New Insights on Treating Pigmented Actinic Keratoses with Laser Technology

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Pigmented actinic keratoses (PAKs) are a notable variant of actinic keratosis, characterized by their pigmentation and association with chronic sun exposure. PAKs serve as markers of sun damage and can potentially progress to squamous cell carcinoma, making their identification and management critical in dermatology practice.¹ Traditional therapies such as cryotherapy and topical chemotherapeutics can lead to significant adverse events, prompting the exploration of laser therapy as a less invasive, effective alternative. A recent multicenter study assessed the efficacy of the Alexandrite laser in treating PAKs, with a focus on clinical relevance.²

Methods and Materials

Conducted between March 2018 and September 2023, the study involved participants aged 18 years and older from the University Hospital of Brescia and Centro Medico Polispecialistico in Pavia. Each subject presented with clinically and dermoscopically confirmed PAKs, classified according to Olsen criteria. In cases of diagnostic uncertainty, a 2 mm punch biopsy was performed to confirm the diagnosis.

Participants received treatment with the 755 nm Alexandrite laser under standardized operational parameters. Researchers stated that each session targeted the pigmented lesions, with clinical endpoints defined by the presence of erythema, edema, and changes in pigmentation immediately following therapy. Follow-up assessments occurred 3 months post-treatment.

Scoring Systems

The study employed 2 main scoring systems to evaluate treatment outcomes:

Physician's Global Assessment (PGA): This scoring system grades treatment response from complete clearance (PGA 0) to worsening of the condition (PGA 6). A score of 2 or below indicates high efficacy, while scores of 3 or above signify lower efficacy.

Target Lesion Pigmentation (TLP): The TLP scale assesses pigmentation changes compared to surrounding skin, with scores ranging from complete depigmentation (0) to significant hyperpigmentation (8).

Results

The cohort comprised 50 patients (82% women, median age 68), with a total of 60 PAKs treated. Researchers noted that most lesions were classified as Olsen Grade I. Dermoscopic analysis revealed common patterns, including pigmented pseudo-networks (51.67%) and gray-brownish dots (50%).

According to the study, the median TLP score decreased from 6 before treatment to 4 at the 3-month follow-up, indicating a “significant improvement” in pigmentation. The median PGA score post-treatment was 3, with 43.3% of lesions achieving a PGA score of 2 or lower, indicating high efficacy.

Importantly, the study reported no instances of lesion worsening or significant adverse effects related to the Alexandrite laser treatment. In cases of persistent lesions, researchers stated that traditional therapies such as cryotherapy were employed, demonstrating the laser's potential as a first-line treatment option.

Clinical Implications

The findings from this study suggested that the Alexandrite laser is a viable option for clinicians treating pigmented actinic keratoses. Researchers noted its ability to selectively target melanin minimizes damage to surrounding tissues, reducing the risk of adverse effects commonly associated with traditional treatments. They stated the significant improvement in pigmentation and the favorable safety profile underscore the need for dermatologists to consider this modality, particularly for patients concerned about cosmetic outcomes.

Conclusion

Researchers found the Alexandrite laser offers an effective and well-tolerated treatment for pigmented actinic keratoses. They wrote that the promising results from this multicenter study advocate for its integration into clinical practice, especially for patients at risk of progression to malignancy. The study also reinforces the critical importance of dermoscopic expertise in the selection and optimization of treatment for PAKs. Further research is warranted to establish long-term efficacy and optimize treatment protocols, ultimately enhancing patient care in dermatology.

References

1. Werner RN, Sammain A, Erdmann R, et al. The natural history of actinic keratosis: a systematic review. Br J Dermatol. 2013;169(3):502-518. doi:10.1111/bjd.12420
2. Bighetti S, Zane C, Zerbinati N, et al. Efficacy of alexandrite laser in the treatment of pigmented actinic keratoses: A pivotal study. LSM. 2024. doi: 10.1002/lsm.23849