Rheumatoid vasculitis is a serious complication of rheumatoid arthritis in which the immune system attacks the walls of blood vessels, causing inflammation that can damage skin, nerves, and internal organs. It affects an estimated 1% to 5% of people with rheumatoid arthritis, though autopsy studies suggest many milder cases go undetected during life. The condition most often develops in people who have had severe, longstanding RA.
How Rheumatoid Arthritis Damages Blood Vessels
In rheumatoid arthritis, the immune system primarily targets joints. In rheumatoid vasculitis (RV), that same misdirected immune response turns against the cells lining blood vessels. The body produces antibodies that bind to the inner surface of vessel walls, triggering a chain reaction: immune cells flood the area, the vessel wall swells, and blood flow through the vessel slows or stops entirely.
Two mechanisms drive most of the damage. First, the immune system forms clusters of antibodies called immune complexes that latch onto vessel walls and activate inflammation directly. Second, the body produces antibodies specifically targeting blood vessel cells themselves. Both pathways cause the vessel lining to become sticky and inflamed, attracting white blood cells that pile up around the vessel. This creates a prothrombotic state, meaning the blood is more likely to clot in places it shouldn’t, which can cut off oxygen to surrounding tissue.
Small arteries are involved in most patients, but medium-sized arteries can also be affected. When larger vessels are involved, the pattern can look similar to a separate condition called polyarteritis nodosa, which sometimes complicates diagnosis.
Who Is at Risk
The strongest risk factor is having severe rheumatoid arthritis for many years. RV rarely appears early in the course of RA. Smoking increases the risk, and quitting may help reduce it. Getting early, aggressive treatment for RA itself appears to lower the likelihood of developing vasculitis later, which is one reason rheumatologists push for tight disease control from the start.
Skin Signs and Nail Fold Infarcts
The skin is the most common place RV shows up visibly. The hallmark sign is nail fold infarcts: tiny, dark spots at the base or edges of the fingernails caused by small blood vessels in the nail bed becoming blocked. These look like small splinter-shaped marks or dark dots and can appear on multiple fingers at once. They may come and go as the vasculitis flares and quiets.
Beyond nail fold changes, RV can cause purpura (flat, reddish-purple spots under the skin that don’t blanch when pressed), skin ulcers that are slow to heal, and in more severe cases, areas of skin that turn black from tissue death. Leg ulcers are particularly common and can be deep and painful. Any unexplained skin changes in someone with longstanding RA should raise suspicion for vasculitis.
Nerve Damage and Mononeuritis Multiplex
One of the more disabling effects of RV is peripheral nerve damage. When inflamed blood vessels cut off blood supply to nerves, the result is a condition called mononeuritis multiplex, where individual nerves in different parts of the body fail one by one. This creates an unusual pattern: you might develop numbness or weakness in one hand, then weeks later lose sensation in a foot, with each episode affecting a distinct nerve.
The symptoms are both sensory and motor. You may feel burning or deep aching pain in the affected limb alongside patches of numbness or tingling. Muscles supplied by the damaged nerve can weaken, sometimes causing foot drop (difficulty lifting the front of your foot) or grip weakness. The pattern starts asymmetrical, hitting random nerves at random times, but as it progresses it can begin to look more like a generalized neuropathy affecting both sides. Pain is a frequent and often severe feature, combining the sharp, electric quality of nerve pain with a deeper ache in the affected limb.
Effects on Internal Organs
RV can go beyond skin and nerves to affect vital organs, though this is less common. Cardiovascular complications include inflammation of the heart muscle (myocarditis), the sac around the heart (pericarditis), and damage to the coronary arteries that can lead to heart attacks. The lungs and gastrointestinal tract can also be affected when vessels supplying those organs become inflamed and narrowed. Organ involvement is what makes RV potentially life-threatening rather than just painful.
How It Is Diagnosed
There is no single blood test that confirms RV. Diagnosis relies on combining the clinical picture (skin changes, nerve symptoms, or organ involvement in someone with known RA) with laboratory findings and, often, a tissue biopsy. A skin biopsy from an affected area typically shows inflammation concentrated around small blood vessels, with immune complex deposits visible on the vessel walls, along with debris from destroyed white blood cells.
Blood tests play a supporting role. Doctors look for signs of heightened immune activity, including very high levels of rheumatoid factor, low complement levels (proteins consumed during active immune complex formation), and markers of widespread inflammation. None of these findings alone is diagnostic, but together with the right clinical picture, they build a convincing case.
Treatment Approach
Mild RV limited to nail fold infarcts may respond to optimizing existing RA treatment. More serious cases involving nerves or organs require aggressive immune suppression, typically high-dose corticosteroids to bring the inflammation under control quickly, combined with a stronger immunosuppressive drug to maintain that control over months.
The traditional approach for severe RV uses cyclophosphamide, a powerful immunosuppressant, for the initial phase of treatment (called induction), followed by a switch to a less toxic maintenance drug. Rituximab, a biologic therapy that depletes a specific type of immune cell, has shown equal effectiveness for inducing remission with a comparable side effect profile, and is increasingly used as an alternative. In one documented case, a biologic that blocks the inflammatory molecule TNF caused nail fold infarcts to disappear within days of each injection, only for them to reappear weeks later as the drug wore off, illustrating just how directly the inflammatory process drives the vessel damage.
Treatment typically continues for months to years, with the goal of achieving and maintaining remission while gradually reducing the intensity of immunosuppression.
Prognosis and Mortality
RV carries significant risk. Mortality ranges from 12% to 14% within the first year and 26% to 60% within five years, making it one of the more dangerous complications of rheumatoid arthritis. The most common cause of death is infection, a consequence of both the disease itself suppressing parts of the immune system and the immunosuppressive drugs used to treat it.
The good news is that RV appears to be becoming less common over time as RA treatment has improved. Earlier and more effective control of rheumatoid arthritis with modern biologic therapies seems to prevent the kind of prolonged, poorly controlled disease that historically led to vasculitis. For those who do develop it, prompt recognition and treatment improve outcomes considerably.