2025 – PAGE 229 – GASTROENTEROLOGY
HEPATITIS A
The incubation period of hepatitis A is approximately 4–6 weeks. Children may be asymptomatic (symptoms are much worse in adults). Jaundice can relapse for up to one year.
- PEARLS: Look for a child with elevated transaminases, recent travel, and what sounds like a viral syndrome. DO NOT OBTAIN AN IgG LEVEL FOR DIAGNOSIS. It is persistent for life. Diagnose with IgM. Also, keep in mind that many viral syndromes can cause a mild transaminitis. In viral hepatitis, look for elevation in the many hundreds to thousands.
HEPATITIS B
Hepatitis B SURFACE ANTIGEN (HBsAg) persistence beyond 6 months means there is a chronic infection. HEPATITIS B “E” ANTIGEN (HBeAg) presence means there is high replication resulting in a high viral load and high infectivity. The WINDOW PERIOD is the period after the Hep B surface Ag presents and before the Hep B surface Abs (anti-HBs) are made. Diagnosis during this time can be difficult UNLESS anti-HBc (IgM, anti-core antibody) is obtained. If this test is positive and everything else is negative, then this is the WINDOW PERIOD.
If the IgG antibodies to core and surface antigens are both positive, this represents a PAST INFECTION (not immunization). If only anti-HBs is positive, that represents prior immunization.
- IMAGE: www.pbrlinks.com/HEPATITISB1
- IMAGE:www.pbrlinks.com/HEPBSEROLOGY
- PEARL: Vertical transmission is a very common mode of transmission.
- MNEMONIC: HBeAg reflects high “Enfectivity”
HEPATITIS C
Hepatitis C is the most common blood-borne infection in the U.S. and the most common etiology of chronic viral hepatitis. Kids with Hep C are mostly asymptomatic. Symptoms show later with liver CA and cirrhosis.
GILBERT’S SYNDROME (AKA GILBERTS SYNDROME)
In Gilbert’s Syndrome, there is a glucuronyl transferase deficiency (therefore conjugation of bilirubin is decreased). It’s the most common inherited cause of indirect hyperbilirubinemia. The intermittent indirect hyperbilirubinemia is mild (usually with levels < 3), extremely common, and BENIGN. It is usually autosomal recessive. It is usually noted at times of illness and physiologic stress (dehydration, fasting, and even in vigorous exercise).
MNEMONIC: gIlBert’s. The “I” represents Indirect. The “B” represents both Bilirubinemia and the fact that this is a Benign condition.
CRIGLER-NAJJAR SYNDROME
In Crigler-Najjar Syndrome, there is a glucuronyl transferase deficiency (therefore conjugation of bilirubin is decreased). This results in indirect hyperbilirubinemia and is rare.
- TYPE 1: NO DIRECT BILIRUBIN (zero) because of a complete lack of glucuronyl transferase. There is severe INDIRECT hyperbilirubinemia and jaundice within the first days of life. Type 1 requires lifelong phototherapy.
- TYPE 2: Glucuronyl transferase function partially exists, so patients do well with the partial conjugation indirect to direct bilirubin. They do not need phototherapy.
MNEMONIC: Najjar sounds like NINJA. Imaging two ninjas born to a man named Craig. The first-born carries 1 sword (Type 1) and is always seen wearing protective goggles because he’ll need life-long phototherapy to protect himself.
MNEMONIC: (image)
PEARL: There is more severe loss if the enzyme in Crigler-Najjar syndrome than there is in Gilbert’s syndrome.