Core Clinical Cases in Paediatrics PDF

11Jaundice Questions Clinical cases Key concepts Answers  122 Jaundice ? Questions for each of the clinical cases Q1: What is the likely differential diagnosis? Q2: What issues in the given history support the diagnosis? Q3: What additional features in the histor...

11Jaundice Questions Clinical cases Key concepts Answers  122 Jaundice ? Questions for each of the clinical cases Q1: What is the likely differential diagnosis? Q2: What issues in the given history support the diagnosis? Q3: What additional features in the history would you seek to support a particular diagnosis? Q4: What clinical examination would you perform, and why? Q5: What investigations would be most helpful, and why? Q6: What treatment options are appropriate? Clinical cases CASE 11.1 – My newborn baby is yellow. A 3-day-old term baby is noted to be yellow by his mother. He is breast-fed and is making slow progress. CASE 11.2 – My 3-week-old baby is still jaundiced. A 3-week-old girl was noted by the health visitor to have persisting jaundice. She is still breast-fed, but has not yet regained her birth weight. CASE 11.3 – My 7-year-old son has developed jaundice. A 7-year-old boy was referred for investigation of malaise, fever and jaundice. He has dark urine and pale stools.  OSCE counselling cases 123 OSCE counselling cases OSCE COUNSELLING CASE 11.1 – Why is my newborn baby yellow? OSCE COUNSELLING CASE 11.2 – I’m worried that my 3-week-old baby is still jaundiced?  124 Jaundice Key concepts In order to work through the core clinical cases in this chapter, you will need to understand the following key concepts. Metabolism of bilirubin z Unconjugated bilirubin is formed following the break-down of erythrocytes, conjugated in the liver by glucuronyl transferase and secreted in bile. In the gut, conjugated bilirubin is further metabolized to urobilinogen (excreted in urine) and stercobilinogen (excreted in faeces). Some is deconjugated and reabsorbed (enterohepatic circulation). Physiological jaundice z Common in newborn babies, and occurs usually between 3–7 days of age. z Precipitating factors include a high postnatal haemoglobin, shorter erythrocyte life span, reduced fluid intake and bruising. In addition, the neonatal liver is less efficient at conjugating bilirubin. z The serum bilirubin is always >90 per cent unconjugated. This condition is self-limiting, and only requires treatment if the serum bilirubin becomes very high (>300 µmol/L in term babies). Pathological jaundice z Any jaundice which is caused by a pathological process. z In the neonate, it can be subdivided into early (2 weeks) jaundice. Early jaundice is likely to be due to erythrocyte haemolysis (e.g. Rhesus isoimmunization, ABO incompatibility, spherocytosis). The serum bilirubin is unconjugated. z A high conjugated component to the serum bilirubin (>15–20%) suggests an obstructive cause (see below). z Breast milk jaundice is a benign cause of prolonged jaundice. Sepsis may cause jaundice in the newborn. Any baby who is jaundiced and unwell should be considered to have a pathological cause, until proved otherwise. Obstructive jaundice z A high conjugated bilirubin, pale stools (lack of stercobilinogen) and dark urine (presence of bilirubin) indicates an obstructive cause which may be either intrahepatic (e.g. hepatitis) or extrahepatic (e.g. biliary atresia). z The conjugated component of total bilirubin should always be checked in any baby with jaundice at more than 2 weeks of age. A delay in the diagnosis of biliary atresia beyond 6 weeks of age reduces the likelihood of successful surgery for that condition (biliary drainage by a Kasai portoenterostomy). z It can be difficult to distinguish clinically between neonatal hepatitis and biliary atresia, and a radionucleotide scan (or occasionally a liver biopsy) is usually indicated. Referral to a specialist paediatric hepatology service is advised. Hepatitis z Neonatal hepatitis can occur in a wide range of disease processes including congenital infections (e.g. toxoplasmosis, cytomegalovirus (CMV)) and metabolic diseases (e.g. alpha-1-antitrypsin deficiency). In older children, Hepatitis A, B and C, glandular fever and CMV infection can cause acute liver inflammation.  