Polyarteritis Nodosa

What is Polyarteritis Nodosa?

Polyarteritis nodosa, or PAN, is a severe type of vasculitis, a condition where the blood vessels become inflamed. It was first identified back in 1866. PAN typically affects the medium-sized arteries, which are major blood vessels in the body, but it can also affect smaller arteries. PAN is different from other vasculitis conditions affecting small arteries because it’s not usually associated with anti-neutrophil cytoplasmic antibodies (ANCA), a type of proteins that attack certain cells and tissues.

The interesting thing about PAN is that it can affect the entire body, but there’s also a less severe version that only affects the skin, called cutaneous polyarteritis nodosa, or CPAN. Even though CPAN is less severe, it can still cause serious health issues like painful skin ulcers, insufficient blood flow to tissues (ischemia), and painful skin lumps. Notably, although it’s rare, patients with CPAN can develop the more severe, whole-body version of PAN.

Despite primarily targeting the skin, PAN can also impact other organs in the body. An interesting fact is that the lungs are typically not affected by this condition.

What Causes Polyarteritis Nodosa?

Polyarteritis Nodosa (PAN) primary cases, or cases that aren’t caused by another disease or condition, often don’t have a clear cause. Less common are secondary PAN cases, which are linked to certain conditions like hepatitis B, hepatitis C, or a type of cancer called hairy cell leukemia.

Researchers believe that issues with the endothelial function, which is the inner layer of small blood vessels, can continue the inflammation that’s involved with PAN. Those who contract hepatitis B may develop PAN, usually within half a year after getting infected. However, the use of a vaccine against hepatitis B has reduced the number of PAN cases.

There has been a link established between PAN and a certain gene mutation in CECR1. Apart from hepatitis B, PAN has also been associated with several types of bacteria and viruses, including Klebsiella, Toxoplasma, Pseudomonas, trichinosis, parvovirus B-19, and Yersinia species. PAN has also been linked to Sjogren syndrome; rheumatoid arthritis, a type of autoimmune disease; and hairy cell leukemia, a rare type of cancer.

Risk Factors and Frequency for Polyarteritis Nodosa

Polyarteritis nodosa (PAN) is typically found in middle-aged and older adults, and is more common in men than women. A study in France found that about 30.7 in every million adults suffer from this condition.

Signs and Symptoms of Polyarteritis Nodosa

Patients with PAN, a type of disease that impacts the blood vessels, may experience a variety of symptoms if it also affects the kidneys. These symptoms often start with high blood pressure. If left untreated, PAN can lead to damage to the heart, causing symptoms like shortness of breath and swelling due to heart failure. Similar to other diseases that affect blood vessels, patients might also experience general tiredness, weight loss, fever, joint pain, and skin lesions.

High Blood Pressure
Shortness of Breath
Swelling
Tiredness
Weight Loss
Fever
Joint Pain
Skin Lesions

The skin symptoms often show up as tender, red nodules, similar to a condition called erythema nodosum. Purple spots called palpable purpura, skin discoloration known as livedo reticularis, and skin ulcers can also occur. Typically, these skin changes are more noticeable in the lower body.

Patients may also feel discomfort in the stomach and muscles. Abdominal pain, often occurring after eating, can happen early in the disease. Other symptoms in the stomach area can include feeling nauseous, vomiting, dark, tarry stools, and diarrhea. These symptoms are caused by the inflammation of arteries supplying the small intestines. In severe cases, it can lead to a lack of blood flow and rupture in the intestinal wall. If PAN affects the muscles, patients may feel muscle pain and generalized weakness.

Neurological symptoms are another aspect of PAN. In fact, nearly 70% of patients with PAN face a condition called mononeuritis multiplex, which affects the nerves leading to sensory and motor deficits. The nerves most often affected are the radial, ulnar, and peroneal nerves.

Testing for Polyarteritis Nodosa

There’s no specific lab test to diagnose Polyarteritis nodosa (PAN), a rare disease that causes inflammation of blood vessels. The diagnosis is largely based on symptoms. However, your doctor may conduct certain tests to check the health of organs like the kidneys and liver, and to rule out other diseases.

