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What is Klippel-Trenaunay Syndrome?

Klippel-Trenaunay syndrome (KTS) is a rare disorder that affects blood vessels, soft tissues, the lymphatic [lim-FAT-ick] system, and bones. Patients who have Klippel-Trenaunay syndrome (KTS) have many abnormal blood vessels.

KTS is present at birth, or congenital. It happens equally in males and females. It usually appears in the legs but may occur in the arms or upper body.

Patients may get other skin or organ conditions alongside or caused by KTS, such as eczema [EGG-zih-muh], melanoma, alopecia [al-uh-PEE-shee-uh], or irritable bowel syndrome.

Children who are born with KTS usually have limbs of normal size that then get bigger later. This may start to happen as early as a when your child is a few months old, or it may not be noticeable until your child reaches puberty. Sometime between puberty and about age 30, your child’s port wine stain may start to develop small, bubble-like lesions that bleed.

There is no cure for KTS, and it is a progressive condition. The most effective way to manage the disease is to treat your child’s symptoms. You and your child will work with a medical team of different specialists to create a custom treatment plan.

Klippel-Trenaunay syndrome is sometimes confused with other vascular disorders such as Parkes-Weber syndrome (PWS) or CLOVES syndrome. While they share some similar symptoms, they are different conditions.


Symptoms are different for every patient, but KTS often has these characteristics:

  • Swollen or malformed veins, or other problems with blood vessels
  • A port wine stain (red birthmark) covering one or both legs or arms
  • One arm or leg that is larger than the other from abnormal bone or tissue growth, or changes in size with internal organs or the head
  • Abnormalities of the lymphatic system, with fluid buildup or swelling or development of cysts

Your child may also experience:

  • Skin sores or ulcers that may get infected
  • Bleeding from the affected limb
  • Blood in the urine
  • Rectal or vaginal bleeding
  • Pain in the limb
  • Blood clots
  • Anemia
  • Seizures

When to See a Doctor

Sometimes, doctors can see evidence of KTS in an ultrasound of an unborn baby. At birth, the baby’s port wine stain will be evident, so the doctor will likely be monitoring your child to see if they develop KTS. If your child shows symptoms of KTS or has other concerning symptoms, see your child’s doctor for a diagnosis.


Doctors are not sure exactly what causes KTS. They do know it is a rare disorder due to a mutated gene, so is present at birth. KTS is not inherited from parents.

Diagnosis and Tests

How Is Klippel-Trenaunay Syndrome Diagnosed?

Your child’s doctor will do a physical examination and ask about their medical history. They will measure your child’s arms and legs to see if they are longer than the other limb. They may want to do imaging tests to better see abnormalities in bones and tissues:

  • MRI. This test helps with evaluating your child’s tissues and any enlargement.
  • Doppler ultrasound. This test lets the doctor see look for issues with veins deep within your child’s body.
  • Angiogram. This helps with diagnosis of an abnormal connection between an artery and a vein.


Your child’s treatment for KTS will depend on their specific symptoms. Your child may be referred to an orthopedic [or-tho-PEE-dik] doctor to create a treatment plan. Nonsurgical treatment may include:

  • Antibiotics and pain medicine for swelling
  • Medicine to prevent blood clots
  • Compression garments that support blood flow back to the heart and protect the limb from trauma
  • Laser therapy to treat pain or open sores, or to lighten the color of the port wine stain
  • Sclerotherapy (SCLAIR-oh-THAIR-uh-pee) to block unneeded veins
  • Heel inserts when one leg is longer than the other

You child may need surgery to correct problems with veins. Surgical treatments include:

  • Vein resection, or removing a section of veins
  • Vein ligation, or clamping off a section of veins in a damaged section
  • Vein stripping, or using a wire to reduce swelling in a damaged vein
  • Closing the growth plate at the knee to equalize leg length
  • Removal of excess tissue growth


KTS is caused by a genetic mutation, so it can’t be prevented. It is not passed on through families.

Support and Resources

Klippel-Trenaunay syndrome [kli-PEL TRAY-now-NAY SIN-drohm] is a disorder where your child has abnormally developed blood vessels, the lymphatic system, soft tissues, and bones. The condition is present at birth. KTS affects every child in a different way, so your child’s healthcare providers will develop a unique treatment plan for them.