Clinical symptoms vary according to the cause of ALF and the age of the child. In the newborn, the clinical presentation depends on the etiology of neonatal liver failure. Presentation at birth implies an intrauterine insult such as a congenital infection, neonatal hemochromatosis or mitochondrial disorders.
A later presentation may be related to a bacterial or a viral infection or a metabolic condition unveiled by the introduction of feeding (i.e., galactosemia, hereditary fructose intolerance or hereditary tyrosinemia type 1).
A detailed family history, including information on consanguinity, previous miscarriages, neonatal deaths and liver disease in siblings is important to record. Early symptoms are nonspecific, sometimes only related to an altered general condition, poor feeding, lethargy, failure to thrive and vomiting.
Jaundice is inconstant, especially when inborn metabolic diseases are involved. Encephalopathy can be a late feature and is particularly difficult to diagnose in neonates. Behavioral changes, irritability and reversal of day/night sleep patterns indicate hepatic encephalopathy. Convulsions may reflect meningoencephalitic involvement or may be related to hypoglycemia. Hepatomegaly is most often present. Splenomegaly and ascites are usually noted in cases of severe diseases progressing to cirrhosis.
The diagnosis of ALF must be considered in any neonate with coagulopathy. Hypoglycemia and hyperammonemia are common, although these may be related to the underlying disease. High serum transaminases usually result from hepatocyte necrosis associated with acute viral infections, toxic or ischemic injury. By contrast, there is normal-to-moderate elevation of transaminases and minimal-to-moderate jaundice in metabolic liver diseases.