Pain during topical photodynamic therapy of actinic keratoses with 5-aminolevulinic acid and red light source: randomized controlled trial

BackgroundPain is the major drawback of photodynamic therapy (PDT), an otherwise effective treatment for actinic keratoses (AKs). ObjectiveTo determine pain intensity and its dependence upon various factors during PDT with 5-aminolevulinic acid for face/scalp AKs. MethodsA prospective, randomized, within-patient comparison study was performed. Thirty-eight patients with at least two clearly definable, mild or moderate AKs were randomized to receive either a red light dose of 70 or 100J/cm(2) as a first or second split face/scalp treatment. They were blinded to the light dose administered. Pain during treatment was assessed using a visual analog scale (VAS). ResultsThe mean intensity of pain during the first treatment session was 5.00 (1.78), while during the follow-up VAS score was 4.50 (+/- 1.51). Bigger AKs (>130mm(2)) were more painful than the smaller ones (P=0.003) and AKs on the face were twice more painful than the ones on the scalp (P=0.002). Gender and patient age were poor pain predictors. Pain was independent of the patient's Fitzpatrick skin type, AK clinical grade, pretreatment fluorescence intensity, and the light dose during PDT. ConclusionPain during PDT is associated with AK location and size. Treatment of bigger lesions (>130mm(2)) results in more pain than smaller ones and treatment of the face is more painful than the scalp area.