To determine irradiance of ultraviolet A in ambient sunlight and optimum exposure time for PUVAsol in a North Indian location.

BACKGROUND: Psoralen with ultraviolet A is an effective photochemotherapeutic modality. A subtype of this, PUVAsol, uses sunlight as the natural source of ultraviolet A. The amount of sunlight received and the consequent ultraviolet A exposure vary according to the month in the year, time of the day and geographical location of a place. AIM: The aim of this study is to determine irradiance of ultraviolet A in ambient sunlight and optimum exposure time for PUVAsol. MATERIALS AND METHODS: This was an observational study carried out at Postgraduate Institute of Medical Education and Research, Chandigarh (30.7333°N, 76.7794°E), India using a photometer. Ultraviolet A irradiance was recorded at a fixed place at 10 AM, once weekly for a period of 12 months. RESULTS: The irradiance of peak ultraviolet A was found to be 3.1 mW/cm2 in June 2016 while irradiance of 0.64 mW/cm2 was recorded in January 2017. The exposure time needed for therapeutic dose of 2 J/cm2 was 11 min 6 s in June 2016 while exposure time for achieving therapeutic dose of 2 J/cm2 was 52 min 5 s in January 2017. The duration of exposure was found to be significantly longer in the winter months. LIMITATION: The limitation of the study is not determining ultraviolet B radiation and infrared exposure. Other limitation of this study is that the irradiance was measured only at 10 am. This data cannot be used to determine irradiance at different time points in the day as the patient may expose himself/herself to sunlight anytime depending on his/her convenience. CONCLUSIONS: The study demonstrates the mean exposure time required for a given therapeutic dose of ultraviolet A in different months. The wide variation in ultraviolet A irradiance in natural sunlight over the year in different months also suggests that exposure times for PUVAsol should be based on the season and geographical location at the site of therapy and not based on uniform guidelines.

Topical photodynamic therapy in the treatment of basal cell carcinoma in Singaporean Chinese patients.

BACKGROUND: Topical photodynamic therapy has been used for the treatment of superficial and nodular basal cell carcinomas, with varying cure rates. AIMS: This study aims to evaluate the effectiveness of topical photodynamic therapy in the treatment of superficial and nodular basal cell carcinomas in Asian patients treated at the National Skin Centre, Singapore. MATERIALS AND METHODS: A retrospective analysis of Asian patients with histologically confirmed basal cell carcinomas and treated with photodynamic therapy was performed. RESULTS: Eight Chinese patients, with an equal gender distribution and mean age of 83.4 years were included. Five of eight basal cell carcinomas were superficial while the remaining three were nodular. The basal cell carcinomas were located in the head and neck in seven patients. The overall clearance rate at 3 months was 87.5% while the clearance rate for superficial and nodular basal cell carcinomas was 100% and 66.6% respectively at 3 months. At 12 months, the overall clearance rate was 85. 7%. LIMITATIONS: This is a retrospective analysis with small patient numbers. CONCLUSIONS: In this small series of eight Asian patients, topical photodynamic therapy has been shown to be effective and generally well-tolerated in the treatment of basal cell carcinomas, particularly of the superficial subtype. However, larger studies are needed to evaluate its overall efficacy in Asian patients.

Laser and light based treatments of acne.

Medical treatments for acne vulgaris include a variety of topical and oral medications. Poor compliance, lack of durable remission, and potential side effects are common drawbacks to these treatments. Therefore, there is a growing demand for a fast, safe, and side-effect-free novel therapy. Acne often improves after exposure to sunlight, and this has led to the development of laser and other light therapies resulting in the overall ease of treatment, with minimal adverse effects. A variety of light and laser devices has been used for the treatment of acne, including the potassium titanyl phosphate laser, the 585- and 595-nm pulsed dye lasers, the 1450-nm diode laser, radiofrequency devices, intense pulsed light sources, and photodynamic therapy using 5-aminolevulinic acid and indocyanine green. These devices are thought to target the underlying pathogenic factors such as propionibacterium acnes colonization, increased sebaceous gland activity, and the cutaneous inflammatory response. In this article, we review the current status of light- and laser-based treatment of acne.

