BACKGROUND. Sclerotherapy of telangiectasias is widely used for their treat
ment, but causes skin ulceration in 0.2-1.2% of patients. The cause of this
complication is still unclear.
OBJECTIVE. We hypothesized that an arteriole is occluded because the sclero
sant gets into an arteriovenous (AV) shunt. We have looked for these commun
ications underneath the telangiectasias.
METHODS. Doppler examination was performed in 155 cases above the telangiec
tasias to reveal the presence of an AV shunt. Twenty-two positive sites wer
e excised and histologically screened for AV shunts.
RESULTS. Pulsatile sound could be detected by Doppler transducer above spid
er veins in 112 cases (72.2%). Of the 22 Doppler-positive telangiectasias,
19 AV microshunts could be found histologically.
CONCLUSIONS. Understanding the mechanism of this complication can lead to i
ts prevention. No more than 0.2 ml of sclerosant should be administered to
a single site. The warning sign of backwash of sclerosant into arterials is
the temporary blanching of the skin from the arterial spasm.