Pain resulting from photodynamic therapy (PDT) of skin cancer was investigated. The study included 69 lesions (60 patients) with different types of skin tumours or precursors. Protoporphyrin IX, which is produced by the topical application of delta-aminolevulinic acid, was used as a photosensitizing agent. Twenty-three of the lesions (19 patients) were examined with a fluorescence imaging system which demarcates the tumour area from the healthy skin and visualizes the contrast between the fluorescence from healthy skin and that from the tumour. EMLA is used on all patients as part of our routine PDT protocol but despite this the major side-effect of PDT is pain during treatment. There is a large variation in pain intensity experienced by the patients, as measured by a visual analogue scale (VAS). Patients with actinic keratoses experienced more pain than those with Bowen's disease or basal cell carcinoma. The mean VAS score was higher when treating lesions located on the head than when treating lesions on the torso or the extremities. Also, treatment of large skin areas resulted in more pain than treatment of small areas, and men experienced more pain than women. The pain experienced by the patients did not correlate with treatment dose, Fitzpatrick skin type, age or fluorescence intensity.

Our results imply that the photobleaching rate and primary treatment outcome are dependent on fluence rate, and that a low fluence rate (30 mW cm(-2)) seems preferable when performing PDT of AK using noncoherent light sources.

Photodynamic therapy (PDT) is an efficient treatment for actinic keratosis. A common problem, however, is pain. The aim of this study was to investigate pain during PDT for actinic keratosis. The possibility of using capsaicin cream for pain relief was also assessed. Pain was investigated during aminolaevulinic acid PDT in 91 patients. Size, redness, scaling and induration of the lesions were recorded. Maximum pain during treatment was registered, using a visual analogue scale (0-10). The pain-reducing efficacy of capsaicin was tested in a pilot study in six patients (10 lesions). These patients were pre-treated with capsaicin cream for one week before commencing PDT. Pain was found to be normally distributed around a mean value of visual analogue scale 4.6. Larger lesions gave more pain (p=0.001). The redness of the actinic lesions was found to be related to PDT-induced pain (p=0.01), the reduction of actinic area (p=0.007), and the cure rate (p=0.01). The redder the actinic area, the better the treatment outcome and the more pain experienced. Patients with the largest reduction in the actinic area experienced more pain (p=0.053). The most important factors for presence of pain seem to be the size and the redness of the lesion. No significant pain relief was experienced after pre-treatment with capsaicin.