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Cancer risk associated with UV nail lamps appears low, even as researchers asserted that supporting evidence is mostly of low quality.

That's according to a systematic review published in the .

Of the nine studies that were ultimately included, three were case reports, one was a cross-sectional study, and five were experimental studies. Researchers noted that available evidence is weak, while noting that patients should be cautioned even if most studies showed that prolonged and repeated exposure to UV nail lamps poses a low malignancy risk. Further, they noted that the general population's understanding of the association between UV nail lamps and skin cancer is uncertain.

The study was conducted by a team of researchers with members at McMaster University and the University of Toronto in Canada. The following study excerpts were edited for length and clarity.

How widely are UV nail lamps used? What is their safety profile for people who are exposed?

UV nail lamps have become ubiquitous in nail salons to cure gel manicures. These lamps primarily use ultraviolet A (UVA) radiation and, to a lesser extent, ultraviolet B (UVB) radiation. UV nail lamps are used because gel polish creates longer-lasting manicures compared to traditional nail polish. Individuals receiving gel manicures typically use UV lamps for 3-5 minutes per session every 2-3 weeks for indefinite periods.

With many women worldwide using nail care products, the potential cancer risk associated with UV nail lamps remains a significant concern among consumers and healthcare providers.

The possible risks linked to the use of UV nail lamps have been explored in the literature, often comparing it to tanning bed usage, which is well known as a risk factor for melanoma and non-melanoma skin cancers. However, much of the literature exploring the use of UV nail lamps is outdated.

What was the specific goal of this review?

In Canada, the incidence rates of melanoma and non-melanoma skin cancers have risen significantly over the past three decades. These rates are projected to persist and increase further in coming years.

UV nail lamps lack regulation and emit varying intensities of UV radiation. As a result, it is difficult to develop exact data related to exposure or to assess the likelihood of skin cancer associated with their usage.

Given the steady revenue growth in the beauty industry due to increased consumer consumption over the past two decades, researchers wrote, reaching a conclusion on the risk of skin malignancy from UV nail lamps is crucial for both the consumer and the healthcare system. The goal of this systematic review was to investigate the risk and provide evidence-based recommendations on UV lamp usage.

What were the key findings?

Most studies concluded that UV nail lamps did not pose a significant risk factor for the development of skin cancer.

Based on one examination of three different UV nail lamps, it was suggested a patient would need over 250 years of weekly UV nail lamp use to experience the same risk as one course of narrowband UVB phototherapy, typically consisting of 15-30 treatments over 5-10 weeks.

However, experimental studies indicated that long-term exposure may increase the risk of skin cancers. For example, UVA radiation is strongly linked to cutaneous malignancies. In one study, after 10 minutes of exposure to a UV nail lamp, an individual's hands received a dose of UVA radiation equivalent to that of an 8-hour workday. The impact of short-term UVA radiation absorption on DNA repair mechanisms and the extent of DNA damage remains uncertain.

What are the clinical take-home messages for dermatologists?

A discussion of the dangers of UVA radiation, including the potential increased risk of cutaneous malignancy with UV-cured manicures, can be included in general sun safety education. Patients can be counseled on protective measures, such as seeking salons that use LED light units for gel manicures or wearing UV-blocking gloves. In addition, patients can be advised about the characteristics of skin lesions that require prompt examination by a clinician.

Special consideration should be made for patients with a personal or family history of skin cancers, for patients taking photosensitizing medications, and for patients with lower-grade Fitzpatrick skin types. Applying broad-spectrum sunscreen before a nail appointment, or using it as a replacement for regular moisturizer during the manicure service, can also be suggested.