There are more than 100 different autoimmune and inflammatory conditions in children affecting the joints, bones, muscles, cartilage, and skin. The CDC estimates 294,000 children in the US (approximately 1 in 250) have been diagnosed with a rheumatologic condition.1
Types of Juvenile Rheumatologic Conditions
The most commonly diagnosed juvenile rheumatologic diseases are listed below:
Juvenile idiopathic arthritis (JIA). Typically, when someone says “juvenile arthritis,” they are referring to JIA. The word “juvenile” means that the disease presents before 16 years of age, and the word “idiopathic” means “of unknown cause.”
JIA is the most common form of juvenile rheumatologic disease and includes several subtypes:
- Oligoarticular JIA (only 1 to 4 joints affected in the first six months)
- Persistent Oligoarthritis (1 to 4 joints affected after six months)
- Extended Oligoarthritis (5 or more joints affected after six months)2
- Polyarticular JIA (5 or more joints; may be rheumatoid factor positive or negative)
- Systemic onset JIA (sJIA)
- Psoriatic arthritis
- Enthesitis-related JIA
- Undifferentiated JIA
Symptoms include joint pain and tenderness, swelling, warmth, and morning stiffness that lasts for six consecutive weeks or more. It typically occurs in children aged 7 to 12, but can also present in teens and infants.
Prior to the International League Against Rheumatism (ILAR) introducing the term juvenile idiopathic arthritis (JIA) in 1997, the condition was called juvenile rheumatoid arthritis (JRA).
Juvenile dermatomyositis (JDM). In JDM, the immune system attacks the blood vessels (vasculopathy), which leads to inflammation in skin (dermatitis) and muscles (myositis). It often goes undetected during the initial period of fatigue, before the typical rash appears around the eyes or on the knuckles, knees, and elbows and the child develops muscle weakness involving arms and legs.
Juvenile dermatomyositis usually first appears between the ages of 5 and 10, and girls are affected twice as often as boys. Three in 1 million children are affected annually.3
Juvenile lupus erythematosus. Lupus is an autoimmune condition where the immune system attacks the tissues and organs of the body. There are several types of lupus:4
- Pediatric systemic lupus erythematosus (pSLE or SLE). Most often, juvenile lupus refers to pediatric systemic lupus erythematosus. This type of lupus can affect almost any part of the body, including the blood, skin, kidneys, nervous system, heart, lungs, and gastrointestinal system. More than one area can be affected at a time.
- Cutaneous lupus erythematosus. This form of lupus affects only the skin and the lesions may leave scars.
- Drug-induced lupus erythematosus. This form of lupus is similar to systemic lupus; however, it is triggered by certain prescription medications, including but not limited to isoniazid, hydralazine, and procainamide.5 This type of lupus rarely affects major organs, and it may resolve once the triggering agent is removed.
- Neonatal lupus. This rare condition affects the newborns of women who have lupus, but it is not true lupus; it is caused by the passage of anti-SSA/Ro and/or anti-SSB/La antibodies from the mother to the fetus. These are antibodies typically associated with autoimmune diseases. Symptoms at birth may include skin rash, liver problems, and low blood cell counts, but these symptoms usually disappear after 6 months. Some babies develop congenital heart block, which causes a slow heartbeat that can be diagnosed before or right after birth. Depending on the degree of the heart block, the infant may need a pacemaker.
All types of lupus are unpredictable, chronic, and lifelong, though with physician support and a well-designed treatment plan, symptoms can be managed and effects can be minimized.
Juvenile scleroderma. Scleroderma (meaning “rough skin”) is an inflammatory disease best recognized by the buildup of rough, scar-like plaques on the skin. Scleroderma lesions are thick, can have many shapes and sizes, and have different pigmentation than the surrounding skin—sometimes lighter, sometimes darker. Juvenile scleroderma refers to disease that affects children. Juvenile scleroderma, like adult-onset scleroderma, is divided into two types: localized and systemic.
- Localized scleroderma, the most common type of juvenile scleroderma, can affect the skin, muscles, bones, and joints. Localized scleroderma can be further divided into linear morphea, circumscribed or plaque morphea, generalized morphea, bullous morphea, and deep morphea.6
- Systemic scleroderma (also known as systemic sclerosis) can affect the internal organs as well as the skin. It is very rare in children and most often occurs in women between ages 20 and 50.
Parents of children diagnosed with localized scleroderma are often concerned that the condition will progress into systemic scleroderma as their child ages, but it is exceptionally rare for this to happen.
Kawasaki disease (KD). Kawasaki disease (also known as Kawasaki syndrome) is an inflammatory illness affecting the blood vessels, which can lead to acquired heart disease. Early symptoms of Kawasaki disease include:
- Fever for 5 or more days
- Bloodshot eyes
- Strawberry tongue with cracked, swollen lips
- Red palms, red foot soles, and swollen hands and feet
- Swollen lymph nodes
Onset is typically before the age of 5, and it is more common in boys than girls.
Juvenile mixed connective tissue disease. Juvenile-onset mixed connective tissue disease (MCTD) is a rare autoimmune condition that has features of more than one juvenile rheumatologic condition, including arthritis, lupus, scleroderma, and dermatomyositis. Juvenile MCTD refers to disease that affects children under 16 years of age, and is three times more prevalent in girls than boys.7
Fibromyalgia. Fibromyalgia is a disease marked by chronic fatigue and widespread musculoskeletal pain. Childhood onset fibromyalgia is typically divided into two types:
- Juvenile primary fibromyalgia syndrome (JPFS). This term refers to fibromyalgia in children who have not been previously diagnosed with another inflammatory disease.
- Secondary fibromyalgia. Children who have already been diagnosed with another chronic inflammatory disease (such as arthritis or lupus) and have fibromyalgia symptoms are diagnosed with secondary fibromyalgia.
Along with pain and fatigue, children with fibromyalgia may also experience sleep disturbances and stiffness in the morning, symptoms of irritable bowel syndrome (IBS), depression, anxiety and tension, and muscle tightness.
Unfortunately, there is no single test for diagnosing juvenile rheumatologic diseases in general, or its many types specifically. Parents or guardians who suspect their child may be exhibiting symptoms of a rheumatologic disease are encouraged to consult with their child’s pediatrician. If necessary, a referral to a juvenile rheumatologist may be made.