Is pregnancy or UV therapy dangerous if you have vitiligo?

Long-term narrowband UVB therapy did not increase the risk of skin cancer.

The research team analyzed the risk of skin cancer in 60,321 vitiligo patients, dividing them by number of phototherapy sessions: 0, 1–49, 50–99, 100–199, and 200 or more.

As a result, no pattern of increasing risk with more phototherapy sessions was observed for either non-melanoma skin cancer or melanoma.

In other words, it was difficult to conclude that long-term use of narrowband UVB for vitiligo treatment increases the risk of skin cancer.

However, a tendency for increased risk of actinic keratosis was observed in patients who received 200 or more sessions.

Therefore, while there is no need to be overly afraid of long-term phototherapy itself, it is necessary to regularly check the skin condition.

In vitiligo patients who received long-term phototherapy, the risk of cardiovascular and cerebrovascular events was lower.

Comparing 3,229 vitiligo patients who received 100 or more sessions of narrowband UVB phototherapy with 9,687 patients who did not receive phototherapy, the risk of cardiovascular and cerebrovascular events was about 36% lower in the phototherapy group.

That is, both cardiovascular and cerebrovascular events were less frequent in patients who received long-term phototherapy.

Although the exact reason has not been determined, one explanation proposed is that UVB may promote vitamin D synthesis in the skin and affect nitric oxide release or immune responses.

In patients who received long-term phototherapy, the risk of major osteoporotic fractures was also lower.

In an 11-year nationwide follow-up study, vitiligo patients who received long-term narrowband UVB phototherapy had significantly lower risks of major osteoporotic fractures including the spine, hip, wrist, and humerus.

The hazard ratio was 0.699, and this difference was more pronounced in older women.

Since the UVB used in phototherapy is a wavelength that promotes vitamin D production in the skin, this may explain the results.

However, this study alone cannot conclude that UV therapy directly prevents fractures.

Other factors should also be considered, such as the possibility that patients who consistently receive phototherapy visit the hospital regularly and manage their overall health better.

Although a positive association was confirmed, this does not mean that UV therapy should be received for the purpose of preventing cardiovascular disease or fractures.

The advantage of health insurance big data research is that it can analyze results that are difficult to confirm in single-hospital studies by tracking tens of thousands of patients over a long period.

However, while health insurance claims data include diagnoses and treatment records, they do not include detailed lifestyle information such as individual patients' vitiligo severity, lesion location, diet, or exercise.

Therefore, even if the risk of cardiovascular disease or fracture is lower in patients who received phototherapy, it cannot be confirmed that the cause is the UV therapy itself.

Nevertheless, these studies provide important evidence for questions that vitiligo patients actually wonder about.

- Patients with vitiligo showed a slightly higher risk of miscarriage

- No evidence was found that long-term NB-UVB treatment increases the risk of skin cancer

- In the long-term phototherapy group, the risk of cardiovascular and cerebrovascular events was lower

- The risk of major osteoporotic fractures was also lower

In other words, there is no need to be overly afraid of pregnancy or to worry that long-term UV therapy is unconditionally harmful to the body just because you have vitiligo.

However, it is appropriate to understand that a little more careful management is needed during pregnancy, and regular skin checks are important during long-term phototherapy.