Conditions Flashcards
Retinoblastoma
Retinoblastoma is the most common ocular malignancy found in children. The average age of diagnosis is 18 months.
Pathophysiology
autosomal dominant
caused by a loss of function of the retinoblastoma tumour suppressor gene on chromosome 13
around 10% of cases are hereditary
Possible features
absence of red-reflex, replaced by a white pupil (leukocoria) - the most common presenting symptom
strabismus
visual problems
Management
enucleation is not the only option
depending on how advanced the tumour is other options include external beam radiation therapy, chemotherapy and photocoagulation
Prognosis
excellent, with > 90% surviving into adulthood
Cot Death/SIDS
Sudden infant death syndrome is the commonest cause of death in the first year of life. It is most common at 3 months of age.
Major risk factors
putting the baby to sleep prone: the relative risk or odds ratio varies from 3.5 - 9.3. If not accustomed to prone sleeping (i.e. the baby usually sleeps on their back) the odds ratio increases to 8.7-45.4
parental smoking: studies suggest this increases the risk up to 5 fold
prematurity: 4-fold increased risk
bed sharing: odds ratio 5.1
hyperthermia (e.g. over-wrapping) or head covering (e.g. blanket accidentally moves)
Other risk factors
male sex
multiple births
social classes IV and V
maternal drug use
incidence increases in winter
It is important to remember that these odds are additive. For example, if both parents smoke, the mother had consumed two units of alcohol and they then shared a bed with the infant the adjusted odds ratio was shown to be 89.7.
Protective factors
breastfeeding
room sharing (but not bed sharing, which is a significant risk factor)
the use of dummies (pacifiers)
Following a cot death siblings should be screened for potential sepsis and inborn errors of metabolism.
Biliary Atresia
Biliary atresia is a paediatric condition involving either obliteration or discontinuity within the extrahepatic biliary system, which results in an obstruction in the flow of bile. This results in a neonatal presentation of cholestasis in the first few weeks of life. The pathogenesis of biliary atresia is unclear, however, infectious agents, congenital malformations and retained toxins within the bile are all contributing factors.
Epidemiology
Extrahepatic biliary atresia is more common in females than males
Biliary atresia is unique to neonatal children: The perinatal form presents in the first two weeks of life, and the postnatal form presents within the first 2-8 weeks of life
Biliary atresia occurs in 1 in every 10,000-15,000 live births
Types:
Type 1: The proximal ducts are patent, however, the common duct is obliterated
Type 2: There is atresia of the cystic duct and cystic structures are found in the porta hepatis
Type 3: There is atresia of the left and right ducts to the level of the porta hepatis, this occurs in >90% of cases of biliary atresia
Patients typically present in the first few weeks of life with:
Jaundice extending beyond the physiological two weeks
Dark urine and pale stools
Appetite and growth disturbance, however, may be normal in some cases
Signs:
Jaundice
Hepatomegaly with splenomegaly
Abnormal growth
Cardiac murmurs if associated cardiac abnormalities present
Investigations:
Serum bilirubin including differentiation into conjugated and total bilirubin: Total bilirubin may be normal, whereas conjugated bilirubin is abnormally high
Liver function tests (LFTs) including serum bile acids and aminotransferases are usually raised but cannot differentiate between biliary atresia and other causes of neonatal cholestasis
Serum alpha 1-antitrypsin: Deficiency may be a cause of neonatal cholestasis
Sweat chloride test: Cystic fibrosis often involves the biliary tract
Ultrasound of the biliary tree and liver: May show distension and tract abnormalities
Percutaneous liver biopsy with intraoperative cholangioscopy
Management:
Surgical intervention is the only definitive treatment for biliary atresia: Intervention may include dissection of the abnormalities into distinct ducts and anastomosis creation
Medical intervention includes antibiotic coverage and bile acid enhancers following surgery
Complications:
Unsuccessful anastomosis formation
Progressive liver disease
Cirrhosis with eventual hepatocellular carcinoma
Prognosis:
Prognosis is good if surgery is successful
In cases where surgery fails, liver transplantation may be required in the first two years of life
Stridor
Causes of stridor in children include:
Croup Croup is a form of upper respiratory tract infection seen in infants and toddlers. It is characterised by stridor which is caused by a combination of laryngeal oedema and secretions. Parainfluenza viruses account for the majority of cases.
Epidemiology
peak incidence at 6 months - 3 years
more common in autumn
Features
stridor
barking cough (worse at night)
fever
coryzal symptoms
Acute epiglottitis Acute epiglottitis is rare but serious infection caused by Haemophilus influenzae type B. Prompt recognition and treatment is essential as airway obstruction may develop. Epiglottitis generally occurs in children between the ages of 2 and 6 years. The incidence of epiglottitis has decreased since the introduction of the Hib vaccine
Features
rapid onset
unwell, toxic child
stridor
drooling of saliva
Inhaled foreign body Symptoms depend on the site of impaction
Features are of sudden onset
coughing
choking
vomiting
stridor
Laryngomalacia Congenital abnormality of the larynx.
Infants typical present at 4 weeks of age with:
stridor
Foot Drop
Foot drop is a result of weakness of the foot dorsiflexors.
