Non-alcoholic fatty liver disease in children — structured clinical encounter

Station brief (candidate)

You are the paediatric registrar in a general paediatric clinic. An eleven-year-old boy is reviewed at a routine visit. His body mass index is on the ninety-second percentile. He drinks two cans of sugar-sweetened soft drink a day, plays no organised sport, and spends most evenings on a screen. His alanine aminotransferase is 34 units per litre, and the laboratory reports its normal range as up to 55 units per litre. His father has type 2 diabetes. The team asks you to interpret the result, state the relevant thresholds, outline the confirmation and exclusion pathway, and deliver the management and family-counselling plan. You have twelve minutes with the team and five minutes for examiner discussion. [1]

Information available on request

• Eleven years old, previously well; no abdominal pain, jaundice, or fatigue; normal developmental history. [1]
• Body mass index on the ninety-second percentile; waist circumference increased; acanthosis nigricans at the nape. [1]
• Alanine aminotransferase 34 units per litre; laboratory reference range up to 55 units per litre; aspartate aminotransferase, bilirubin, albumin and coagulation normal. [6]
• Lifestyle: two sugar-sweetened cans daily, fast food three times weekly, no organised sport, four or more hours of daily screen time. [1]
• Family history: father with type 2 diabetes; paternal uncle with known fatty liver disease. [1]

Tasks

1. Interpret the alanine aminotransferase result and explain why the laboratory range may be misleading. [1]
2. State the NASPGHAN 2017 sex-specific upper limits of normal and the screening age band. [1]
3. Outline how you would confirm the diagnosis, the threshold for formal evaluation and referral, and the exclusion workup. [6]
4. Describe your first-line management and the weight-loss target associated with histological improvement. [1]
5. Counsel the family on the outlook, including the leading long-term risk. [8]

Marking anchors

Must-hit

• Recognises that 34 units per litre is abnormal by the NASPGHAN thresholds of 22 units per litre for girls and 26 for boys, which are far lower than the laboratory range, because the laboratory range was derived from a population that included people with undiagnosed fatty liver disease. [1]
• States that screening begins between ages nine and eleven for obesity or overweight with a risk factor, and confirms persistence by repeating the alanine aminotransferase before extensive investigation. [1]
• Outlines the exclusion of autoimmune, viral, Wilson, alpha-1-antitrypsin, drug and metabolic causes when the alanine aminotransferase remains above twice the upper limit of normal for more than three months, and non-invasive staging of fibrosis with elastography. [6]

Merit

• Delivers a family-based lifestyle plan engaging the whole household, targeting a 7 to 10 per cent weight reduction through reduction of sugar-sweetened beverages and fructose, increased fruit, vegetables and fibre, at least one hour of daily moderate to vigorous activity, and reduced sedentary screen time; and frames cardiovascular disease, rather than liver failure, as the leading long-term risk, addressed through sustained weight management and comorbidity control. [8]

Fail

• Accepts the laboratory range as normal and dismisses the result, or starts metformin or another medication as a substitute for lifestyle therapy, or fails to engage the family and the cardiometabolic context in the management plan. [1] [3]