The tests might include a blood test for serum creatinine and a urinalysis to check your kidneys’ health. A liver panel and creatinine kinase test may also be performed to assess your liver’s condition. Additionally, tests for Hepatitis B and Hepatitis C will be done to exclude these diseases as the underlying cause for PAN.

Your doctor might also check levels of erythrocyte sedimentation rate and C-reactive protein, which in case of inflammation are usually high. However, these parameters are not specific to PAN and can be elevated in other conditions involving blood vessel inflammation (vasculitides).

Other tests that might be conducted to exclude similar diseases include antineutrophil cytoplasmic antibodies test, antinuclear antibodies test, complement levels test, cryoglobulins test, serum and urine protein studies, human immunodeficiency virus (HIV) serology test, and a rheumatoid factor test. These tests are useful in ruling out other conditions and vasculitides.

Even with all these tests, a biopsy, which is the removal and examination of a small piece of tissue from an affected organ, is the most definitive way to confirm PAN. In some situations, if a biopsy is not possible or practical, your doctor may recommend a mesenteric or renal arteriography. This is a special type of imaging study that uses a dye to highlight the blood vessels and can help detect any irregularities, such as aneurysms (bulges), constrictions in larger blood vessels, and possible blockage of smaller arteries.

In some cases, your doctor may opt for less invasive imaging techniques like computed tomography (CT) or magnetic resonance imaging (MRI). These tests provide detailed pictures of the inside of your body and can be useful in diagnosing conditions like PAN.

Treatment Options for Polyarteritis Nodosa

The treatment for Polyarteritis Nodosa (PAN), a serious blood vessel disease, depends on how severe the disease is. For individuals with milder forms of PAN – meaning they have general symptoms of illness, but their kidney function is normal and there is no significant damage to vital organs or loss of blood supply – they may be treated with a type of medication called glucocorticoids. This class of drugs reduces inflammation in the body.

In some cases, people with relatively mild PAN may not respond well to glucocorticoids or may have side effects. In these situations, doctors may consider using immune modulators, like azathioprine or methotrexate. These drugs help regulate the body’s immune system and reduce inflammation.

If PAN is more severe, showing signs of kidney problems, loss of blood supply, narrowing of the arteries, or bulging of the blood vessels (aneurysms), treatment usually involves a combination of glucocorticoids and other medications that suppress the body’s immune system, like cyclophosphamide.

Recently, biological agents have been increasingly used for patients with stubborn PAN cases. These medications work by targeting specific parts of the body’s immune system to reduce inflammation.

If PAN patients have associated Hepatitis B or C infections, they can also benefit from anti-viral treatment. It is important to start this treatment before adding any immune-suppressing medications for those with mild PAN. Patients with severe Hepatitis B-associated PAN may require short-term glucocorticoid treatment, plasma exchange (a procedure to remove, treat, and return the blood plasma to the body), along with antiviral therapy.

High blood pressure, a common symptom of PAN, should be treated with a medication called an angiotensin-converting enzyme (ACE) inhibitor. This medication relaxes and widens blood vessels, making it easier for blood to flow. However, it’s important to keep a close eye on kidney function during treatment; if kidney function declines significantly, a different medication should be used. Calcium channel blockers might then be used to control high blood pressure.

In cases where the disease has caused intestinal perforation (holes in the wall of the intestines), inflammation of the gallbladder, or aneurysms, surgery may be required.

When it comes to PAN (polyarteritis nodosa), a type of blood vessel inflammation, doctors may consider several similar conditions before landing on a diagnosis. These can range from certain infectious diseases to other types of blood vessel inflammation, known as vasculitides.

Infective endocarditis, an infection of the heart’s inner lining
Mycotic aneurysm with emboli, a type of aneurysm related to infection which might cause blood clots
Human immunodeficiency virus or HIV
Granulomatosis with polyangiitis, a condition causing inflammation of blood vessels
Microscopic polyangiitis, another type involving small blood vessels
Eosinophilic granulomatosis with polyangiitis, also known as Churg-Strauss syndrome, affecting multiple organs
Immunoglobulin A vasculitis, also known as Henoch-Schönlein purpura, usually seen in children
Cryoglobulinemic vasculitis, a condition causing abnormal proteins in the blood
Drug-induced vasculitis, blood vessel inflammation caused by certain medications

It is crucial for the physician to evaluate these potential diagnoses to arrive at the correct final diagnosis.

