Daylight photodynamic therapy of actinic keratosis without curettage is as effective as with curettage: a randomized clinical trial.

BACKGROUND: Guidelines for photodynamic therapy (PDT) of actinic keratosis (AK) recommend pretreatment with curettage. The impact of curettage on cure rate is, however, not well established. OBJECTIVE: The present study aimed to evaluate whether daylight PDT without curettage could be as effective as daylight PDT with curettage. METHODS: Twenty-five patients with multiple AKs were treated in two even-sized areas on the face and scalp. One area was treated with standard daylight PDT starting with curettage followed by incubation with methyl aminolevulinate (MAL) for 30 min before 2 h of daylight exposure. The other area was incubated with MAL for 1 h without prior curettage before 2 h of daylight exposure. The longer incubation time was used to obtain a sufficiently high protoporphyrin IX concentration in the non-curettaged area. RESULTS: There was no difference in cure rate 3 months after daylight PDT in areas pretreated with curettage (86%) compared to non-curettaged areas (84%) (P = 0.1). Neither was there any difference between reported pain during daylight exposure (P > 0.7) or clinically evaluated erythema the day after treatment (P = 1.0). CONCLUSION: Daylight PDT without curettage but with 1 h of MAL incubation before daylight exposure was shown to be as effective in treatment of thin AKs on the face and scalp as standard daylight PDT with curettage. This modification of daylight PDT eases the task for the clinic and makes it more convenient for the patients as well, creating the possibility of performing daylight PDT as an entirely home-based treatment for AKs of the face and scalp without training the patients to perform pretreatment.

Sun behaviour on the beach monitored by webcam photos.

OBJECTIVES: To prevent skin cancer, the general population is recommended to limit time in the sun, to wear clothes and to seek shade around noon. This study aimed to investigate the number of beachgoers, the duration of sun exposure, and clothing worn during the day on a beach in Copenhagen. STUDY DESIGN: Observational, descriptive study. METHODS: On 11 beach days in 2014 and 2015, beachgoers were counted every hour from 8:00 to 20:00. It was noted if they wore clothes or swimwear. To estimate the duration of sun exposure, it was noted how long cars were parked by the beach. RESULTS: Of the counted beachgoers 46% were present from noon to 15:00. The number of beachgoers peaked at 15:00 on weekend days (Saturdays and Sunday) and at 16:00 on working days (Monday to Friday). Both on weekend days and working days, the percentage of beachgoers wearing clothes was lowest at 13:00 when about 90% wore only swimwear. Cars were parked for 117 min on average. Around noon, the mean time expanded to 142 min. We assume this to reflect the duration of a beach visit. CONCLUSION: The results indicate a weak tendency to limit time in the sun and to seek shade when the ultraviolet radiation is strongest in the midday sun. Hopefully information about actual sun behaviour can be used to adjust campaigns.

Increased protoporphyrin IX accumulation does not improve the effect of photodynamic therapy for actinic keratosis: a randomized controlled trial.

BACKGROUND: Photodynamic therapy (PDT) with methyl aminolaevulinate (MAL) is highly effective for treating actinic keratosis (AK) on the face/scalp, but less effective on the extremities. Insufficient accumulation of protoporphyrin IX (PpIX) may cause these inferior efficacy rates. However, it is possible to increase PpIX accumulation by extending the MAL application time and/or pretreating the skin with curettage. OBJECTIVES: To investigate whether increased PpIX accumulation improves the effect of MAL-PDT for AKs in a randomized intra-individual study. METHODS: Twenty-two patients with 533 AKs on both hands were treated with MAL-PDT. To obtain different concentrations of PpIX, four symmetrical areas on each patient were randomly allocated to different regimens: (i) 3-h MAL application without prior curettage (3hC-); (ii) 3 h with curettage (3hC+); (iii) 21 h without curettage (21hC-); and (iv) 21 h with curettage (21hC+). Treatment efficacy was evaluated after 3 months, whereas PpIX fluorescence, pain and erythema were assessed during and after PDT. RESULTS: Extended MAL application with and without curettage increased PpIX accumulation significantly compared with the standard 3hC+ regimen (P = 0·001 and P = 0·002, respectively). However, the median total clearance rates did not improve accordingly: 3hC+ (55·0%), 21hC- (55·0%) and 21hC+ (53·6%). Conversely, insufficient PpIX accumulation in the 3hC- regimen led to a significantly lower clearance rate (33·3%) than the other regimens (P < 0·045). Furthermore, pain and erythema were correlated to PpIX accumulation. CONCLUSIONS: Increased PpIX accumulation does not improve the effect of MAL-PDT for AKs on the hands, but leads to worse adverse events. Different strategies are needed to improve PDT on the extremities.

Protoporphyrin IX in the skin measured noninvasively predicts photosensitivity in patients with erythropoietic protoporphyria.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare genetic disease that causes severe sensitivity to visible light as a result of protoporphyrin IX (PpIX) accumulation in the skin. OBJECTIVES: To establish a noninvasive method to measure PpIX in the skin of patients with EPP and to investigate how skin PpIX relates to erythrocyte PpIX and photosensitivity. METHODS: Skin PpIX was measured in 25 patients with EPP by calculating the difference in PpIX fluorescence before and after complete photobleaching of PpIX using controlled illumination. The patients reported symptoms during the illumination and skin erythema was measured before and after illumination. Confirmation of the presence of PpIX was obtained in seven patients by measuring the in vivo fluorescence emission spectrum. This method was used to examine skin PpIX during the hours after an illumination in seven patients. RESULTS: We established a noninvasive method to measure skin PpIX based on measurements of PpIX fluorescence before and after complete PpIX photobleaching. The patients had an average skin PpIX of 2·0 units and skin emission spectra confirmed the presence of skin PpIX (peak emission 632 nm). Skin PpIX was associated with erythrocyte PpIX (P = 0·002, R2 = 0·34), skin erythema (P = 0·001, R2 = 0·47) and symptoms during illumination. Furthermore, skin PpIX increased during the hours after illumination. CONCLUSIONS: We have developed a noninvasive method to measure skin PpIX in patients with EPP. Skin PpIX is dependent on erythrocyte PpIX and exposure of the skin to light. This method can be used for objective monitoring of treatment effect.