Measuring the improvement in pulsed dye laser treated port wine stains

Considerable improvement has been made over the past 20 years in the laser treatment of Port Wine Stains (PWS). The pulsed dye laser (PDL) has been developed, with a wavelength (585 nm) and pulse duration (450 µs), to produce selective photothermolysis of cutaneous blood vessels in PWS. The PDL is now considered the treatment of choice for PWS both in children and adults.1 How do we measure the effectiveness of laser treatment of PWS? There are two end points we could consider: eradication of the birthmark and patient satisfaction. Measuring eradication of the birthmark is not that simple since, despite early optimistic reports, complete eradication of a PWS occurs in only a small minority.2,3 The vast majority of patients treated with the PDL will experience lightening of their birthmark to a greater or lesser degree. Assessment of improvement by clinicians and in most published papers is subjective, comparing the affected site after treatment with a pretreatment photographic record. The paper by Currie and Monk4 attempts to assess the reliability of this assessment method. They compared intra‐assessor concordance for three different subjective scoring systems. The simplest scoring system of ‘poor, fair, good and excellent’ resulted in the highest intra‐assessor concordance.