Incidence and profile of skin cancers in patients following ultraviolet phototherapy without psoralens: A retrospective cohort study.

BACKGROUND: Psoralen + ultraviolet-A (PUVA) is associated with photocarcinogenesis. However, carcinogenic risk with other ultraviolet phototherapies remains unclear. OBJECTIVE: Evaluate whether phototherapy without psoralens increases skin cancer risk. METHODS: Retrospective cohort study of patients treated at a teaching-hospital phototherapy center (1977-2018). Skin cancer records were validated against pathology reports. Age-standardized incidence rates (ASIRs) of skin cancer were evaluated for gender, skin phototype, diagnosis, ultraviolet modality, anatomical site; and compared to provincial population incidence rates (2003). RESULTS: In total, 3506 patients treated with broadband-ultraviolet-B, narrowband-UVB and/or combined UVAB were assessed with a mean follow-up of 7.3 years. Majority of patients had psoriasis (60.9%) or eczema (26.4%). Median number of treatments was 43 (1-3598). Overall, 170 skin cancers (17 melanoma, 33 squamous cell carcinoma and 120 basal cell carcinoma) occurred in 79 patients. Patient-based and tumor-based ASIR of skin cancer was 149 (95% CI: 112-187)/100,000 and 264 (219-309)/100,000 person-years, respectively. There was no significant difference between tumor-based ASIRs for melanoma, squamous cell carcinoma, and basal cell carcinoma compared to the general population; or in phototherapy patients with-psoriasis or eczema; or immunosuppressants. No cumulative dose-response correlation between UVB and skin cancer was seen. LIMITATIONS: Treatment and follow-up duration. CONCLUSION: No increased risk of melanoma and keratinocyte cancer was found with phototherapy.

Relationship between sun safety behaviours and modifiable lifestyle cancer risk factors and vitamin D levels.

BACKGROUND: Sun exposure is the most important environmental risk factor for causing skin cancer. PURPOSE: This study examines the relationship between sun protection behaviours and modifiable lifestyle risk factors for other cancers as well as vitamin D levels. METHODS: Cross-sectional data were analysed from two large national health surveys (n = 31, 445 and n = 5604). Sun exposure and protection were characterized by the presence of sunburn, duration of sun exposure, frequency of seeking shade, frequency of wearing a hat and frequency of wearing sunscreen. Using Statistical Analysis System (SAS) software 9.3.1, multivariate logistic regression models were compiled. RESULTS: Unhealthy behaviour practices were associated with sunburns or infrequent sun protection behaviour, such as cigarette consumption (either current or former smokers), second-hand smoke exposure, not having a regular doctor, higher level of alcohol consumption, street drug usage and low levels of fruit/vegetable consumption. Approximately one-quarter of individuals had less than the recommended value of serum vitamin D levels (<50 nmol/L), despite 39.2% of these individuals reporting ≥1 hour of sun exposure. CONCLUSION: Modifiable lifestyle risk factors for other cancers are correlated with infrequently practicing sun protection behaviours for skin cancer prevention. Therefore, cancer prevention campaigns can aim to target all these risk factors associated with different cancers. Sun exposure is not a reliable source to obtain recommended vitamin D levels and that other sources (eg. fish, egg yolk, fortified drinks and supplements) are a safer and more reliable option.

Prescribing Home Narrowband UVB Phototherapy: A Review of Current Approaches.

Conventional, full-body phototherapy equipment is costly and therefore patients are usually treated in dermatology centres. Such office-based therapy is often not feasible for those patients who live far away from a phototherapy centre due to lost time and wages, inability to travel because of extensive skin disease, or prohibitive travel costs. Home phototherapy has emerged as a modality that meets the needs of those patients. Our aim was to review available studies on UV sources, treatment protocols, efficacy, and safety of home phototherapy. A literature review was conducted on PubMed using the terms "home" AND "phototherapy" AND ("guide" OR "approach" OR "review" OR "protocol"). From the data extracted, narrowband UVB (311 nm) offers the best balance between safety and efficacy and is recommended for home phototherapy by most authors. Treatment is safe and possible adverse effects are related to overexposure (erythema, blistering). The usual treatment protocol was administering treatments on alternating days, including weekends, with dosing based on the patient's Fitzpatrick skin type. We also provide information on the available home phototherapy systems in Canada and their reimbursement. Home phototherapy is underused in Canada. Narrowband UVB phototherapy sources equipped with a 3-dimensional panel provides a practical and safe option.

Persistent polymorphous light eruption after ultraviolet A1 phototherapy.

Polymorphous light eruption (PMLE) is the most common photodermatosis and is characterized by the development of a pruritic skin eruption within a few hours to days after sun or artificial light exposure. The eruption usually takes up to two weeks to resolve in the absence of further ultraviolet radiation. PMLE has been reported as a side effect of ultraviolet A1 (UVA1) therapy but characteristics of the eruption, especially the duration until resolution after treatment, has not been described. A 37-year-old female developed an unusually persistent PMLE that lasted for 5 weeks after completion of UVA1 phototherapy.

Utilizing electromagnetic radiation for hair growth: a critical review of phototrichogenesis.

Hair loss has a high prevalence in the general population and can have significant medical and psychological sequelae. Pattern hair loss and alopecia areata represent the major reasons patients present to dermatologists in relation to hair loss. Because conventional treatment options are generally incompletely effective, novel methods for hair grown induction are being developed. The role of using electromagnetic radiation, including low-level laser therapy for the management of hair loss through phototrichogenesis, is reviewed in this article.

UVA1 phototherapy: a concise and practical review.

High intensity long-wavelength ultraviolet A (340-400 nm; UVA1) lamps were initially developed as skin research tools; over time they have proven to be useful for treating a number of chronic dermatoses. UVA1 units and dosimetry are strikingly different from conventional UV phototherapy. The therapeutic effect of UVA1 is related to the fact that its long wavelength penetrates the dermis more deeply than UVB. UVA1 radiation induces collagenase (matrix metalloproteinase-1) expression, T-cell apoptosis, and depletes Langerhans and mast cells in the dermis. UVA1 exposure stimulates endothelial cells to undergo neovascularization. Ultraviolet A1 exerts significant therapeutic effects in atopic dermatitis and morphea; there is also evidence for its use in other skin diseases, including cutaneous T-cell lymphoma and mastocytosis.