Treatment with 5-Aminolaevulinic Acid Methylester Is Less Painful than Treatment with 5-Aminolaevulinic Acid Nanoemulsion in Topical Photodynamic Therapy for Actinic Keratosis

Abstract

Background: Topical photodynamic therapy (PDT) is an excellent treatment option for actinic keratosis (AK). Pain is one of the major adverse effects. Objective: To compare the pain intensity during the extensive treatment of cosmetic units using 5-aminolaevulinic acid methylester (MAL) or 5-aminolaevulinic acid nanoemulsion (BF-200-ALA). Methods: 173 patients with 965 treated areas were enrolled in this retrospective monocentric study. All patients had multiple AKs and received an extensive treatment of the photodamaged area. 424 areas were treated with MAL and 541 with BF-200-ALA. Pain was rated using a standardized visual analogue scale (VAS). The number of PDT treatment interruptions was documented. Results: PDT with MAL led to a lower mean VAS score (5.0 vs. 5.8), a lower number of treatment interruptions (13.2 vs. 19.9%) and a lower amount of patients experiencing severe pain (25.0 vs. 36.0%) compared to PDT with BF-200-ALA. Conclusion: Our data shows that PDT using MAL is less painful than PDT using BF-200-ALA resulting in a significantly lower mean VAS score (p < 0.001), significantly fewer patients experiencing severe pain (p < 0.001) and a significantly (p < 0.05) lower number of treatment interruptions. Differences in selectivity for tumour cells and transport of ALA in peripheral neurons may play a role.

Dermatology Life Quality Index and Side Effects after Topical Photodynamic Therapy of Actinic Keratosis

“…These data correspond with VAS scores from our earlier studies [5,8] and publications of other authors [6,14]. Our data imply that the pain intensity corresponds with the DLQI values.…”

“…The most common adverse event during topical PDT is pain. It occurs in the majority of the patients [4,5,6,7] during illumination and declines significantly after 8 h [8]. Besides pain, PDT leads to numerous local side effects such as burning, itching, scaling, erythema, edema, pustules and hypo- or hyperpigmentation [4,7].…”

A Prospective Study of Pain Control by a 2-Step Irradiance Schedule During Topical Photodynamic Therapy of Nonmelanoma Skin Cancer

“…The pain levels of MAL-PDT have been variously described 4 as less severe 5;6;18 than or equal 7;8 to ALA-PDT. The experience from this and our earlier studies 12 indicates comparable irradiance-dependent pain thresholds that lie between 40 and 50 mW/cm 2 for ALA and MAL-PDT.…”

The interpretation of clinical studies on the photodynamic treatment of actinic keratosis

“…A number of studies have been published recently concerning modalities of photodynamic therapy (PDT) treatment for actinic keratosis in which the efficacy of several photosensitisers and/or light sources were compared [2], [3], [4], [5]. The most recent of these is the study by Dirschka and colleagues [5] which appeared recently in the British Journal of Dermatology and in which a gel formulation of 5-aminolaevulinic acid (BF-200 ALA) was found to be superior to methyl-5-aminolaevulinate (MAL).…”

“…While the extent of pain experienced during photodynamic therapy (which is deemed to be the main side-effect of PDT [6], [7]) was documented by Dirschka et al [5], possible reasons for the greater incidence of pain during the use of the narrow-band sources were not considered. In the Dirschka et al study, a comparison of the photosensitizers used showed BF-200 ALA to be superior to MAL, but again, a study with contradictory findings (Gholam et al [3]) is not discussed. While we do not wish to infer that the study performed by Dirschka and colleagues is in any way erroneous, we would nevertheless like to point out that the discussion of the results and the authors’ selection of cited literature appears to be biased towards studies supporting the authors’ own findings.…”