There are more than 100 different juvenile rheumatologic conditions. Some of these diseases and conditions have symptoms unique to that type of disease—for example, a strawberry-colored tongue from Kawasaki disease, or scar-like skin plaques from scleroderma—but many types also have symptoms in common. The most common symptoms are:
Pain. Children with arthritis (inflammation in joints) or myositis (inflammation in muscle) often complain of muscle and joint pain without having sustained an injury or recently participated in strenuous activity, such as upon waking and beginning to move in the morning.
Stiffness. Along with pain upon waking, children with arthritis often feel stiffness in their joints upon waking. This typically lessens throughout the day as they move.
Swelling. Inflammation is a hallmark of many types of arthritis. Swelling and warmth around affected joints that occurs without injury or activity is a warning sign of arthritis. It may persist, or may come and go with other symptoms.
Rashes. A rash that develops that is not an allergic reaction, eczema, or another common childhood rash cause is common in patients with rheumatologic diseases. It may cover the knuckles, cheeks and nose, hands and feet, or chest and stomach. It may or may not itch.
Fevers. Fever without any accompanying infection, such as the flu, may affect children with rheumatologic diseases. These fevers may be prolonged and low-grade, or they may start and end quickly, and are often accompanied by fatigue.
Other common signs of rheumatologic diseases include unexplained weight loss and eye problems.
In cases where internal organs are involved, symptoms may vary depending on which organ is affected:
- Lungs – coughing and shortness of breath
- Heart – chest pain
- Gut – abdominal pain or blood in stool
- Brain – Headaches and confusion
Causes of Juvenile Rheumatologic Diseases
Juvenile rheumatologic diseases are a collection of autoimmune disorders. In the course of these disorders, the body’s immune system attacks the body’s own cells rather than protecting the body from disease. This abnormal immune system activity is what causes pain, inflammation, and many other symptoms associated with juvenile arthritis.
The exact causes of autoimmune diseases and disorders such as juvenile idiopathic arthritis remain unknown. Research suggests that genetics plays a large role, particularly the human leukocyte antigen gene family, or HLA gene family. These genes provide the blueprints for making several proteins collectively referred to as the HLA complex. These proteins are crucial to immune system regulation, helping it recognize foreign bacteria and other invaders.1
Certain variations of genes in the HLA gene family are associated with developing autoimmune disorders, including but not limited to juvenile idiopathic arthritis, ankylosing spondylitis, and polyarthritis.2