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Inflammation is normally helpful. At times of infection, trauma or other causes of harm to the body, inflammation plays a very important role in protecting the injured tissue from further infection and starting the healing process.

It does this by increasing blood flow to the damaged tissue to both deliver important blood cells and proteins and wash away unwanted breakdown products or debris.

This process of inflammation is best seen in the skin. Inflammation can appear red and hot because of increased blood flow and the intense activity of cells. These cells leak into the skin tissues along with fluid and proteins from the blood to produce swelling.

Inflammation can also occur without trauma or infection. This is what happens in conditions such as juvenile idiopathic arthritis (JIA). The tissue that swells is the lining of the joint, and increased fluid is produced.

Together these make the joint swollen, painful and stiff to move. There is also loss of function - for example, a swollen knee or ankle makes it difficult to walk.

The overall effect of inflammation depends on how long it lasts. Short periods of inflammation, such as with an allergic reaction or reactive arthritis, generally fully resolve without long-term problems. Inflammation that lasts several months or years, or is particularly severe, may cause lasting damage to the affected area or organ.


Autoimmunity is the process behind some inflammatory diseases. The immune system is present to protect us, but in autoimmunity it becomes confused and auto reacts - this means it attacks the body, such as the joints, without specific cause.

The immune system is a complex network of cells, proteins and chemical reactions that protect us from infection by viruses and bacteria. It also helps with other processes, such as healing.

Components of the immune system include white cells (called lymphocytes and neutrophils), and proteins (such as immunoglobulins, also known as antibodies, and complements).

In autoimmunity, these cells and proteins attack a part of the body as though it were an infection. Because there is no infection it cannot be 'cleared' and the immune reaction continues to act indefinitely or until the balances and checks of the immune system come into place. These balances and checks are in constant adjustment.

In autoimmunity they are sometimes effective at controlling inflammation, at other times they are not. This is why inflammation can occur in waves causing 'flares'.

It is important to remember these natural flares and troughs in disease activity when judging the effectiveness of a treatment. It is also important to mention flares when telling others (such as school teachers) about the condition.

This is because the appearance and disappearance of inflammation can be confusing to those who are not familiar with autoimmunity or inflammatory diseases.

Conditions seen

We see a number of inflammatory and non-inflammatory conditions in our clinics. The following are some examples, but this is not an exhaustive list.

Inflammatory conditions

Juvenile idiopathic arthritis (JIA)

This is chronic arthritis in children with no other apparent cause.

  • Juvenile means it happens before the patient is 16 years old
  • Idiopathic means we don't know what causes it
  • Arthritis means joint inflammation

Systemic JIA (also called Still's disease) is a subcategory of JIA which may cause fevers and rashes with or without arthritis.

For more information please visit:

Versus Arthritis - Juvenile Idiopathic Arthritis (JIA)

Other inflammatory conditions

  • Chronic arthritis not due to JIA
  • Juvenile SLE or lupus (JSLE)
  • Juvenile dermatomyositis (JDM)
  • Scleroderma
  • Rare connective tissue disease
  • Vasculitis
  • Chronic recurrent multifocal osteomyelitis (CRMO) or chronic nonbacterial osteitis (CNO)
  • Periodic fever syndromes
  • Autoinflammatory conditions or undefined inflammatory syndromes

Non-inflammatory conditions

Non-inflammatory conditions are those where there is no obvious underlying inflammation causing the condition.

Sometimes non-inflammatory conditions can occur alongside a co-existing inflammatory condition. Sometimes it is not clear and children and young people might be transferred between clinics to facilitate the most appropriate management

We see a variety of non-inflammatory conditions in our clinics, some of which can cause musculoskeletal symptoms and pain, sometimes with a wider impact.

These include:

  • symptomatic hypermobility
  • chronic musculoskeletal pain that did not resolve with community-based care
  • isolated Raynaud's
  • chilblains, where there is concern regarding an underlying connective tissue disease.

We work alongside other specialties to treat conditions such as skeletal dysplasia.

There is a separate dedicated clinic for chronic pain, which is supported by a specialist Chronic Pain Multidisciplinary Team (MDT).

Last reviewed:16 January 2024