· Juvenile idiopathic arthritis (JIA). Considered the most common form of arthritis, JIA includes six subtypes: oligoarthritis, polyarthritis, systemic, enthesitis-related, juvenile psoriatic arthritis or undifferentiated.
· Juvenile dermatomyositis. An inflammatory disease, juvenile dermatomyositis causes muscle weakness and a skin rash on the eyelids and knuckles.
· Juvenile lupus. Lupus is an autoimmune disease. The most common form is systemic lupus erythematosus, or SLE. Lupus can affect the joints, skin, kidneys, blood and other areas of the body.
· Juvenile scleroderma. Scleroderma, which literally means “hard skin,” describes a group of conditions that causes the skin to tighten and harden.
· Kawasaki disease. This disease causes blood-vessel inflammation that can lead to heart complications.
· Mixed connective tissue disease. This disease may include features of arthritis, lupus dermatomyositis and scleroderma, and is associated with very high levels of a particular antinuclear antibody called anti-RNP.
· Fibromyalgia. This chronic pain syndrome is an arthritis-related condition, which can cause stiffness and aching, along with fatigue, disrupted sleep and other symptoms. More common in girls, fibromyalgia is seldom diagnosed before puberty.
Source https://www.arthritis.org/about-arthritis/types/juvenile-arthritis/