigment, multiply in certain areas and cause melanin to accumulate within the skin’s outer layer.

Also referred to as sun spots, liver spots, or age spots, solar lentigines are very common, especially in individuals over the age of 40. They are also sometimes called senile freckles or old age spots.

A solar lentigo typically appears as a flat, well-defined patch on the skin. Its shape may be round, oval, or irregular, and its colour can vary from tan to dark brown or even black. Some have a slightly scaly texture. These marks can range in size from a few millimetres to several centimetres. They usually appear in clusters on sun-exposed areas such as the face, shoulders, arms, and the backs of the hands. Although they can develop in people with any skin tone, they are more common in those with fair skin.

Diagnosis is usually made based on appearance. In some cases, however, solar lentigo may resemble a melanoma, a serious form of skin cancer. When the pigmentation has an irregular shape or colour, it may be described as an atypical solar lentigo. A dermatoscopic examination can help confirm the diagnosis, but if uncertainty remains, a skin biopsy may be recommended to rule out other conditions.

Solar lentigines can sometimes develop into seborrhoeic keratoses, which are benign, wart-like skin growths. In other cases, inflammation may occur in the lesion, leading to what is called a lichen-planus-like keratosis, also known as a lichenoid keratosis. These lesions often resolve over time without intervention.

If left untreated, solar lentigines are generally permanent. However, a number of treatments are available:

• Cryotherapy, which involves freezing the spot with a cold spray

• Laser therapy, used to break up pigmentation

• Cysteamine cream, which can reduce excess pigmentation over time

Hydroquinone and other bleaching creams have shown limited success in treating solar lentigo. Cryotherapy and laser treatments may occasionally leave dark or light marks, which may be temporary or, in some cases, permanent.

Preventing solar lentigo begins with sun protection early in life. Regular use of sunscreen and minimising exposure to direct sunlight remain the most effective ways to prevent the development of new spots.

If you are concerned about sun spots or want to explore your treatment options, contact Devonshire Dermatology to arrange a consultation with one of our specialists.