Lentigines or age spots: what are they?

Lentigines, often called age spots, are pigmented lesions resulting from a localized dysregulation of skin pigmentation, the melanogenesis. Melanin, the pigment responsible for the skin’s natural coloration, is produced excessively in certain areas, leading to the appearance of visible brown spots.

Age spots develop as a consequence of cumulative sun exposure throughout life.

Solar lentigines typically emerge around age 50, but some may appear as early as age 40, particularly in fair-skinned individuals. With advancing age and repeated UV exposure, melanocyte function becomes disrupted: melanin production turns erratic, leading to the formation of spots on the most exposed areas, such as the face, hands, chest, shoulders, arms, or back.

These pigmented lesions are generally flat, small in size, and range from light brown to dark brown. Although lentigines are most often benign, some may progress to precancerous lesions known as Dubreuilh melanosis, or sometimes "malignant lentigo." This transformation is rare and slow, but it underscores the importance of a regular dermatological monitoring to monitor the evolution of lentigines, and, at the same time, that of moles.

To mitigate lentigines, cosmetic solutions are often the first resort. Some creams containing depigmenting agents, such as tranexamic acid or resveratrol, can help regulate melanin production and even out skin tone. These formulations work progressively and must be applied consistently to achieve visible results. It is important to note that this is not a miracle solution: while cosmetics can reduce the visibility of lentigines, they cannot eliminate them entirely.

On the dermatological side, chemical peels represent an effective option. TCA (trichloroacetic acid) peels or glycolic acid allow exfoliation of the skin’s superficial layer, promoting cellular turnover and reducing pigmented spots. Glycolic acid is also available over-the-counter, generally at lower concentrations (often between 5 and 10%), allowing for gentle at-home use without medical supervision.

A recent review assessed the efficacy and safety of trichloroacetic acid for the treatment of solar lentigines. The results, drawn from 13 studies, show that TCA improves the appearance of lesions in approximately 81% of cases. However, complete lesion clearance remains limited to about 25% of cases, which means that the treatment significantly improves the appearance of lentigines but does not always completely eliminate the lesions. Side effects, such as erythema or post-inflammatory hyperpigmentation, affect approximately 18% of patients and depend on TCA concentration, the number of sessions, and the skin phototype. Thus, while TCA is effective, it is not without risk.

Key figures on trichloroacetic acid peels for the treatment of solar lentigines:

Finally, laser therapy is effective for treating lentigines, especially those resistant to cosmetic treatments or chemical peels. Pigment-specific lasers, such as Nd:YAG or Q-switched lasers, selectively destroy excess pigment while preserving surrounding tissues. Sessions should be performed by an experienced dermatologist, and the number of passes depends on the depth and intensity of the lesions.

To prevent the appearance of lentigines, the primary strategy remains sun protection.

Indeed, UV rays stimulate melanocytes, the cells responsible for melanin production, which promotes the development of pigmented spots. It is therefore essential to apply a sunscreen every day, even when the sun isn’t very intense and not just before prolonged exposure. This protection should cover all exposed areas: face, neck, décolletage, but also the hands, which are often overlooked. The skin on the hands is particularly fragile and accumulates sun exposure over time, making it a high-risk area for the appearance of lentigines.

As a complement to sunscreen, certain measures can bolster prevention: wearing protective clothing, using hats or gloves during prolonged exposure, and avoiding at all costs artificial tanning. Additionally, adopting a skincare regimen that includes topical antioxidants, such as vitamin C or astaxanthin, can contribute to limiting oxidative stress and excessive melanin production.

• HUMBERT P. & al. Biological processes in solar lentigo: Insights brought by experimental models. Experimental Dermatology (2016).

• IMOKAWA G. & al. Melanocyte activation mechanisms and rational therapeutic treatments of solar lentigos. International Journal of Molecular Sciences (2019).

• MUNSHI M. & al. The efficacy and safety of trichloroacetic acid in the treatment of solar lentigo: A systematic review and meta-analysis. Archives of Dermatological Research (2025).

• ABDOLLAHIMAJD F. & al. Treatment of solar lentigines: A systematic review of clinical trials. Journal of Cosmetic Dermatology (2025).