What is the diagnosis and treatment for solar lentigo (actinic lentigo)?

From the Guidelines

Solar lentigo is a benign condition that can be managed with topical treatments and preventive measures, and patients with concerns about their skin lesions should be evaluated by a healthcare provider to rule out skin cancer. When considering the management of solar lentigo, it is essential to prioritize prevention and early detection of skin cancer, as actinic keratosis (AK) and other forms of actinic damage can increase the risk of developing skin cancer 1. Some key points to consider in the management of solar lentigo include:

• Topical retinoids, hydroquinone, and azelaic acid can be effective treatments for solar lentigo
• Prevention is crucial and involves daily application of broad-spectrum sunscreen with SPF 30 or higher, wearing protective clothing, and avoiding peak sun hours
• Any spot that changes in size, shape, color, or becomes painful should be evaluated by a healthcare provider to rule out skin cancer
• Consider referral for specialist care when lesions are likely to be AK, but there is concern that they might be SCC, for example when they are bleeding, painful, or thickened with substance when held between finger and thumb 1. In terms of specific treatment options, topical retinoids like tretinoin 0.025-0.1% applied nightly can promote cell turnover and improve the appearance of solar lentigines. Additionally, hydroquinone 2-4% cream applied twice daily for 8-12 weeks can inhibit melanin production and reduce the appearance of solar lentigines. It is also important to note that prevention is key, and daily application of broad-spectrum sunscreen with SPF 30 or higher, wearing protective clothing, and avoiding peak sun hours can help prevent the development of new solar lentigines. Overall, the management of solar lentigo should prioritize prevention, early detection, and effective treatment to improve patient outcomes and reduce the risk of skin cancer.

From the Research

Definition and Characteristics of Solar Lentigo

• Solar lentigines are benign, brownish lesions that occur on light-exposed skin surfaces from age 30 onwards, as a sign of photoaging 2.
• They are of cosmetic importance to many patients and can be found on various skin surfaces.

Treatment Options for Solar Lentigo

• Different therapeutic modalities have been tried to remove these unwanted spots, including:
  • Topical therapies, such as retinoids and fixed combinations of topical agents 3, 4.
  • Physical therapies, such as cryotherapy, lasers, and intense pulsed light 5, 4.
  • Combination-based treatments, which have shown the greatest frequency of cases with complete response 5.
• Laser-based treatments, such as Q-switched ruby laser, have been shown to be effective in removing solar lentigines with significant clinical improvement and low risk of adverse effects 2, 6.

Efficacy and Safety of Treatment Options

• Combination-based treatments and laser-based treatments were found to be the most efficacious treatment modalities, with complete response rates of 65% and 43%, respectively 5.
• Adverse events occurred most commonly with topical retinoids, followed by combination-based treatments, cryotherapy, laser-based treatments, and peels 5.
• Q-switched ruby laser was found to provide faster, superior, and long-lasting lightening compared to triple combination therapy 6.