Answers 125 Answers CASE 11.1 – My newborn baby is yellow. Q1: What is the likely differential diagnosis? A1 z Physiological jaundice. z Haemolysis. z Sepsis. z Inherited metabolic disorder, e.g. glucose 6-phosphate dehydrogenase (G-6PD) deficiency, galactosaemia. Q2: What issues in the given history support the diagnosis? A2 z The baby is at the age at which physiological jaundice is likely to present. z Breast feeding may lead to reduced fluid intake initially. Some normal babies are slow to establish breast feeding, but this may indicate lethargy and suggest a pathological process such as sepsis. A Q3: What additional features in the history would you seek to support a particular diagnosis? A3 z Ask about feeding activity. Does he suck well? Is the baby pyrexial, excessively sleepy or lethargic? z Has he passed normal urine and stool? Clinical assessment of level of jaundice. z Check maternal blood group and presence of antenatal antibodies (e.g. anti D). z Enquire about previous babies or family history of jaundice. Q4: What clinical examination would you perform, and why? A4 z Assessment of baby’s well-being, check for hepatosplenomegaly and signs of sepsis (lethargy, high-pitched cry, mottling, tense fontanelle).  126 Jaundice Q5: What investigations would be most helpful, and why? A5 z Serum bilirubin. Unconjugated and conjugated. To define degree of jaundice and exclude significant conjugated component. z Blood group and direct antibody test (DAT) or Coombs test (evidence of haemolysis due to ABO incompatibility or Rhesus disease). z Urine for reducing substances (Clinitest), including glucose. To exclude galactosaemia and fructosaemia. z Urine culture (to exclude urinary tract infection, UTI). Q6: What treatment options are appropriate? A6 z In a well baby with no evidence of haemolysis, the most likely cause is physiological jaundice. If the serum bilirubin is 450 µmol/L may cross the blood–brain barrier and cause kernicterus). Phototherapy may be insufficient in this case, and exchange transfusion may be required. z If the urine contains reducing substances (not glucose), exclude galactosaemia and fructosaemia. CASE 11.2 – My 3-week-old baby is still jaundiced. Q1: What is the likely differential diagnosis? A1 z Breast milk jaundice. z Urinary tract infection (UTI). z Neonatal hepatitis. z Extrahepatic biliary atresia. Q2: What issues in the given history support the diagnosis? A2 The baby is receiving breast milk and is too old for physiological or haemolytic jaundice. The baby’s weight gain is poor, which suggests either inadequate intake or a pathological process.  Answers 127 A Q3: What additional features in the history would you seek to support a particular diagnosis? A3 z Ask about feeding activity and weight gain in more detail. z Is the baby pyrexial, excessively sleepy or lethargic? z Enquire about the colour of urine and stool. Is the urine smelly? (a fishy smell may occur with UTI) z Clinical assessment of level of jaundice. z Enquire about previous babies or family history of jaundice. Q4: What clinical examination would you perform, and why? A4 General examination, assessment of well-being. Re-check weight, examine for hepatosplenomegaly. Q5: What investigations would be most helpful, and why? A5 z Serum bilirubin. Unconjugated and conjugated. To define degree of jaundice and exclude significant conjugated component. z If normal conjugated component and normal stools/urine, check urine for reducing substances and culture. z If high conjugated component, check liver function tests (AST, ALT, γ-GT), TORCH screen (for Toxoplasma, Rubella, Cytomegalovirus, Herpes simplex) α-1- antitrypsin phenotype. z Radionucleotide excretion scan to assess biliary excretion. Q6: What treatment options are appropriate? A6 z If normal conjugated component and normal stools/urine. Advise regarding breast-feeding and milk intake; re-weigh regularly until thriving. z Conjugated jaundice – urgent referral to paediatric hepatologist for further assessment and diagnosis.  128 Jaundice Case 11.3 – My 7-year-old son has developed jaundice. Q1: What is the likely differential diagnosis? A1 z Viral hepatitis (A, B or C). z Infectious mononucleosis (glandular fever). z Cytomegalovirus infection. z Wilson’s disease. z Chronic active hepatitis. Q2: What issues in the given history support the diagnosis? A2 z The combination of jaundice, dark urine and pale stools suggest acute liver inflammation. z Malaise and fever suggest an infective process. A Q3: What additional features in the history would you seek to support a particular diagnosis? A3 z Ask about prodromal illness with anorexia, abdominal pain, diarrhoea and vomiting. z Also ask about sore throat (glandular fever). z Check recent travel abroad, illness in close contacts and family history. Q4: What clinical examination would you perform, and why? A4 z Examine abdomen for tender hepatomegaly ± splenomegaly. z Examine eyes for Kayser Fleischer rings (Wilson’s disease). z Check for lymph node enlargement (glandular fever).  