Ultraviolet phototherapy for cutaneous diseases: a concise review

Perceptions of U.S. dermatology residency program directors regarding the adequacy of phototherapy training during residency

BACKGROUND/PURPOSE

Phototherapy utilization has declined over the last 20 years despite its efficacy and cost-effectiveness. Adequacy of phototherapy training in residency may be a contributing factor. The purpose of this study was to evaluate perceptions of U.S. dermatology residency program directors (PDs) regarding the effectiveness of their programs' phototherapy training and what constitutes adequate phototherapy education.

METHODS

A questionnaire was sent to PDs to assess phototherapy training within their program; aspects such as dedicated time, exposure to different modalities, and barriers to resident education were surveyed. We assessed the statistical association between these aspects and the perception by PDs that a program's training was adequate. Statistical testing was reported using Fisher's exact tests.

RESULTS

A total of 42 PDs responded. Residency training in oral psoralen and ultraviolet A therapy (PUVA), home phototherapy, and excimer laser, respectively, is not provided in 19.0%, 31.0%, and 47.6% of programs. 38.1% of programs provide ≤5 hours of phototherapy training over 3 years of training. 59.5% of PDs cited lack of curriculum time as the most common barrier to phototherapy education. 19.0% of PDs reported completely adequate phototherapy training, which was significantly associated with inclusion of faculty-led didactics, assigned reading, or hands-on clinical training in the curriculum.

CONCLUSIONS

There is a mismatch between the resources devoted to phototherapy education and the need for dedicated training reported by PDs. Limited time is allocated to phototherapy training during dermatology residency, and a large majority of PDs do not feel that the phototherapy training offered is completely adequate.

Bactericidal effects of 310 nm ultraviolet light-emitting diode irradiation on oral bacteria

Background

Ultraviolet (UV) light is used for phototherapy in dermatology, and UVB light (around 310 nm) is effective for treatment of psoriasis and atopic dermatitis. In addition, it is known that UVC light (around 265 nm) has a bactericidal effect, but little is known about the bactericidal effect of UVB light. In this study, we examined the bactericidal effects of UVB-light emitting diode (LED) irradiation on oral bacteria to explore the possibility of using a 310 nm UVB-LED irradiation device for treatment of oral infectious diseases.

Methods

We prepared a UVB (310 nm) LED device for intraoral use to examine bactericidal effects on Streptococcus mutans, Streptococcus sauguinis, Porphyromonas gingivalis, and Fusobacterium nucleatum and also to examine the cytotoxicity to a human oral epithelial cell line (Ca9–22). We also examined the production of nitric oxide and hydrogen peroxide from Ca9–22 cells after irradiation with UVB-LED light.

Results

Irradiation with the 310 nm UVB-LED at 105 mJ/cm² showed 30–50% bactericidal activity to oral bacteria, though 17.1 mJ/cm² irradiation with the 265 nm UVC-LED completely killed the bacteria. Ca9–22 cells were strongly injured by irradiation with the 265 nm UVC-LED but were not harmed by irradiation with the 310 nm UVB-LED. Nitric oxide and hydrogen peroxide were produced by Ca9–22 cells with irradiation using the 310 nm UVB-LED. P. gingivalis was killed by applying small amounts of those reactive oxygen species (ROS) in culture, but other bacteria showed low sensitivity to the ROS.

Conclusions

Narrowband UVB-LED irradiation exhibited a weak bactericidal effect on oral bacteria but showed low toxicity to gingival epithelial cells. Its irradiation also induces the production of ROS from oral epithelial cells and may enhance bactericidal activity to specific periodontopathic bacteria. It may be useful as a new adjunctive therapy for periodontitis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-017-0382-5) contains supplementary material, which is available to authorized users.