Vasculitis: Understanding Autoimmune Inflammation of Blood Vessels

Vasculitis isn't one disease-it's a group of rare autoimmune disorders where the body's immune system turns against its own blood vessels. Instead of protecting you, it attacks the walls of arteries, veins, and capillaries, causing inflammation, narrowing, blockages, or even ruptures. This can starve organs of oxygen and nutrients, leading to serious damage-or death-if not caught early. It doesn't discriminate by age, but who gets it and how it behaves depends heavily on which vessels are targeted and how aggressively the immune system responds.

How Vasculitis Attacks Your Blood Vessels

It can happen anywhere. A small vessel in your skin might show up as purple spots or ulcers. A medium vessel in your kidneys can cause silent kidney failure. A large vessel like the aorta or temporal artery can lead to stroke, vision loss, or heart attack. The damage isn't always obvious until it's advanced. That’s why many people go months or even years without a diagnosis-symptoms like fatigue, joint pain, or fever get written off as the flu or aging.

Types of Vasculitis: Size Matters

• Large-vessel vasculitis affects the aorta and its biggest branches. Giant cell arteritis (GCA) hits people over 50, often starting with severe headaches, jaw pain when chewing, or sudden vision loss. Takayasu arteritis mostly affects young women and can cause weak pulses in the arms or high blood pressure from narrowed arteries.
• Medium-vessel vasculitis targets arteries feeding muscles and organs. Polyarteritis nodosa can damage kidneys, nerves, and the gut, causing abdominal pain, numbness, or high blood pressure. Kawasaki disease, seen mostly in kids under 5, inflames coronary arteries-up to 25% of untreated children develop dangerous aneurysms.
• Small-vessel vasculitis is the most common and often the most dangerous. This group includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). These are often linked to ANCA antibodies, which attack white blood cells and trigger vessel inflammation. GPA can cause sinus infections, lung nodules, and kidney failure. MPA hits kidneys and lungs hard. EGPA adds asthma and high eosinophil counts to the mix.

Then there’s Buerger’s disease, tied tightly to smoking. It clogs small arteries and veins in hands and feet, leading to painful ulcers and even amputation. Quitting tobacco isn’t optional-it’s the only treatment that works.

Diagnosis: Finding the Invisible Enemy

Doctors start with basic blood tests. If your ESR (erythrocyte sedimentation rate) is over 50 mm/hr or your CRP (C-reactive protein) is above 5 mg/dL, inflammation is likely. But that’s not enough. The real clue often comes from ANCA testing. c-ANCA (targeting proteinase-3) is 80-90% specific for GPA. p-ANCA (targeting myeloperoxidase) points to MPA or EGPA. But even these aren’t perfect-some healthy people have low levels, and some patients with confirmed vasculitis test negative.

Imaging helps map the damage. Ultrasound can show thickened temporal arteries in GCA. CT or MRI scans reveal aneurysms or blockages in larger vessels. PET scans are becoming more common to spot active inflammation in arteries that aren’t easily biopsied.

But the gold standard? Tissue biopsy. A sample from an affected area-skin, kidney, lung, or temporal artery-can show the telltale signs: immune cells inside vessel walls, fibrinoid necrosis, or leukocytoclastic debris. For skin vasculitis, a biopsy often confirms the diagnosis when rashes look suspicious. For kidney involvement, a renal biopsy is critical to determine if treatment needs to be aggressive.

Treatment: Turning Off the Immune Attack

For severe cases, the goal is rapid control. That usually means high-dose prednisone (0.5-1 mg per kg daily) to crush inflammation fast. But steroids alone aren’t enough-they cause bone loss, diabetes, weight gain, and mood swings. So they’re paired with stronger drugs:

• Cyclophosphamide has been the go-to for decades. It’s powerful but can cause bladder damage and infertility.
• Rituximab targets B-cells, the immune cells that make harmful antibodies. It’s now preferred for many patients because it’s just as effective with fewer long-term risks.

Once remission is reached (often within 3-6 months), doctors switch to maintenance therapy. This lasts 18-24 months or longer to prevent relapse. Options include azathioprine, methotrexate, or continued rituximab infusions every 6 months.

Recent breakthroughs are changing the game. Avacopan, approved by the FDA in 2021, blocks a key inflammation signal (C5a). In the ADVOCATE trial, patients on avacopan plus low-dose steroids had the same remission rates as those on high-dose steroids-but with 2,000 mg less cumulative steroid exposure over a year. That means fewer side effects, faster recovery.

For giant cell arteritis, tocilizumab (an IL-6 inhibitor) is now approved as an add-on. It helps cut steroid doses in half and reduces relapse risk. For EGPA, mepolizumab (which targets eosinophils) has shown up to 50% fewer flares in trials.

Prognosis: Can You Live With It?

Survival rates vary. For polyarteritis nodosa, if no major organs are involved, 95% survive five years. If kidneys or heart are damaged, that drops to 50-75%. Kidney failure, stroke, or lung hemorrhage are the biggest killers.

Children with Kawasaki disease need cardiac follow-up for life-even if they seem fine after treatment. Coronary aneurysms can form silently and rupture years later. Adults with GCA must watch for vision loss; it can happen in hours if the ophthalmic artery gets blocked.

What You Should Watch For

• Purple or red spots, bumps, or bruises on legs that don’t fade
• Unexplained fever, fatigue, or weight loss for more than two weeks
• New headaches, jaw pain, or vision changes after age 50
• Coughing up blood or shortness of breath with no clear cause
• Abdominal pain, nausea, or bloody stools without a known GI condition
• Numbness, tingling, or weakness in hands or feet
• Severe asthma that started in adulthood, especially with sinus problems

If you have any of these and they won’t go away, don’t wait. See a rheumatologist. General practitioners often miss vasculitis because it mimics common illnesses. The average delay in diagnosis? 6 to 12 months.

Living With Vasculitis: Beyond Medication

Regular blood and urine tests are essential. Even if you feel fine, kidney damage can creep up silently. A simple urine dipstick can catch protein or blood before it’s too late.

Join a support group. Many patients feel isolated because vasculitis is so rare. Connecting with others who understand the fatigue, the fear of relapse, and the frustration of being misunderstood makes a huge difference.