Question: What is (are) Juvenile dermatomyositis ?
Answer: Juvenile dermatomyositis has some similarities to adult dermatomyositis and polymyositis. It typically affects children ages 2 to 15 years, with symptoms that include weakness of the muscles close to the trunk of the body, inflammation, edema, muscle pain, fatigue, skin rashes, abdominal pain, fever, and contractures. Children with juvenile dermatomyositis may have difficulty swallowing and breathing, and the heart may also be affected. About 20 to 30 percent of children with juvenile dermatomyositis develop calcium deposits in the soft tissue. Affected children may not show higher than normal levels of the muscle enzyme creatine kinase in their blood but have higher than normal levels of other muscle enzymes.
Source: GARD

Question: What are the symptoms of Juvenile dermatomyositis ?
Answer: What are the signs and symptoms of Juvenile dermatomyositis? The Human Phenotype Ontology provides the following list of signs and symptoms for Juvenile dermatomyositis. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Autoimmunity 90% Chondrocalcinosis 90% Dry skin 90% Mucosal telangiectasiae 90% Muscle weakness 90% Myalgia 90% Periorbital edema 90% Skin rash 90% Telangiectasia of the skin 90% Abnormality of temperature regulation 50% Alopecia 50% Arthralgia 50% Arthritis 50% Constipation 50% Cutaneous photosensitivity 50% Flexion contracture 50% Muscular hypotonia 50% Poikiloderma 50% Pruritus 50% Restrictive lung disease 50% Skin ulcer 50% Vasculitis 50% Abdominal pain 7.5% Abnormality of the pericardium 7.5% Abnormality of the voice 7.5% Arrhythmia 7.5% Coronary artery disease 7.5% EMG abnormality 7.5% Feeding difficulties in infancy 7.5% Gastrointestinal hemorrhage 7.5% Hypertrophic cardiomyopathy 7.5% Limitation of joint mobility 7.5% Neurological speech impairment 7.5% Pulmonary fibrosis 7.5% Respiratory insufficiency 7.5% Weight loss 7.5% Autosomal dominant inheritance - Myositis - Proximal muscle weakness - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD