Neonatal hepatitis

A minority of cases, about 20%, are known to be caused by a virus that infected the infant before birth, through the mother, or maybe shortly after birth.

Several viruses that have been known to cause neonatal hepatitis are rubella, cytomegalovirus, and hepatitis viruses A, B and C.

The other 80% of cases are said to be idiopathic, meaning we don’t really know what the underlying cause was, a lot of times viruses are suspected, but it could also be due to other genetic disorders, cholestasis where bile flow is impaired, or metabolic liver disorders like alpha-1 antitrypsin deficiency.

This last one’s an inherited disease in which the alpha-1 antitrypsin or AAT protein that’s produced in the liver is not quite produced right, and is essentially the wrong shape.

When this happens, it can’t get out of the liver cells, ultimately building up and causing liver cell death, inflammation of liver tissue, and hepatitis.

A newborn or infant with neonatal hepatitis will often have jaundice, causing yellowed skin and eyes due to the blockage or inflammation of the bile ducts.

When these are blocked, bilirubin, a yellow pigmented component of bile, builds up in the blood and starts to get into tissues, causing yellowed skin and eyes.

Bile’s an essential part of fat digestion and absorption of fat soluble vitamins like vitamin A, D, E, and K, so children with neonatal hepatitis and jaundice may fail to gain weight and grow normally due to lack of adequate nutrition.

Bile also functions in removing toxins from the body, like bilirubin but also things like drug metabolites, so if bile flow is reduced, these might deposit and build up in the skin and lead to itching and rashes.

Bilirubin might also be filtered into the urine through the kidneys, causing darker colored urine.

Since hepatitis is an inflammation of the liver, patients may also present with an enlarged liver, or hepatomegaly.

Summary

Neonatal hepatitis is a type of liver inflammation that affects newborn babies. It may be caused by a viral infection, such as rubella, cytomegalovirus, and hepatitis viruses A, B, and C. In some cases, the cause may be a problem with the baby's liver (e.g. alpha-1 antitrypsin deficiency), or even unknown sometimes (idiopathic).

Symptoms of neonatal hepatitis may include jaundice (yellowing of the skin and whites of the eyes), dark urine, light stools, swelling of the abdomen, and failure to grow and gain weight at the expected rate. The severity of the symptoms can vary depending on the cause and severity of hepatitis.

Treatment for neonatal hepatitis may include medications to control the inflammation and support the functioning of the liver, as well as supportive care, such as fluid and electrolyte management. In severe cases, a liver transplant may be necessary.

Sources

"Robbins Basic Pathology" Elsevier (2017)

"Harrison's Principles of Internal Medicine" McGraw Hill / Medical (2018)

"Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)

"CURRENT Medical Diagnosis and Treatment 2020" McGraw Hill Professional (2019)

"Neonatal hemochromatosis: A rare cause of liver failure in infancy" Indian Journal of Pathology and Microbiology (2020)

"Neonatal hepatitis syndrome" Seminars in Neonatology (2003)

Neonatal hepatitis

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