P106 Diagnosis of acute myositis vs duschene muscular dystrophy by timing of blood’s enzyme profile

• Published in: Archives of disease in childhood Vol. 104; no. Suppl 3; p. A198
• Main Authors: Chistol, Irina, Tan, Zachary, Herrera, Alfonso R, Dillon, Michelle
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01.06.2019
• Subjects: Alanine; Alanine transaminase; Antiemetics; Aspartate aminotransferase; Blood; Childrens health; Creatine; Creatine kinase; Differential diagnosis; Duchenne's muscular dystrophy; Dystrophy; Emetics; Fever; Gait; Inflammation; Inflammatory diseases; Kinases; Liver diseases; Medical diagnosis; Movement disorders; Muscular dystrophy; Musculoskeletal diseases; Myopathy; Myositis; Pediatrics; Polymyositis; Respiratory tract; Respiratory tract diseases; Transaminase; Urine; Vaccines; Vomiting
• ISSN: 0003-9888; 1468-2044
• DOI: 10.1136/archdischild-2019-epa.461

IntroductionElevated Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) enzymes would sway a doctor toward thinking there’s a liver problem; a high CK with high ALT and AST levels suggests that something’s going on in the muscle. A correct diagnosis may prevent extensive investigations or procedures. In boys one of the worst case scenarios is Duchenne Muscular Dystrophy (DMD) a severe type of muscular dystrophy, with an incidence of 1 in 3500 male births. The initial feature in most boys with DMD is a gait disturbance, with an onset often before age 3 years. Although there is not curable, it is treatable with an importance of an early diagnosisCase presentationA 26 months old boy presented to our Paediatric Assessment Unit with a history of fever up to 38°C, vomiting, and poor oral intake. His urine was red in colour, but dipstick and microscopy negative for blood. He had no significant past medical history. Vaccinations were up to date. No history of foreign travel. His development was normal.On examination he had signs of an upper respiratory tract infection. His inflammatory markers were elevated and he was commenced on IV Augmentin. He received IV fluids antipyretics and anti-emetics.The following day he refused to weight bear. On repeat blood tests, his ALT value was elevated and remained high on repeat testing. Ancillary test for assessment of liver disease were requested. A Creatine Kinase (CK) was requested and showed a value of 20248 IU/L.He started to weight bear after 4 days and this continued to improve. CK values decreased quickly in the following two weeks. His neurological exam was normal at clinic follow up 2 months post discharge and his LFTs have now returned to normal.DiscussionsIn the absence of liver pathology, raised transaminase may be an early sign of occult myopathy and such patients should have CK levels checked to look for evidence of muscular involvement as happens in polymyositis and muscular dystrophy as in Duchenne’s (DMD).In DMD, CK levels typically rise above 10,000 IU/L, but they do not return to normal in a few weeks time. It helps to make a clinical differential diagnosis without performing complex genetic tests for Duchenne’s. Laboratory investigations together with the coryzal symptoms from the onset were consistent with our diagnosis of acute viral myositis.