Indeed, 17-25% of children with NAFLD develop a NASH in general, and up to 83% for children with severe obesity (versus 29% for adults), further suggesting that hepatic fibrosis seems to follow a more aggressive clinical course in children compared to adults.Early diagnosis of NAFLD in children may help prevent the development of liver disease during adulthood. This is challenging as most children with NAFLD are asymptomatic, with only 42-59% showing abdominal pain. Other symptoms might be present, such as right upper quadrant pain or acanthosis nigricans, the latter of which is often present in children with NASH. An enlarged liver occurs in 30–40% of children with NAFLD.The AASLD recommends a diagnostic liver biopsy in children when the diagnosis is unclear or before starting a potentially hepatotoxic medical therapy. The EASL suggests using fibrosis tests such as elastography, acoustic radiation force impulse imaging, and serum biomarkers to reduce the number of biopsies. In follow up, NICE guidelines recommend that healthcare providers offer children regular NAFLD screening for advanced liver fibrosis every two years using the enhanced liver fibrosis (ELF) blood test. Several studies also suggest magnetic resonance elastography as an alternative to the less reliable ultrasonography.Intensive lifestyle modifications, including physical activity and dietary changes, are the first line of treatment according to AASLD and EASL as it improves the liver histology and aminotransferase levels. In terms of pharmacological treatment, the AASLD and EASL do not recommend metformin, but vitamin E may improve liver health for some children.
These non-invasive methods can be used for NAFLD screening but are not accepted as a substitute for liver biopsy in NAFLD nor NASH clinical trials, as only a liver biopsy can define liver pathology.Ultrasound presented average sensitivity and specificity for diagnosing the disease in children, while in the adult population, sensitivity and specificity were significantly higher. Proton density fat fraction magnetic resonance imaging has been increasingly used for the diagnosis of steatosis in pediatric patients. Elastography is an effective tool for staging liver fibrosis and discriminating NASH from NAFLD in children.CT scans and MRIs are more accurate in detecting cirrhosis than conventional ultrasound. Transient elastography is recommended for the initial assessment of liver fibrosis and cirrhosis and helps to predict complications and prognosis, but the interpretation of results is carefully weighed in the presence of limiting factors, such as steatosis, high BMI, lower degrees of hepatic fibrosis and narrow spaces between the ribs (intercostal spaces). However, transient elastography can fail for people with pre-hepatic portal hypertension. Transient elastography is not considered to be a replacement for liver biopsy.Magnetic resonance elastography (MRE) is an emerging method that can accurately assess hepatic fibrosis and is recommended by the APASL. MRE possesses a good sensitivity to quantify hepatic fat and excellent accuracy to detect fibrosis in NAFLD regardless of BMI and inflammation and is suggested as a more reliable alternative to diagnose NAFLD and its progression to NASH compared to ultrasound and blood tests.