Microscopic Polyangiitis Explanations

In microscopic polyangiitis, the blood vessels become inflamed as a result of autoimmune processes. The cause is not yet known, but is speculatively associated with immunological programming errors after infections. The prognosis for untreated patients is unfavorable, but drug-treated patients do not necessarily have an unfavorable course.

What is microscopic polyangiitis

Microscopic polyangitis corresponds to polyarteritis nodosa, also known as Kussmaul disease. The disease falls under the vasculitis group of diseases and thus corresponds to an inflammation of the blood vessels that is caused by autoimmune processes. The condition is classified as an ANCA negative middle vessel vasculitis. See AbbreviationFinder for abbreviations related to Microscopic Polyangiitis.

The calves, forearms and internal organs are particularly affected by the inflammation of the smaller and medium-sized arteries with their inflammatory nodules arranged like a string of pearls. The inflammation is triggered by misrecognitions of the body’s own immune system. Microscopic polyangiitis is an extremely rare disease.

In a million people, the prevalence is estimated at around three new cases per year. Men are slightly more likely to get the disease than women. In many places there is even talk of a roughly twice as frequent prevalence in men. The disease usually manifests itself in middle age.


Microscopic polyangiitis is an autoimmune disease. The body’s immune system produces antibodies against body tissues, causing inflammation. So far, the causes of autoimmune diseases are not known. There is some speculation that the immune system was incorrectly programmed as part of previous infections.

The causes of primarily microscopic polyangiitis are also not definitively established. In around a third of all cases, however, the disease is associated with chronic hepatitis C genotype 2 or hepatitis B. In these cases, polyangiitis is considered secondary and merely a symptom of hepatitis, presumably caused by an overreaction of the immune system to the infection.

Infections may also play a role in the primarily ideopathic form of the disease. However, this connection is not confirmed. The only thing that is certain so far is that the immunological inflammations result in symptomatic necrosis of the vessel walls and are associated with the infiltration of neutrophilic granulocytes. The necrosis leads to vasoconstriction with thrombosis or infarction of terminal arteries.

Symptoms, Ailments & Signs

Patients with microscopic polyangiitis suffer from nonspecific symptoms such as fever, muscle pain, joint problems and night sweats or weight loss. Around 80 percent of all those affected are affected by neuropathy, which primarily affects mixed nerves above a certain size. Sometimes the central nervous system is involved.

In such a case, visual disturbances, sequelae such as strokes or epileptic seizures occur. Since there is often symptomatic high blood pressure, these symptoms are regarded as secondary consequences. In the digestive tract, the disease can manifest itself in the form of colicky abdominal pain or intestinal infarction and bleeding.

Microaneurysms of the vessels can be observed in the kidneys. In addition, cardiac symptoms such as angina pectoris or a heart attack may be present. Polyangiitis can also manifest itself on the skin, particularly in livedo racemosa or subcutaneous aneurysms. A laboratory analysis shows increased CRP and increased ESR. A leukocytosis develops.

Diagnosis & disease progression

The diagnosis of microscopic polyangiitis is made according to the ACR criteria and requires at least three out of a total of ten characteristic criteria. In addition to a weight loss of more than four kilograms, livedo reticularis, testicular pain, muscle weakness and muscle pain as well as mono- or polyneuropathies, high blood pressure and an increase in serum creatinine or urea are among the characteristic criteria.

The same applies to detectable hepatitis B or hepatitis C, angiographic abnormalities or matching arterial biopsy findings. In the differential diagnosis, microscopic polyangiitis must be differentiated from other vasculitis and systemic lupus erythematosus.

If left untreated, the prognosis is extremely poor. The five-year survival rate in untreated patients is less than 20 percent. Death usually occurs from a heart attack or stroke. For treated patients, the five-year survival rate increases to 80 percent.


As a rule, this disease causes various symptoms, which, however, in any case significantly reduce the quality of life of those affected. The patients suffer primarily from fever and also from pain in the joints or muscles. Likewise, it is not uncommon to break out in a sweat at night, which can disturb sleep.

This often results in depression or irritability in the person concerned. Furthermore, the patients also suffer from paralysis or various disorders of sensitivity that can occur anywhere in the body. Visual disturbances or hearing problems can also limit and complicate the patient’s everyday life. Abdominal pain or epileptic seizures can also occur.

These are usually associated with severe pain. In the worst case, the patients suffer a heart attack and die from it. In general, the life expectancy of those affected is significantly reduced by the disease. Pain can also often occur in the testicles.

Treatment of this disease is carried out with the help of drugs. As a rule, the course of the disease is positive. Particular complications do not limit the treatment.