Answers 129 Q5: What investigations would be most helpful, and why? A5 z Hepatitis A IgM antibodies: if negative consider: z Hepatitis B sAg; z Blood film for atypical mononuclear cells and monospot test Epstein–Barr virus IgM antibodies (glandular fever); z Cytomegalovirus (CMV) IgM; z Serum immunoglobulins and tissue autoantibodies (chronic active hepatitis); and z Serum caeruloplasmin and urinary copper (Wilson’s disease). Q6: What treatment options are appropriate? A6 z If the diagnosis is hepatitis A or B, glandular fever or CMV infection, then no specific treatment is indicated. z The rare condition of Wilson’s disease may need treatment with penicillamine. z In hepatitis C or chronic active hepatitis the patient should be referred to a hepatologist.  130 Jaundice OSCE counselling cases OSCE COUNSELLING CASE 11.1 – Why is my newborn baby yellow? The baby has physiological jaundice. This is a common condition, but it can cause parental anxiety. z Physiological jaundice is a self-limiting condition. Most babies with this condition do not need treatment, but should be encouraged to drink plenty of fluid. Occasionally, the jaundice level reaches a point which requires intervention, and the most usual treatment is phototherapy (blue light which breaks down bilirubin into harmless metabolites), usually for a day or so. z The reasons that babies become jaundiced is usually because their blood count (haemoglobin, Hb) is high and Hb is broken down to bilirubin. Newborn babies’ blood cells are broken down faster than those of adults, and their livers in the first few days of life cannot metabolize the bilirubin as efficiently. Newborn babies also tend to take less fluid in the first day or so of life, and may have bruises from the delivery. These factors may also contribute to jaundice. z A simple heel prick blood test will indicate the level of jaundice and the need for treatment. Other simple routine tests may also be performed to exclude other causes of jaundice (e.g. urinalysis, blood group and Coombs’ test). z If the baby is unwell, then the cause of jaundice is unlikely to be physiological and further urgent investigations may be necessary. OSCE COUNSELLING CASE 11.2 – I’m worried that my 3-week-old baby is still jaundiced? The baby is well, afebrile and breast feeding well with good weight gain. Examination is normal and the stool and urine are normal colour. The serum bilirubin is all unconjugated. z The commonest cause for prolonged jaundice is breast milk jaundice. However, there is not a specific test that we can do to confirm this, so we need to consider other important causes. That is why we have asked you about your baby and performed a blood test. z Bilirubin forms bile which is normally broken down in the intestines, and it is this that make stools a yellow or brown colour. In a very serious condition where the bile cannot get into the intestines, bilirubin builds up in the blood and can pass out in the urine, making it turn dark brown. The combination of pale stools (like putty) and dark urine should alert us that there is a problem. It is important that this condition (biliary atresia) is treated as soon as possible before irreversible damage occurs in the liver. That your baby’s stools and urine are normal colour and the blood test shows only one type of bilirubin (unconjugated) is very reassuring. z Sometimes an infection (particularly of the urine) can cause jaundice. The fact that your baby is well, does not have a fever, is feeding well and thriving makes this unlikely. z By far the most likely cause is jaundice from breast milk. This is common, harmless and needs no treatment. It usually resolves in 2–3 weeks. The presence of a substance (α-glucuronidase) in the breast milk leads to a slight increase in the absorption of bilirubin back from the intestine (by deconjugating bilirubin in the bowel and increasing enterohepatic circulation). z There is no need to stop breast feeding to confirm the diagnosis. This will only deprive your baby of the important nutrients and substances which improve immunity that breast milk contains.