What are the signs and symptoms of Dermatomyositis? The signs and symptoms of dermatomyositis may appear suddenly or develop gradually, over weeks or months. The cardinal symptom of dermatomyositis is a skin rash that precedes or accompanies progressive muscle weakness.  The rash looks patchy, with bluish-purple or red discolorations, and characteristically develops on the eyelids and on muscles used to extend or straighten joints, including knuckles, elbows, heels, and toes.  Red rashes may also occur on the face, neck, shoulders, upper chest, back, and other locations, and there may be swelling in the affected areas. The rash sometimes occurs without obvious muscle involvement.    Adults with dermatomyositis may experience weight loss or a low-grade fever, have inflamed lungs, and be sensitive to light.  Children and adults with dermatomyositis may develop calcium deposits, which appear as hard bumps under the skin or in the muscle (called calcinosis). Calcinosis most often occurs 1-3 years after the disease begins.  These deposits are seen more often in children with dermatomyositis than in adults.  In some cases of dermatomyositis, distal muscles (muscles located away from the trunk of the body, such as those in the forearms and around the ankles and wrists) may be affected as the disease progresses.  Dermatomyositis may be associated with collagen-vascular or autoimmune diseases, such as lupus.  The Human Phenotype Ontology provides the following list of signs and symptoms for 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) Abnormality of the eye 90% Autoimmunity 90% EMG abnormality 90% Muscle weakness 90% Myalgia 90% Periorbital edema 90% Abnormal hair quantity 50% Abnormality of the nail 50% Acrocyanosis 50% Arthralgia 50% Arthritis 50% Chondrocalcinosis 50% Dry skin 50% Muscular hypotonia 50% Poikiloderma 50% Pruritus 50% Pulmonary fibrosis 50% Recurrent respiratory infections 50% Respiratory insufficiency 50% Restrictive lung disease 50% Skin ulcer 50% Weight loss 50% Abnormality of eosinophils 7.5% Abnormality of temperature regulation 7.5% Abnormality of the myocardium 7.5% Abnormality of the pericardium 7.5% Abnormality of the voice 7.5% Aplasia/Hypoplasia of the skin 7.5% Arrhythmia 7.5% Cellulitis 7.5% Coronary artery disease 7.5% Cutaneous photosensitivity 7.5% Feeding difficulties in infancy 7.5% Gangrene 7.5% Gastrointestinal stroma tumor 7.5% Lymphoma 7.5% Neoplasm of the breast 7.5% Neoplasm of the lung 7.5% Neurological speech impairment 7.5% Ovarian neoplasm 7.5% Pulmonary hypertension 7.5% Telangiectasia of the skin 7.5% Vasculitis 7.5% 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.