What is Vasculitis?

Vasculitis, sometimes called angiitis or arteritis, is an umbrella term for more than a dozen conditions, all of which involve inflammation of the blood vessels. These illnesses are rare in childhood, affecting roughly 20 in 100,000 youngsters under the age of 17. As a result, you may not have heard of vasculitis before your child was diagnosed, so it helps to first understand how the disease works.

The body is filled with an estimated 60,000 miles of blood vessels — elastic tubes that can range in size from about an inch wide (the aorta) to many times thinner than a human hair (capillary). These vessels deliver oxygen-rich blood and nutrients throughout the body, and remove waste products like carbon dioxide. In vasculitis, something causes the immune system — the network of organs and cells that defends the body against outside invaders, like viruses — to mistakenly attack certain blood vessels.

This autoimmune attack (“auto” means “self”) causes the blood vessel wall to become swollen and irritated, called inflammation. Inflamed blood vessels can become narrower or even close off completely. In rare cases, they may stretch and weaken so much that they develop a bulge (aneurysm), and possibly tear open (rupture). These changes in the vessels can diminish or cut off blood flow to tissues and organs, and lead to a number of serious complications.

Remember, though, that there are many different types of vasculitis. Doctors distinguish these illnesses from one another by looking at such things as what kinds of blood vessels are affected, which organs are involved and what kinds of symptoms are present.

The two most common forms of vasculitis in children are: 

  • Henoch-Schönlein purpura (HSP), which affects small blood vessels in the skin, causing a distinctive rash called purpura. It also affects small vessels in the intestines and often the kidneys. About half the children with HSP are younger than 5, although kidney problems are more likely to be severe in older children.
  • Kawasaki disease, which affects small- and medium-sized vessels throughout the body, and often the coronary arteries (blood vessels around the heart). Like HSP, Kawasaki disease tends to occur in children younger than 5.

Other forms of vasculitis are far more common in adults, but can affect some children, too. These illnesses include:

  • Churg-Strauss syndrome affects small-/medium-sized blood vessels in many parts of the body, particularly the lungs
  • Microscopic  polyangiitis usually affects small blood vessels in the kidneys, central nervous system and skin
  • Primary angiitis of the central nervous system (PACNS) affects small-/medium-sized blood vessels of the brain and spinal cord; sometimes called CNS vasculitis
  • Polyarteritis nodosa (PAN) affects small-/medium-sized blood vessels throughout body, including the skin, kidneys and peripheral nerves (nerves that travel from the spinal cord to the rest of the body)
  • Takayasu arteritis affects large blood vessels, especially the aorta (the major blood vessel that carries blood from the heart to the rest of the body)
  • Wegener granulomatosis usually affects small-/medium-sized blood vessels in the lungs, kidneys and skin

While vasculitis can’t be prevented or cured, it can go into remission, meaning the disease is not active, and its signs and symptoms go away. With early diagnosis and the right treatment, the vast majority of children with vasculitis can achieve remission and go on to lead full and normal lives.

How we care for vasculitis

Boston Children's Hospital successfully treats many kinds of childhood vasculitis. Our rheumatologists, the specialists with the most experience in diagnosing and treating vasculitis, make up one of the largest pediatric rheumatology departments in the U.S., seeing more than 4,000 outpatients and almost 1,000 inpatients every year.

Our Samara Jan Turkel Clinical Center for Pediatric Autoimmune Disease brings together pediatric rheumatologists and consulting specialists from across the hospital to offer comprehensive, coordinated care for children with vasculitis.

We’ve established unique collaborations between departments, such as the Dermatology-Rheumatology Center, which unites rheumatologists and dermatologists in caring for children with vasculitis involving the skin. Another example is the Multiple Manifestations of Autoimmune Disease Clinic, where rheumatologists and immunologists work together to help children with many autoimmune problems, including vasculitis for which a single diagnosis doesn’t fit.