What to expect with Polyarteritis Nodosa

The recurrence of PAN, a type of blood vessel disease, is lower than related diseases but still high. Without treatment, PAN can have severe outcomes. However, with treatment, results have greatly improved. The main causes of death from PAN are kidney failure and blockages in the vessels of the abdomen, heart, or brain. Recurrences tend to happen within 5 years. Recovery is typically slow, especially if the brain is involved, which can mean a worse outcome. People with abdominal involvement also face a worse outcome due to the risk of leaks in the gut.

The best results are for patients who only have skin involvement, but there is still a risk of the disease coming back. Patients with hepatitis B who undergo seroconversion, (a process where the virus becomes inactive), have a low risk of the disease returning and usually recover.

Without treatment, between 10%-20% of patients die within 5 years, and half die within the first 3 months. With steroid treatment, the 5-year survival rate ranges from 50%-60%. Deaths typically occur due to complications of immunosuppressive therapy, stroke, rupture in the intestine, or heart attack. The outcome can be worse for patients with the following conditions:

* Protein in the urine (more than 1 gram per day)
* Kidney dysfunction
* Heart muscle disease
* Gastrointestinal involvement
* Brain involvement

Possible Complications When Diagnosed with Polyarteritis Nodosa

Complications related to PAN, or Polyarteritis Nodosa, can involve various issues like:

Gangrene of the limbs
Skin ulcers making open sores
Infarction, which is tissue death due to lack of blood supply
Formation and rupture of aneurysm, a bulge in a blood vessel
Encephalopathy, a brain disease that alters brain function
Stroke, a condition caused by interruption of blood supply to the brain
Heart failure, when the heart can’t pump enough blood
Renal failure, also known as kidney failure
Bowel infarction, which is death of part of the intestine due to reduced blood flow
GI bleeding, or gastrointestinal bleeding, which is bleeding in any part of the digestive tract
Peripheral neuropathy, damage to the nerves outside your brain and spinal cord

Recovery from Polyarteritis Nodosa

People with PAN (Polyarteritis Nodosa) need to be watched carefully for a long period of time because the disease can come back. Furthermore, it can affect new parts of the body and sometimes the amount of medication that suppresses the immune system needs to be adjusted. Due to these medications that weaken the immune system, these patients are at a higher risk of getting infections.

Preventing Polyarteritis Nodosa

If you have PAN, it’s important to understand the nature of this illness and the fact that it could potentially get worse, affecting many different parts of your body. It’s crucial to follow the schedule and dosages of your medicine to avoid these problems. Also, you should be well-informed about potential risks that may come from long-term usage of medications designed to suppress your immune system.

Frequently asked questions

Polyarteritis nodosa, or PAN, is a severe type of vasculitis where the blood vessels become inflamed. It primarily affects the medium-sized arteries in the body but can also affect smaller arteries. Unlike other vasculitis conditions, PAN is not usually associated with anti-neutrophil cytoplasmic antibodies (ANCA).

About 30.7 in every million adults suffer from Polyarteritis Nodosa.

The signs and symptoms of Polyarteritis Nodosa (PAN) include: - High blood pressure - Shortness of breath - Swelling - Tiredness - Weight loss - Fever - Joint pain - Skin lesions, such as tender, red nodules, palpable purpura (purple spots), livedo reticularis (skin discoloration), and skin ulcers (typically more noticeable in the lower body) - Stomach discomfort, including abdominal pain (especially after eating), nausea, vomiting, dark, tarry stools, and diarrhea (caused by inflammation of arteries supplying the small intestines) - Muscle pain and generalized weakness (if PAN affects the muscles) - Neurological symptoms, with nearly 70% of patients experiencing mononeuritis multiplex, which affects the nerves leading to sensory and motor deficits (most often affecting the radial, ulnar, and peroneal nerves).

