What is an expected clinical feature in an infant with jaundice and an enlarged fontanelle?

In the context of an infant presenting with jaundice and an enlarged fontanelle, hypotonia is a significant clinical feature. Jaundice in infants is often associated with bilirubin elevation, which can arise from various causes, including hemolytic disease, liver dysfunction, or obstructive jaundice. The enlarged fontanelle can indicate increased intracranial pressure or other neurological issues.

Hypotonia, or decreased muscle tone, can occur in conjunction with underlying neurological complications that may accompany significant elevations in bilirubin or as a result of conditions present during the infant’s development. For example, kernicterus, which is a severe form of bilirubin toxicity that may cause neurological damage, can result in hypotonia. Additionally, neurologic conditions can lead to issues with muscle control and strength.

In contrast, hyperactivity, dehydration, and constipation are less likely to directly relate to the combination of jaundice and an enlarged fontanelle. Hyperactivity typically isn't observed in infants, especially those presenting with potential neurological concerns. Dehydration is not a direct characteristic associated with either jaundice or an enlarged fontanelle and is often evaluated separately. Constipation involves gastrointestinal issues that wouldn't inherently connect to the observed symptoms of jaundice and an enlarged fontanel