(5) Objective assessments of portwine stains

With advances in the treatment of portwine stains (PWS), it is important to develop more objective assessments than clinical observation to assist in predicting the outcome of therapy and quantification of results and in understanding the pathophysiology of PWS. Three variables have been measured in a temperature‐controlled environment: redness as a measure of haemoglobin content using a reflectance spectrophotometer, 1 blood flow using laser doppler flowmetry and skin temperature using a thermocouple, in 11 patients with facial PWS (8 male, 3 female, mean age 29·8 years), in the normal contralateral skin and in the facial skin of five healthy volunteers (3 male, 2 female, mean age 29·6 years). Results are shown in Table 1. 1PWS Contralateral skin ControlsMean ± SEM Mean ± SEM Mean ± SEMReflectance (absolute) 292·1 ± 38 146·5 ± 27 151±25 Laser flowmetry (V) 50·5 ± 18 28·6 ±15 23 ± 6 Temperature °C 34·7 ± 1·3 33·2 ± 1·8 33·2 ± 1·1Both the haemoglobin content and skin blood flow were significantly elevated in PWS compared with normal contralateral skin and controls ( P < 0·05). The PWS was warmer than the contralateral skin in 10 of 11 patients (mean difference 1·6°C, range 0·3·3°C). By cooling the PWS with ice, it was possible to reduce laser doppler flowmetry and skin temperature values to those of the contralateral normal skin, but there was no change in haemoglobin content as measured by reflectance spectrophotometry. Reflectance spectrophotometry gave a measure which correlated most closely with clinical appearances and may be used to monitor changes objectively in the laser treated PWS.