Collagenosis: Specialists and Information

Collagenoses are autoimmune diseases. This means that the body mistakenly identifies its own tissue as foreign and, in response, produces antibodies that attack this tissue. In the case of collagenoses, the attack targets connective tissue and blood vessels. Since connective and supportive tissue is found almost everywhere in the body, in principle, all organs can be affected by the disease.

These autoimmune processes cause chronic inflammation in the body.

Generally, significantly more women than men develop these autoimmune diseases. Depending on the specific disease, the ratio can be as high as 9:1.

Collagenoses include, among others:

• systemic lupus erythematosus (SLE),
• scleroderma,
• Sjögren’s syndrome,
• polymyositis and dermatomyositis,
• Sharp syndrome.

Diseases such as systemic lupus erythematosus or scleroderma are, on the whole, relatively rare. The annual incidence rates are as follows:

• for lupus erythematosus: five to ten cases per 100,000 people,
• for scleroderma: up to ten people per 100,000 residents,
• for Sjögren’s syndrome: four cases per 100,000 people in the general population.

Lupus erythematosus, which causes distinct red
patches on the skin, is also classified as a connective tissue disease © velimir | AdobeStock

The clinical presentations of collagenopathies are very complex and diverse. Nevertheless, there are various general symptoms that frequently occur in patients with collagenoses. These include:

• Fever (often persistent and below 38.5°C),
• weight loss,
• joint pain,
• deterioration in general health.

Depending on the organ involvement, additional symptoms may appear.

For example,

• blood in the urine,
• discolored urine, and
• fluid retention in the legs

may indicate kidney involvement.

If the nervous system is affected, this can lead to

• epilepsy,
• psychosis, and
• impaired cognitive function

. Some patients also experience coagulation disorders or other bleeding disorders. The consequences are

• bleeding,
• anemia, or
• thrombosis.

Each type of collagenosis also has specific classification criteria.

For example, systemic lupus erythematosus is characterized by skin changes such as the butterfly rash or a particular sensitivity to light.

Sjögren’s syndrome is characterized by sicca symptoms such as severe dry mouth and dry eyes. A specific test can be used to assess this reduction in tear production.

Scleroderma often presents with muscle pain and stiff, waxy skin. It results in a stiff facial expression.

The course of these individual diseases varies greatly. There are very mild forms that hardly affect the lives of those affected.

However, there are also cases with severe or even life-threatening organ involvement: Patients may develop irreversible organ damage, which represents a significant disease burden.

It is not yet clear why the immune system suddenly turns against the body’s own structures.

It is believed that both genetic factors and internal and external triggers may play a role. For example, patients with systemic lupus erythematosus show increased activity of type I interferon (an immune protein).

In many collagenoses, a link can also be found between the onset of the disease and fluctuations in hormone levels. For instance, a disproportionately high number of women develop the disease after menopause or following pregnancy.

• psychological stress,
• the use of various medications, and
• viral infections

can act as triggers.

A large proportion of patients with collagenosis have organ-nonspecific antinuclear antibodies. However, it is still unclear whether these are a cause or a consequence of the disease. The antibodies damage the body’s cells, causing them to die. When the cells break down, this not only triggers an inflammatory immune response but also leads to the continued production of antinuclear antibodies.

The remaining nuclear components and the autoantibodies bind together, forming immune complexes. These complexes are deposited in organs or blood vessels, among other places. This leads to further autoimmune processes involving inflammatory reactions and damage to the affected structures.

There is no curative treatment for collagenoses. Consequently, the individual diseases cannot be cured.

However, various treatment methods are available to alleviate symptoms and prevent secondary damage. In most cases, the primary focus is on suppressing the immune system and reducing inflammatory reactions.

In milder cases, medications from the group of nonsteroidal anti-inflammatory drugs (NSAIDs) are primarily used. Well-known active ingredients in this class of drugs include ibuprofen and diclofenac. Many patients are also prescribed chloroquine, which is used worldwide primarily for the treatment and prevention of malaria.

The main indications for rheumatic diseases are skin symptoms and joint pain. If no improvement is achieved with these medications, immunosuppressive drugs such as azathioprine or cyclophosphamide are usually prescribed.

Some of these medications have a powerful effect and can also cause unwanted side effects. For this reason, the dose is increased gradually.

In particularly severe cases, the additional administration of cytostatic drugs such as methotrexate may be necessary. Depending on the severity of the disease, individual medications are combined.

The severe immunosuppression associated with the treatment of collagenoses often leads to an increased susceptibility to infections. Even minor illnesses can become life-threatening, so that treatment with antibiotics may be indicated even for trivial bacterial infections.