Lentigines or age spots: what are they?

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

Age spots result from the accumulation of sun exposure over the course of a lifetime.

Solar lentigines typically appear around the age of 50, but some may manifest as early as 40, particularly in individuals with fair skin. With advancing age and regular UV radiation exposure, melanocyte function becomes disrupted: their melanin production turns chaotic, leading to the emergence of spots on the most exposed areas, such as the face, hands, décolletage, shoulders, arms or back.

These pigmented spots 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 highlights the importance of a regular dermatological monitoring to monitor the progression of lentigines, and, at the same time, that of moles.

To reduce lentigines, cosmetic solutions are often the first port of call. Some creams containing depigmenting agents, such as the tranexamic acid or the resveratrol, can help regulate melanin production and even out skin tone. These formulations act gradually and must be applied regularly to achieve visible results. It should be noted that this is not a miracle cure: while cosmetics can diminish the visibility of lentigines, they cannot eliminate them entirely.

In terms of dermatological approaches, chemical peels represent an effective option. Peels with TCA (trichloroacetic acid) or glycolic acid enable exfoliation of the skin’s superficial layer, promoting cellular renewal and diminishing pigmented spots. Glycolic acid is also available over the counter, usually at lower concentrations (often between 5% and 10%), allowing for gentle at-home use without medical supervision.

A recent review evaluated the efficacy and safety of trichloroacetic acid for the treatment of solar lentigines. The results, based on 13 studies, show that TCA improves the appearance of lesions in approximately 81% of cases. However, complete clearance of spots remains limited to approximately 25% of cases, which means that the treatment significantly improves the appearance of lentigines but does not always fully 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, particularly those resistant to cosmetic treatments or chemical peels. Pigment-specific lasers, such as Nd:YAG or Q-switched, selectively destroy excess pigments while preserving surrounding tissues. Sessions should be conducted by an experienced dermatologist, and the number of passes depends on the depth and intensity of the lesions.

To prevent the onset of solar lentigines, the first step remains sun protection.

Indeed, UV rays stimulate melanocytes, the cells responsible for melanin production, which promotes the emergence of pigmented spots. It is therefore essential to apply a sunscreen every day, even when the sun is not particularly strong, and not only before extended exposure. This protection should cover all exposed areas: face, neck, décolletage, but also the hands, which are often neglected. The skin on the hands is particularly delicate and cumulative in its sun exposure, making them a high-risk area for the development of lentigines.

In addition to suncream, certain measures can strengthen prevention: wearing full-coverage clothing, using hats or gloves during prolonged exposure, and avoiding at all costs artificial tanning. Furthermore, adopting a skincare regimen that includes topical antioxidants, such as vitamin C or astaxanthin, can help limit 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).