Efficacy and safety of daylight photodynamic therapy after tailored pretreatment with ablative fractional laser or microdermabrasion: a randomized, side-by-side, single-blind trial in patients with actinic keratosis and large-area field cancerization.

BACKGROUND: Physical pretreatments can potentiate the efficacy of daylight photodynamic therapy (dPDT), but clinical comparative studies remain limited. OBJECTIVES: Performed in large skin areas with actinic keratoses (AKs) and photodamage, this blinded, randomized clinical trial compared the efficacy and safety of dPDT after tailored skin pretreatment using ablative fractional laser (AFL) or microdermabrasion (MD). METHODS: Two ≥ 50-cm2 side-by-side skin areas were randomized to receive a single treatment with AFL-dPDT or MD-dPDT. Pretreatment parameters were tailored according to AK grade and skin constitution to ensure standardized immediate end points. Subsequently, methyl aminolaevulinate was applied, followed by 2-h daylight exposure. The primary outcome comprised blinded assessment of AK clearance at the 3-month follow-up. RESULTS: In 18 patients with 832 AKs, AFL-dPDT provided significantly higher AK clearance (81% vs. 60%, P < 0·001), led to fewer new AKs (P < 0·001) and showed superior improvement in dyspigmentation (P = 0·003) and skin texture (P = 0·001) vs. MD-dPDT. Peaking at days 3-6, AFL-PDT induced more intensified local skin responses (P = 0·004), including instances of Staphylococcus aureus infection (n = 3). Patients nonetheless preferred AFL-dPDT (P = 0·077), due to lower pretreatment-related pain (P = 0·002) and superior cosmesis (P = 0·035) and efficacy compared with MD-dPDT. CONCLUSIONS: AFL-dPDT is an effective treatment for patients with AK with extensive field cancerization, although AFL pretreatment is associated with intensified local skin reactions.

Immediate-type hypersensitivity to polyethylene glycols: a review.

Polyethylene glycols (PEGs) or macrogols are polyether compounds widely used in medical and household products. Although generally considered biologically inert, cases of mild to life-threatening immediate-type PEG hypersensitivity are reported with increasing frequency. Nevertheless, awareness of PEG's allergenic potential remains low, due to a general lack of suspicion towards excipients and insufficient product labelling. Information on immediate-type reactions to PEG is limited to anecdotal reports, and the potential for PEG sensitization and cross-sensitization to PEGylated drugs and structurally related derivatives is likely underestimated. Most healthcare professionals have no knowledge of PEG and thus do not suspect PEG's as culprit agents in hypersensitivity reactions. In consequence, patients are at risk of misdiagnosis and commonly present with a history of repeated, severe reactions to a range of unrelated products in hospital and at home. Increased awareness of PEG prevalence, PEG hypersensitivity, and improved access to PEG allergy testing, should facilitate earlier diagnosis and reduce the risk of inadvertent re-exposure. This first comprehensive review provides practical information for allergists and other healthcare professionals by describing the clinical picture of 37 reported cases of PEG hypersensitivity since 1977, summarizing instances where PEG hypersensitivity should be considered and proposing an algorithm for diagnostic management.