Efficacy of red light alone and methyl-aminolaevulinate-photodynamic therapy for the treatment of mild and moderate facial acne.

BACKGROUND: Photodynamic therapy (PDT) has been shown to be an effective alternative for acne. However, there is little information comparing the efficacy of red light alone and methyl aminolaevulinate (MAL)-PDT. AIMS: To compare the efficacy and tolerability of red light alone and MAL-PDT in patients with mild to moderate facial acne. METHODS: Thirty six patients with mild to moderate acne were enrolled. Eighteen patients recieved MAL-PDT and 18 received red light alone in two sessions, 2 weeks apart. Acne grade and lesion counts were assessed by blinded evaluators at baseline, 2, 4 and 10 weeks. RESULTS: At week 2, clinical improvement from acne grade II-IV to 0-I was observed in 82.3% of MAL-PDT group and 14.2% of red light alone group. Red light alone group had a gradual clinical improvement over time with a 77% response at week 10. In contrast, MAL-PDT group had a rapid clinical improvement with total response at week 10. Both treatments were significantly effective for improving acne lesions. However, MAL-PDT group had a greater response (P < 0.001). Histologically, decreased amounts of sebocytes and lipids along with atrophic sebaceous glands were observed after MAL-PDT. CONCLUSION: MAL-PDT has a quicker onset of action with a higher response than red light alone. MAL-PDT may induce a reduction in the size of the sebaceous glands and then long-term acne remission.

Efficacy of topical photodynamic therapy for keratoacanthomas: a case-series of four patients.

Topical photodynamic therapy (PDT) is an excellent treatment option for various non-melanoma skin cancers and precancerous lesions, including actinic keratosis, Bowen's disease, and basal cell carcinoma. The clinical use of PDT includes a broad range of neoplastic, inflammatory, and infectious skin diseases. There is also anecdotal evidence suggesting the efficacy of PDT for the treatment of keratoacanthomas (KA). We report a case-series of four patients with solitary KA confirmed by histology, treated with topical PDT with methylaminolevulinic acid (MAL) cream. After three sessions of PDT, the lesions completely disappeared. There was no evidence of recurrence and excellent cosmetic outcome was achieved after three years of follow-up. Topical photodynamic therapy with MAL can be a therapeutic alternative for KA with good clinical and cosmetic outcomes.

Phototherapy and photochemotherapy in childhood dermatoses.

The concept of phototherapy and photochemotherapy is not new, and sophisticated ultraviolet (UV) treatment modalities are available for almost three decades. However, phototherapy has not been used in children as extensively as in adults, probably due to long-term safety concerns. Photochemotherapy (psoralen plus UVA) is not considered to be safe in the younger age group. UV therapies can be useful treatment options for children with selected dermatological conditions provided they are used under carefully controlled conditions. Presently there is insufficient data available to provide recommendations regarding the safe maximum dose and duration of phototherapy in children. Developments of new UV delivery systems and devices are aimed at improving the safety and efficacy of phototherapy. In this review, we discuss the published literature on phototherapy and photochemotherapy in children, drawbacks of their use in pediatric population and future prospects.

Photodynamic therapy in dermatology.

Photodynamic therapy is a new modality of therapy being used for the diagnosis and treatment of many tumors. It is now being increasingly used for skin tumors and other dermatological disorders. With its range of application it is certainly the therapy of the future. Its mechanism of action is by the Type II photo-oxidative reaction. The variables are the photosensitizer, the tissue oxygenation and the light source. It has been used to treat various disorders including Bowen's disease, actinic keratoses, squamous cell carcinomas, basal cell carcinomas, and mycosis fungoides. The side-effects are fortunately mild and transient. Newer photosensitizers like methyl aminolevulinate hold a lot of promise for better therapy.