Inflammatory rheumatic diseases - an overview

Inflammatory rheumatic diseases - an overview

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Inflammatory rheumatic diseases (IRD) are one of four groups in the rheumatic spectrum.

In Germany, the number of people with inflammatory rheumatic diseases is increasing. Overall, around 2-3% of adults suffer from inflammatory rheumatic diseases. This corresponds to around 1.5 to 2.1 million people affected [1].

Inflammatory rheumatic diseases are mostly autoimmune diseases. Autoimmune disease means that the immune system recognises the body's own structures as foreign and triggers inflammatory reactions in order to fight them. In rheumatic-inflammatory autoimmune diseases, the inflammation occurs in the musculoskeletal system.

The musculoskeletal system includes bones, joints, tendons, muscles and connective tissue. Depending on the disease, however, internal organs, skin, mucous membranes or blood vessels can also be affected.

Inflammatory rheumatic diseases are often accompanied by pain and functional limitations in the musculoskeletal system. It is also accompanied by fatigue, a long-lasting form of exhaustion and exhaustion.

This article provides an overview of IRD and highlights the differences between these chronic diseases.

Rheumatoid arthritis

Rheumatoid arthritis is an autoimmune disease in which the immune system attacks the body's own cells in the inner lining of the joints. The immune system triggers inflammation in order to fight the 'foreign' cells.

This inflammation of the synovial membrane can lead to pain, swelling and stiffness. The joints of the fingers and toes are particularly affected at the beginning of the disease.

Characteristic symptoms of rheumatoid arthritis include

  • Joint stiffness in the morning, which often lasts for over an hour
  • Pain and swelling in the affected joints
  • Symmetrical joint involvement on both sides of the body
  • General tiredness and fatigue

The exact causes are not fully understood. Genetic factors, environmental influences and dysregulation of the immune system probably play a role.

Early diagnosis and treatment are important in order to prevent permanent joint damage and maintain the quality of life of those affected.

In Germany, 0.8-1.2% of the adult population live with rheumatoid arthritis. This corresponds to 560,000 to 830,000 people [1].


Spondyloarthritis (SpA) or spondyloarthritis describes a group of inflammatory rheumatic diseases that primarily affect the joints of the spine. As the axial skeleton is affected along with the spine, it is also referred to as axial spondyloarthritis (axSpA).

Spondyloarthritides overlap and can merge into one another. A distinction is made between ankylosing spondylitis (ankylosing spondylitis) and other spondyloarthritides.

Ankylosing spondylitis is an autoimmune disease in which the immune system mistakenly attacks the body's own cartilage and bone tissue in the spine. The inflammatory processes triggered by this often cause back pain. It is also known as ankylosing spondylitis or ankylosing spondylitis.

Inflammatory spinal diseases can also occur with psoriasis or be associated with chronic inflammatory bowel diseases.

If joint or back pain occurs after a bacterial inflammation of the stomach, intestines, urinary tract or genitals, this is referred to as reactive arthritis.

If symptoms of an inflammatory spinal disease occur that cannot be clearly assigned to a disease, this is referred to as undifferentiated spondyloarthropathy.

Spondyloarthritides therefore describe chronic inflammatory diseases of the spine. All spondyloarthritides can develop into ankylosing spondylitis.

According to estimates, there are 690,000-970,000 people living with spondyloarthritis in Germany, with 350,000 adults affected by ankylosing spondylitis alone [1].

Psoriatic arthritis / psoriatic arthritis

Psoriatic arthritis is also known as psoriatic arthritis. It is a chronic inflammatory joint disease (arthritis) that occurs together or with a time delay with psoriasis.

Around two million people in Germany live with psoriasis. In around one in three patients with psoriasis, chronic joint inflammation develops over the course of the disease. Skin changes in psoriasis often occur before joint symptoms become noticeable.

The first signs of psoriatic arthritis are similar to early symptoms of rheumatoid arthritis (RA). Inflammation in the small joints of the hands and feet leads to pain, swelling and stiffness. Symptoms mainly occur in the morning (morning stiffness). In contrast to rheumatoid arthritis, the symptoms of psoriatic arthritis do not occur symmetrically, but only on one side, i.e. in individual joints.

In addition to the joints, the tendon sheaths and tendon insertions on the bone can also be inflamed in psoriatic arthritis. If joints, tendons and tendon insertions are inflamed at the same time, the entire finger or toe swells. This is also referred to as sausage finger or sausage toe.

