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

Background: Pain is the major drawback of photodynamic therapy (PDT), an otherwise effective treatment for actinic keratoses (AKs).

Objective: To determine pain intensity and its dependence upon various factors during PDT with 5-aminolevulinic acid for face/scalp AKs.

Methods: A 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 100 J/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).

Results: The 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 (> 130 mm(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.

Conclusion: Pain during PDT is associated with AK location and size. Treatment of bigger lesions (> 130 mm(2) ) results in more pain than smaller ones and treatment of the face is more painful than the scalp area.