Juvenile Dermatomyositis

Juvenile Dermatomyositis Definition

Juvenile dermatomyositis or JDM is an autoimmune disorder which causes vasculitis manifesting itself among children; and it is a pediatric equivalent of dermatomyositis. JDM manifests vasculitis an inflammation which is caused by the attack of the body's immune system to the blood vessels. In the US, the rate of occurrence of JDM is estimated to be 3 in every 1,000,000 children annually. This is about 300 to 500 fresh cases every year or about 3,000 to 5,000 children. Other types of juvenile myositis include juvenile inclusion-body myositis (JIBM) and juvenile polymyositis (JPM). These two other types are very rare and are not that as common among children. The underlying cause of Juvenile dermatomyositis is still unknown. It is most probable that it has a genetic component such as other autoimmune diseases (inherited within the family). The most common triggering factors include infections, immunizations, sunburn and injuries.

Juvenile Dermatomyositis Symptoms and Signs

The vasculitis which is caused by JDM is manifested in two ways: a distinct rash and inflammation of the muscles. The rash usually affects the patient's hands, eyelids, face, and occasionally the skin right above the joints; also the knees, knuckles and elbows. The rash is pinkish-purple in color and is named heliotrope (which is a flower with the same name and almost the same color). The rash that is found on the face and hands most often resemble allergies, fifth disease, eczema or other more common skin symptoms. The color is what sets the JDM apart from all these other symptoms, though. The rash comprises the ?dermato-? part of the illness. The next symptom (muscle inflammation) comprises the ?myositis' part of the illness. The inflammation of the muscles results into weakness of the muscles, clumsiness, fatigue, and even physical inactivity. When the condition worsens, the patient would soon suffer from the inability to do simple tasks such as lifting objects; climbing the stairs; and even doing simple manual tasks. The signs could include dysphonia, falling or dysphagia. Due to these symptoms, JDM is often misdiagnosed as muscular dystrophy or any other disease of the muscle. A few patients develop contractures (the muscle retracts and the joints remain bent). Frequent exercise can prevent contractures. The first muscles that are first to be affected tend to be the proximal muscles such as those that are located on the shoulders, neck, back and abdomen. About half of the number of patients also complains of pain.