Juvenile rheumatoid arthritis is an outdated term that refers to a group of arthritic conditions that usually start in a person’s childhood or teenage years and may continue into adulthood. Most doctors now use the term juvenile idiopathic arthritis, or JIA. Often, one of the first symptoms of JIA is a rash with or without a fever.

These arthritic conditions cause inflammation in the joints and sometimes in the internal organs.

This article describes JIA rashes and outlines some of the other symptoms associated with the condition. It also provides information on how doctors diagnose and treat JIA.

JIA is an umbrella term that comprises six subtypes of arthritis:

Children with juvenile PsA or systemic JIA subtypes may develop a rash, in which the skin becomes inflamed, irritated, and discolored.

General symptoms of juvenile PsA

Children with juvenile PsA typically experience joint symptoms, usually in the following joints:

  • the wrists
  • the fingers
  • the knees
  • the ankles

Juvenile PsA may also cause an itchy, scaly rash. This rash may develop before the joint symptoms or afterward.

General symptoms of systemic JIA

Around 10–20% of children with JIA have systemic JIA. This subtype affects the entire body, including the joints, skin, and internal organs.

Some symptoms of systemic JIA include:

  • a rash
  • a high fever of 103°F (39.4ºC) that typically spikes in the evening
  • joint pain that is typically worse in the morning or after long periods of stillness

Below are some symptoms associated with JIA subtypes that can cause a rash.

Juvenile PsA rash

Juvenile PsA rash typically presents as a flushed patch of skin that may appear silvery-white in areas due to an accumulation of dead skin cells. The rash is usually itchy or painful.

Although it may develop anywhere on the body, it most commonly affects the following areas:

  • the scalp
  • the elbows
  • the knees

This rash is persistent and does not usually present with a fever.

Systemic JIA rash

Systemic JIA rash is typically a flat, pale, non-itchy rash. It may appear on one of the following areas:

  • the abdomen
  • the arms
  • the legs

Unlike juvenile PsA rash, systemic JIA rash may last only a few minutes to a few hours. Also, it usually presents with a fever.

Healthcare professionals do not know the exact cause of JIA. However, it is likely that some children have a genetic predisposition to the condition, which something in the environment then triggers. This combination of factors then triggers an overactive immune response.

JIA subtypes that can cause rashes occur as a result of issues with a person’s innate or adaptive immunity.

With innate immunity, babies are born with an innate immune system (IIS) that is the body’s first line of defense against pathogens.

With adaptive immunity, the adaptive immune system (AIS) develops throughout a person’s life. Its purpose is to target and destroy pathogens that manage to evade the IIS.

Juvenile PsA and most other JIA subtypes are autoimmune conditions, meaning that they are due to the overactivity of the AIS. However, some researchers believe that systemic JIA is an autoinflammatory condition, meaning that it is due to the overactivity of the IIS.

Both juvenile PsA and systemic JIA cause widespread, or systemic, inflammation in multiple body tissues, including the skin.

The two JIA subtypes that can trigger a rash can have different effects on the body. The sections below outline some examples of these effects.

Juvenile PsA

Juvenile PsA rash can develop on the skin, but it may also affect the fingernails. This leads to nail psoriasis, in which the nails become pitted, discolored, and painful. In some cases, the nails may also detach from the nail bed.

Juvenile PsA can also have various effects throughout the body. Examples include:

  • pain and swelling in the joints, typically in the fingers and toes
  • swelling of the fingers, toes, or wrists
  • joint irregularities due to chronic inflammation
  • eye pain
  • fatigue

Systemic JIA

Systemic JIA can cause serious complications throughout the body. Examples include:

  • Problems with the bones and joints: Chronic inflammation slowly damages joints, resulting in pain and loss of function. It can also interfere with growth and development, causing stunted growth and limbs of different lengths.
  • Lung and heart problems: Children with systemic JIA may develop high blood pressure and lung disease. These conditions can lead to problems with circulation and breathing.
  • Macrophage activation syndrome (MAS): This is a severe inflammatory response that can overwhelm the body. Although healthcare professionals typically associate MAS with various rheumatic conditions, some experts estimate that 80% of cases are linked to systemic JIA.

There are no tests that can conclusively diagnose juvenile PsA or systemic JIA. Instead, doctors must make a diagnosis based on the following:

  • the child’s symptoms
  • the child’s medical history
  • the results of a comprehensive physical exam
  • the doctor’s clinical expertise

Certain tests can help diagnose some types of arthritis and rule out other conditions that may cause similar symptoms. Examples of these tests include blood tests and skin biopsies.

The treatment options for a JIA-related rash will depend on the underlying cause of the rash. The sections below list some potential options.

General treatments

Treatment for JIA involves addressing the underlying inflammation to reduce symptoms and prevent joint damage. Treating the inflammatory response will also help improve any rashes.

Various medications can help manage JIA symptoms, including:

  • Nonsteroidal anti-inflammatory drugs: These are typically a first line treatment that doctors prescribe to control pain in mild cases.
  • Oral corticosteroids: These drugs help reduce systemic inflammation in moderate-to-severe disease.
  • IV corticosteroids: These drugs help reduce inflammation in people with severe disease and in those with complications, such as MAS.
  • Disease-modifying antirheumatic drugs: These drugs help stop inflammatory forms of arthritis or help slow their progression.
  • Inflammatory cytokine blockers: These drugs calm the inflammatory response. Examples include anakinra and canakinumab.

Juvenile PsA treatments

Doctors may recommend topical treatments for mild juvenile PsA. Some examples include:

  • emollients to moisturize and protect the skin
  • topical steroids to reduce inflammation and slow skin cell growth
  • topical retinoids to decrease scaling and flatten thick plaques
  • vitamin D analogs, which are topical medications that help slow skin cell growth, remove scales, and reduce thick plaques

Doctors may also recommend UV light therapy and drugs called biologics to reduce the frequency of flare-ups and the severity of symptoms.

If a child develops a rash accompanied by a high fever, their parent or caregiver should seek immediate medical attention.

Rashes have multiple possible causes, and some are more serious than others. For this reason, it is best to speak with a doctor to rule out any potentially serious causes, including JIA.

JIA refers to a group of arthritic conditions that typically begin in a person’s childhood or teenage years. There are six JIA subtypes, two of which may cause a rash. These are juvenile PsA and systemic JIA.

The rashes associated with juvenile PsA and systemic JIA differ in appearance. In juvenile PsA, the rash is typically flushed, painful, or itchy, and it tends to be long lasting. In systemic JIA, the rash is typically flat, pale, and non-itchy, and it tends to disappear within minutes or hours. Systemic JIA rashes also tend to be accompanied by a high fever.

The treatment for JIA rash involves targeting the underlying inflammation and using topical medications to ease skin symptoms.

Anyone who is concerned about a rash on their child should contact a doctor for advice.