When should you go to the doctor?

People who suffer from symptoms such as fever, general malaise, muscle pain or joint problems should see a doctor. Unwanted weight loss, night sweats and sleep disorders should be examined and treated. If there are visual impairments, an increased risk of accidents and an increased risk of injury, a doctor is needed. In case of abdominal pain, irregularities in the digestive tract or cramps in the upper abdomen, a doctor’s visit is necessary. Colic is a special warning of the organism. They should be checked out by a doctor as soon as possible.

In individual cases, an emergency doctor must be alerted so that emergency medical care can be guaranteed immediately. Disorders of cardiac activity and rhythm are a cause for concern. Since a heart attack is imminent in severe cases, a doctor’s visit should be made. Heart palpitations, increased blood pressure, hot flashes or inner restlessness should be examined by a doctor. Consult a doctor if you feel pressure in your chest, feel very sick or feel heavy. If an existing pain sensation spreads beyond the chest to the back or jaw, a doctor’s consultation is necessary. If there are any abnormalities in the skin’s appearance, a doctor’s visit is also advisable.

Treatment & Therapy

Polyangiitis is an incurable disease. Since the cause is not known in detail, no causal, but only symptomatic therapy can take place. The symptomatic therapy mostly corresponds to a conservative drug treatment with corticosteroids or cyclophosphamide and azathioprine. If hepatitis is present, treating that infection can interactively improve the symptoms of polyangiitis.

The success of the treatment always depends on the severity of the polyangiitis in the individual case. Patients are usually assigned a certain degree of severity using a five-factor score. The light form corresponds to a score of zero. At this level, glucocorticoids improve symptoms in half the cases. However, almost half of the patients with a remission experience a recurrence.

After such a recurrence, an immunosuppressant must be administered. Severe grade patients also receive immunosuppressants such as cyclopshosphamide and azathioprine. Glucocorticoids in a high-dose therapy lasting several weeks are a common treatment step for patients with more severe forms. ACE inhibitors are administered to reduce symptomatic high blood pressure and thus mortality from heart attacks or strokes.

Outlook & Forecast

About four out of a million people develop microscopic polyangiitis each year. This small number means, among other things, that the current state of scientific research is insufficient. But the fact is that it is an incurable disease. The therapy is aimed exclusively at the symptoms and not at the causes. Doctors give patients a score when they make a diagnosis. A lower value allows a more favorable prognosis than a higher degree of severity. In general, the quality of life and expectations have improved in recent years.

One of the problems with microscopic polyangiitis is that neoplasms form. Two years after the start of treatment, these can be found in a good third of the patients. These recurrences can only be detected at an early stage through close monitoring. In contrast, with appropriate therapeutic approaches, freedom from symptoms can be achieved in most patients for years. On average, 80 percent of all treated patients are still alive five years after diagnosis. If, on the other hand, no therapy is given, the risk of death increases significantly. Only one in five lives five years after the onset of microscopic polyangiitis.


Microscopic polyangiitis cannot be prevented to date, as the definitive causes remain unclear.


Because treatment for microscopic polyangiitis is complex and lengthy, follow-up care focuses on managing the condition with confidence. Those affected should try to build a positive attitude despite the adversity. Relaxation exercises and meditation can help calm and focus the mind.

Microscopic polyangiitis is a very rare disease that can cause significant complications. Aftercare depends heavily on the individual severity of the disease, so that the symptoms can only be alleviated, but not permanently combated. A healthy way of life with sufficient sleep and exercise in the fresh air strengthens the immune system and can increase well-being. Acute symptoms that occur repeatedly and suddenly should be clarified immediately with the doctor treating you.

You can do that yourself

Microscopic polyangiitis has not yet been cured. Treatment focuses on relieving symptoms and improving the sufferer’s quality of life. The patient can support these measures by adapting his lifestyle to the condition.

This can be achieved, for example, by changing your diet. In principle, a healthy and balanced diet with sufficient carbohydrates is recommended for microscopic polyangiitis. In addition, stimulants such as alcohol, caffeine and nicotine should be avoided. Those affected should drink enough fluids to counteract bleeding, high blood pressure and other typical symptoms of the disease. Accompanying this, drug therapy is indicated. This can be supported by the patient by keeping a complaint diary with any side effects and interactions. With the help of these notes, the doctor in charge can optimally adjust the medication to the individual symptoms and the constitution of the patient.

If visual disturbances or epileptic seizures occur, a specialist must be consulted. In addition, the patient needs support in everyday life, because the often acute symptoms increase the risk of accidents and falls. In the case of severe polyangiitis, a psychotherapist may also be consulted.