From the Guidelines
Sun spots, also known as actinic keratoses, are keratotic lesions that occur on chronically light-exposed adult skin and carry a low risk of progression to invasive squamous cell carcinoma (SCC) 1. These lesions represent focal areas of abnormal keratinocyte proliferation and differentiation, characterized by epithelial dysplasia, which may be restricted to the basal layer or extend to full-thickness atypia 1. Some key features of sun spots include:
- Disorderly arrangement and maturation of epithelial cells
- Multiple buds of epithelial cells may occur at the membrane zone, but no invasion is seen
- Histological variants of sun spots have been described, including hypertrophic, bowenoid, lichenoid, acantholytic, and pigmented 1 It is essential to note that sun spots are a sign of skin damage caused by prolonged exposure to the sun, and their presence increases the risk of developing skin cancer 1. Therefore, it is crucial to protect the skin from further sun damage and monitor sun spots for any changes or signs of progression to SCC 1.
From the Research
Sun Spots Overview
- Sun spots, also known as 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 different therapeutic modalities have been tried to remove these unwanted spots.
Treatment Options
- The recent development of short-pulsed, pigment-specific lasers has enabled physicians to selectively destroy the pigment within the solar lentigo lesions with significant clinical improvement, low risk of adverse effects, and high patient acceptance 2.
- Combination topical therapy using 2% mequinol/0.01% tretinoin has been shown to markedly reduce lesion darkness with few side effects 3.
- Chemical peels, cryotherapy, intense pulsed light (IPL), and lasers are also effective treatment options for solar lentigines 3, 4.
- Pulsed dye laser (PDL) has been evaluated as an effective treatment option for solar lentigines, with approximately 57% of patients showing more than 75% improvement 5.
Efficacy and Safety
- Combination-based treatments and laser-based treatments have been shown to be the most efficacious treatment modalities, with the greatest frequency of cases with complete response 4.
- Adverse events, such as hypo- or hyper-pigmentation, can occur with various treatment modalities, but are generally mild and temporary 4, 5.
- It is essential to carefully evaluate pigmented lesions prior to laser treatment to distinguish benign lentigines from malignant lesions, such as melanoma 6.