Polyarteritis Nodosa (PAN) can be primary, meaning it doesn't have a clear cause, or secondary, which is linked to certain conditions like hepatitis B, hepatitis C, or hairy cell leukemia. It can also be associated with certain gene mutations and various bacteria and viruses.

The doctor needs to rule out the following conditions when diagnosing Polyarteritis Nodosa: 1. Infective endocarditis, an infection of the heart's inner lining. 2. Mycotic aneurysm with emboli, a type of aneurysm related to infection which might cause blood clots. 3. Human immunodeficiency virus or HIV. 4. Granulomatosis with polyangiitis, a condition causing inflammation of blood vessels. 5. Microscopic polyangiitis, another type involving small blood vessels. 6. Eosinophilic granulomatosis with polyangiitis, also known as Churg-Strauss syndrome, affecting multiple organs. 7. Immunoglobulin A vasculitis, also known as Henoch-Schönlein purpura, usually seen in children. 8. Cryoglobulinemic vasculitis, a condition causing abnormal proteins in the blood. 9. Drug-induced vasculitis, blood vessel inflammation caused by certain medications.

The types of tests that are needed for Polyarteritis Nodosa (PAN) include: - Blood test for serum creatinine - Urinalysis - Liver panel - Creatinine kinase test - Tests for Hepatitis B and Hepatitis C - Levels of erythrocyte sedimentation rate and C-reactive protein - Antineutrophil cytoplasmic antibodies test - Antinuclear antibodies test - Complement levels test - Cryoglobulins test - Serum and urine protein studies - Human immunodeficiency virus (HIV) serology test - Rheumatoid factor test - Biopsy (most definitive way to confirm PAN) - Mesenteric or renal arteriography (if biopsy is not possible) - Computed tomography (CT) or magnetic resonance imaging (MRI)

The treatment for Polyarteritis Nodosa (PAN) depends on the severity of the disease. For individuals with milder forms of PAN, glucocorticoids may be used to reduce inflammation in the body. If glucocorticoids are not effective or have side effects, immune modulators like azathioprine or methotrexate may be considered. In more severe cases of PAN, a combination of glucocorticoids and other medications that suppress the immune system, such as cyclophosphamide, may be used. Biological agents that target specific parts of the immune system to reduce inflammation are also increasingly used. Anti-viral treatment may be beneficial for PAN patients with associated Hepatitis B or C infections. High blood pressure, a common symptom of PAN, can be treated with an angiotensin-converting enzyme (ACE) inhibitor. Surgery may be required for complications such as intestinal perforation, gallbladder inflammation, or aneurysms caused by PAN.

When treating Polyarteritis Nodosa (PAN), the side effects of the medications used can vary depending on the specific drug. However, some potential side effects to be aware of include: - Glucocorticoids (such as prednisone): These drugs can cause side effects such as weight gain, increased appetite, mood changes, difficulty sleeping, high blood pressure, increased risk of infection, and thinning of the bones (osteoporosis). - Immune modulators (such as azathioprine or methotrexate): These drugs can have side effects such as nausea, vomiting, liver toxicity, increased risk of infection, and bone marrow suppression. - Cyclophosphamide: This medication can cause side effects such as nausea, vomiting, hair loss, increased risk of infection, bladder problems, and an increased risk of certain types of cancer. - Biological agents: These medications can have side effects such as increased risk of infection, allergic reactions, and infusion reactions. - ACE inhibitors: These medications can cause side effects such as low blood pressure, dizziness, cough, and kidney problems. It's important to discuss potential side effects with your doctor and weigh the risks and benefits of each medication. Regular monitoring and follow-up with your healthcare team can help manage and minimize any potential side effects.

The prognosis for Polyarteritis Nodosa (PAN) can vary depending on the severity of the disease and the organs involved. Without treatment, the mortality rate is high, with 10%-20% of patients dying within 5 years and half dying within the first 3 months. However, with steroid treatment, the 5-year survival rate ranges from 50%-60%. The outcome can be worse for patients with certain conditions such as protein in the urine, kidney dysfunction, heart muscle disease, gastrointestinal involvement, and brain involvement.

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