Photodynamic therapy with 5-aminolaevulinic acid or placebo for recalcitrant foot and hand warts: randomised double-blind trial

Abstract

Background: Photodynamic therapy (PDT) with topical 5-aminolaevulinic acid (ALA) followed by irradiation with incoherent light (ALA-PDT) for recalcitrant warts have had beneficial results. Therefore, we undertook a randomised, parallel, double-blind clinical trial of ALA-PDT versus placeboPDT for recalcitrant foot and hand warts.

Methods: Recalcitrant foot and hand warts were randomly assigned to six repetitive ALA-PDT or placebo-PDT interventions combined with standard treatment encompassing paring followed by a keratolytic (Verucid). Standardised photographs of each wart were taken before, during (week 7) and after treatment (weeks 14 and 18). The area of each wart compared with entry area was the primary outcome variable, measured from photographs by an evaluator unaware of treatment allocation for intervention. Pain intensity immediately and 24 h after each intervention was assessed by a five-point scale.

Findings: A total of 232 foot and hand warts in 45 patients were entered into the trial: 117 warts were allocated to ALA-PDT and 115 warts to placebo-PDT. In week 14, the median relative reduction in wart area was 98% in the ALA-PDT group (interquartile range 100%, 55%) versus 52% (100%, 0) in the placebo group (p=0.0006). In week 18, the median relative reduction in wart area was 100% in the ALA-PDT group (100%, 57%) versus 71% (100%, 0) in the placebo-PDT arm (p=0.008). Both the number of vanishing warts and the difference in relative wart area of persisting warts at week 14 and 18 were significant (p<0.05) in favour of ALA-PDT. Significantly more ALA-PDT warts were graded at a higher pain intensity after treatment than placebo-PDT warts.

Interpretation: ALA-PDT is superior to placebo-PDT when both wart area and number of vanishing warts are considered.