Little is known about skin‐related complications in Klippel–Trenaunay syndrome (KTS), a complex vascular anomaly defined by capillary malformation (CM), venous malformation (VM) ± lymphatic malformation (LM) and limb overgrowth. Reported skin‐related complications of KTS include ulceration, vascular ectasias (blebs), bleeding and infection.

To determine the spectrum, prevalence and predictors of skin‐related complications in KTS.

A retrospective review of 410 patients fulfilling KTS criteria was performed to assess for the presence of skin‐related complications.

Skin‐related complications were present in 45% of patients. Most prevalent were CM‐related complications including blebs, bleeding, thickening (25%), cellulitis (22%) and ulceration (21%). Features positively associated with skin‐related complications were presence of LM (OR 17.17; P < 0.001), VM on the buttocks/perineum/genitalia (OR 1.92; P = 0.009), CM on the feet (OR 1.77; P = 0.039) and male sex (OR 1.63; P = 0.034). Features negatively associated with skin‐related complications were CM on the trunk (OR 0.59; P = 0.029) and tissue hypertrophy of the hands (OR 0.27; P = 0.025).

Skin‐related complications affect nearly half of patients with KTS. Those with lymphatic involvement or malformation presence in the undergarment area or feet are most at risk.