Juvenile dermatomyositis (DMJ) - Positive diagnosis

For diagnosis of juvenile dermatomyositis are a series of laboratory investigations.Chronic inflammation of the muscle is evidenced by increased activity of enzymes laboratory: TGO, TGP, aldolaza, creatine phosphokinase. Their values ​​will normalize with clinical remission 2-3 weeks before installation.
Increased serum and urinary creatinine is suggestive of an increased muscle catabolism. For this purpose we resort to test dosage urinary creatinine, this is a sensitive test of muscle damage and very important in disease relapse.
20% of cases present rheumatoid factor (RF) and ANA. Appears hipergamaglobulinemia polyclonal and serum complement is normal.Supporting the diagnosis can be made by an immunological test nic.
Muscle damage is suggested route and electromyogram (EMG) to 90% of cases, but there is a close relationship between degree of muscle dysfunction and appearance of the route. Route record electromyographic potentials fibrillar, polyphasic potentials, high frequency and low amplitude.Biposia muscle has value only in proportion of 50-80% in the diagnosis.
To support the diagnosis of juvenile dermatomyositis requires the presence of five criteria:- Symmetrical muscle weakness and leg belts, the flexors of the neck prior to, with or without dysphagia or respiratory muscle involvement;- Muscle biopsy that reveals myositis, muscle necrosis, perivascular inflammatory infiltrates;- Increasing the activity of skeletal muscle enzyme levels;- Electromyogram (EMG) which includes the triad: Skin polyphasic motor unit short, muscular fibrillation, where positive sharp;- Skin changes characterized by: heliotrope rash, periorbital edema, color purple and a suggestive sign Guttron descuamativa dermatitis, skin, hands and especially on the back metacarpofalangian.Presence of at least 3-4 of the above signs pozitiveaza juvenile dermatomyositis diagnosed, the diagnosis is likely when 3 criteria are met and if possible two of the criteria associated.
The differential diagnosis of myositis is osifianta. Since clinically it is characterized by the appearance of nodule of different sizes, accompanied by local inflammatory reaction, that ultimately determine the limitation in joint movement.