Klippel-Trenaunay syndrome: symptoms, diagnosis and management

A syndrome is a collection of features that tend to appear together. Great Ormond Street Hospital (GOSH) describes Klippel-Trenaunay syndrome as a combination of port wine stains, varicose veins and hypertrophy, meaning extra growth, of one limb. It is named after the two French doctors who described it in 1900.

The condition is present at birth. In many babies the only visible sign is the port wine stain, a flat red or purple mark on the skin, so the full picture may only emerge as the child grows. GOSH says that the cause is not really known; theories include problems with how the blood vessel system develops during pregnancy, but more research is needed.

GOSH explains that the port wine stain varies in shape depending on the body part. On the leg it is usually patchy, while on the chest and abdomen it tends to affect one side of the body with a definite edge. In most cases it is on the same side as the limb with varicose veins and overgrowth. Some children have smaller stains elsewhere, such as the other limb, head or neck.

The varicose veins are described as much larger than normal varicose veins and covering a wider area, generally the whole leg from foot to thigh and sometimes the buttocks and abdomen. They may become more visible as the child grows. If an arm is affected, the veins may look prominent. GOSH adds that there is a small risk of blood clots developing.

Limb hypertrophy may not be noticeable at birth or in early childhood. The affected limb, usually a leg, is longer and wider because the skin and muscles grow more and become thicker. GOSH gives an average length difference of about two centimetres, though it can be more or less. Growth happens in irregular phases, so it is hard to predict. The difference can cause an uneven walking style, and may make the spine look curved, which GOSH says results from the hip being out of line rather than a primary spine problem.

GOSH says the syndrome may be suspected in a child with a port wine stain covering an arm or leg, but that the diagnosis may not be confirmed until the child is walking and the varicose veins and limb overgrowth become more obvious. Generally a child needs to have all three features to be diagnosed.

Before any treatment of the veins, GOSH notes that a detailed scan of the leg veins is used, because there is a chance that deeper blood vessels could be involved, which could affect the blood supply to the rest of the leg. Care is typically coordinated by a multidisciplinary team, with dermatology, orthopaedic, vascular and general surgery input.

Because the syndrome itself cannot be treated, management is aimed at each feature. GOSH describes the approach as follows.

• Port wine stain: some respond to laser treatment, usually to a limited degree. A leg stain may be less noticeable than one on the face.

• Varicose veins: usual vein removal or tying off is not advised in children with this condition. Resting the leg in a raised position and using compression stockings when standing or walking is usually suggested, and support stockings from an early age can reduce problems. After a detailed scan, sclerotherapy, injecting a substance to block a vein, may be suggested, though it can take many sessions months apart and is not suitable for everyone.

• Limb overgrowth: a small difference may be managed with shoe raises. If the affected leg is more than two centimetres longer, growth in that leg can be slowed with an operation called epiphysiodesis, or the shorter leg could be lengthened.

• Swelling: physiotherapy and compression can help reduce puffiness and make the leg more comfortable.

GOSH says that as a child gets older the veins may become inflamed (phlebitis), may bleed if injured and can occasionally develop ulcers if not looked after carefully. If bleeding occurs, its advice is to apply pressure to the area, place a gauze dressing over it and then the support stocking for further pressure.

Because there is a small risk of blood clots, new throbbing pain or swelling in one leg or arm, or red or darkened skin around it, should be treated as urgent. The NHS lists these as symptoms of deep vein thrombosis and advises an urgent GP appointment or NHS 111, and 999 or A&E if there is also shortness of breath or chest pain.

GOSH says Klippel-Trenaunay syndrome is lifelong and needs ongoing care, with regular reviews, often until the child is a teenager, and a transfer to adult services at 16 to 18. It should not interfere with day-to-day activities to any great degree, though sports may be less easy for some children, so a review appointment could be useful.

Care in the UK usually runs through the NHS, with referral from a GP or paediatrician to a specialist vascular anomalies or paediatric service. Some families seek an additional private opinion, particularly about laser treatment or sclerotherapy. The principles of management are the same, and a specialist team can explain which options are suitable at each age.