In addition to small joints, psoriatic arthritis can also affect large joints such as the knees or hips or the spine. If the spine is affected, the disease is similar to ankylosing spondylitis (spondyloarthritis).

In Germany, it is estimated that 0.11-0.32% of the adult population suffer from psoriatic arthritis. This corresponds to 170,000-220,000 people or 1.7-2.2 per 100,000 [1].


Vasculitides are a group of inflammatory rheumatic autoimmune diseases in which the immune system targets blood vessels in the body. Vasculitides are further differentiated according to the size and type of blood vessels affected (Chapel-Hill nomenclature, 2012).

Signs of vasculitis can be very non-specific. They include

  • musculoskeletal complaints (muscle and joint pain, rarely joint swelling)
  • painful reddening of the eyes and visual disturbances
  • headaches
  • Ear, nose and throat problems (bloody cold or sudden loss of hearing)
  • Numbness (for example in the feet) and paralysis
  • Gastrointestinal complaints (bloody diarrhoea, abdominal pain)
  • Skin changes (red spots, nodules, ulcers)
  • haemoptysis
  • Bloody urine

Fatigue, weight loss, fever and night sweats can also be associated with vasculitis. These symptoms can also be associated with various other diseases. It is advisable to observe symptoms closely and document them in a symptom diary, for example.

The most common vasculitis is giant cell arteritis (arteritis temporalis), which occurs in around 30 out of 100,000 people. All other vasculitides together occur in around 20 out of 100,000 people. Overall, vasculitides are rare diseases.

Polymyalgia rheumatica

Polymyalgia rheumatica is an inflammatory rheumatic autoimmune disease that leads to inflammation of the synovial membrane. It is characterised by severe pain in the neck, shoulder, back and hip muscles. Stiffening of these muscles can also occur. Polymyalgia rheumatica is also known colloquially as muscular rheumatism.

It is characterised by a symmetrical onset of pain and a diurnal pattern of pain. Pain often builds up at night and is strongest in the morning. This pain decreases during the course of the day.

According to estimates, 0.14-0.15% of the adult population (aged 40 and over) in Germany suffer from polymyalgia rheumatica, which corresponds to 66,000-71,000 patients [1].

Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune disease in which structures of the connective tissue are regarded as foreign. Sjögren's syndrome is primarily characterised by inflammation of the salivary and lacrimal glands. It is categorised as a collagenosis. Collagenoses are pathological changes in the connective tissue.

Typical symptoms include

  • Dry mouth, dry eyes, dry vaginal mucosa in women
  • Severe exhaustion or fatigue
  • Joint and muscle complaints
  • Temporarily swollen salivary glands and cervical lymph nodes
  • Dry and/or itchy skin
  • Circulatory disorders in the fingers
  • Sleep disorders

Sjögren's syndrome can occur on its own, in which case it is referred to as primary Sjögren's syndrome. Secondary Sjögren's syndrome is when another disease is present. These diseases are usually rheumatic diseases such as rheumatoid arthritis, SLE, polymyositis or even hepatitis B or hepatitis C.

According to estimates, 0.04% of the adult population in Germany suffer from Sjögren's syndrome. This corresponds to around 39 out of 100,000 people. Middle-aged women are predominantly affected by Sjögren's syndrome. The first diagnosis is often made at the age of 40-60. In proportion, one man and nine women are affected.

Systemic Lupus Erythematosus (SLE)

Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease. It is also referred to as a systemic disease, as different tissues are often affected. In SLE, the skin and vascular connective tissue of the organs are frequently affected by vasculitis and deposits of immune complexes. SLE can affect every organ system, which makes the clinical picture very diverse and the diagnosis difficult.

SLE belongs to the group of collagenoses. In Germany, around 36-50 out of every 100,000 people suffer from SLE, with women being affected more frequently than men. This corresponds to 30,000-42,000 patients [1].

More and more people in Germany suffer from inflammatory rheumatic diseases (IRD).

In IRD, the immune system mistakenly triggers reactions against the body's own structures, as it regards them as foreign. As a result, inflammation occurs in the musculoskeletal system, organs and other tissues, which can trigger pain and restrictions in freedom of movement. Fatigue is also a frequent companion of IRD.

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