Possible causes include:
common peroneal nerve lesion - the most common cause
L5 radiculopathy
sciatic nerve lesion
superficial or deep peroneal nerve lesion
other possible includes central nerve lesions (e.g. stroke) but other features are usually present
A common peroneal nerve lesion is the most common cause . This is often secondary to compression at the neck of the fibula. This may be caused by certain positions such as leg crossing, squatting or kneeling. Prolonged confinement, recent weight loss, Baker’s cysts and plaster casts to the lower leg are also known to be precipitating factors.
Examination
if the patient has an isolated peroneal neuropathy there will be weakness of foot dorsiflexion and eversion. Reflexes will be normal
weakness of hip abduction is suggestive of a L5 radiculopathy
Bilateral symptoms, fasiculations or other abnormal neurological findings (e.g. hyperreflexia) are indications for specialist referral.
If the examination suggests a peroneal neuropathy then conservative management is appropriate. Leg crossing, squatting and kneeling should be avoided. Symptoms typically improve over 2-3 months.*
Bites
Animal bites
The majority of bites seen in everyday practice involve dogs and cats. These are generally polymicrobial but the most common isolated organism is Pasteurella multocida.
Management
cleanse wound. Puncture wounds should not be sutured closed unless cosmesis is at risk
current BNF recommendation is co-amoxiclav
if penicillin-allergic then doxycycline + metronidazole is recommended
Human bites
Human bites commonly cause multimicrobial infection, including both aerobic and anaerobic bacteria.
Common organisms include:
Streptococci spp.
Staphylococcus aureus
Eikenella
Fusobacterium
Prevotella
Co-amoxiclav is recommended, as for animal bites.
The risk of viral infections such as HIV and hepatitis C should also be considered.
Pancytopenia
deficiency of all three cellular components of the blood (red cells, white cells, and platelets).
Pancytopenia may be caused by certain autoimmune, bone marrow, or genetic disorders. It may also be caused by infection, poor nutrition, pregnancy, cancer treatment (such as chemotherapy or radiation therapy), or exposure to certain toxins, chemicals, or medicines.
Prematurity
Prematurity is defined as birth before 37 weeks gestation. Many successful and famous people were born prematurely, including Albert Einstein. The more premature the baby, the worse the outcomes. Resuscitation in babies under 500 grams or 24 weeks gestation should be carefully considered, as outcomes are likely to be very poor.
The WHO classify prematurity as:
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
Associations
Social deprivation
Smoking
Alcohol
Drugs
Overweight or underweight mother
Maternal co-morbidities
Twins
Personal or family history of prematurity
Management Before Birth
There is a dramatic improvement in prognosis with each additional week of gestation, particularly in very premature babies. In women with a history of preterm birth or an ultrasound demonstrating a cervical length of 25mm or less before 24 weeks gestation there are two options of trying to delay birth:
Prophylactic vaginal progesterone: putting a progesterone suppository in the vagina to discourage labour
Prophylactic cervical cerclage: putting a suture in the cervix to hold it closed
Where preterm labour is suspected or confirmed there are several options for improving the outcomes:
Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
IV Magnesium sulphate: can be offered before 34 weeks gestation and helps protect the baby’s brain
Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby
Issues In Early Life
Respiratory distress syndrome
Hypothermia
Hypoglycaemia
Poor feeding
Apnoea and bradycardia
Neonatal jaundice
Intraventricular haemorrhage
Retinopathy of prematurity
Necrotising enterocolitis
Immature immune system and infection
Long Term Effects
Chronic lung disease of prematurity (CLDP)
Learning and behavioural difficulties
Susceptibility to infections, particularly respiratory tract infections
Hearing and visual impairment
Cerebral palsy
Apnoea of Prematurity
Apnoea are defined as periods where breathing stops spontaneously for more than 20 seconds, or shorter periods with oxygen desaturation or bradycardia. Apnoea can occur in neonates of all gestational ages. They are often accompanied by a period of bradycardia.
Apnoea is very common in premature neonates. They occur in almost all babies less than 28 weeks gestation and the incidence decreases with increased gestational age. In term infants apnoea usually indicate underlying pathology.
Causes
Apnoea occur due to immaturity of the autonomic nervous system that controls respiration and heart rate. This system is more immature in premature neonates.
Apnoea are often a sign of developing illness, such as:
Infection
Anaemia
Airway obstruction (may be positional)
CNS pathology, such as seizures or haemorrhage
Gastro-oesophageal reflux
Neonatal abstinence syndrome
Management
Neonatal units attach apnoea monitors to premature babies. These make a sound when an apnoea is occurring. Tactile stimulation is used to prompt the baby to restart breathing. Intravenous caffeine can be used to prevent apnoea and bradycardia in babies with recurrent episodes.
Episodes will settle as as the baby grows and develops.
Retinopathy of Prematurity
Retinopathy of prematurity is a condition affecting preterm and low birth weight babies. It typically affects babies born before 32 weeks gestation. Abnormal development of the blood vessels in the retina can lead to scarring, retinal detachment and blindness. Treatment can prevent blindness, which is why screening is so important.
Pathophysiology
Retinal blood vessel development starts at around 16 weeks and is complete by 37 – 40 weeks gestation. The blood vessels grow from the middle of the retina to the outer area. This vessel formation is stimulated by hypoxia, which is a normal condition in the retina during pregnancy. When the retina is exposed to higher oxygen concentrations in a preterm baby, particularly with supplementary oxygen during medical care, the stimulant for normal blood vessel development is removed.
When the hypoxic environment recurs, the retina responds by producing excessive blood vessels (neovascularisation), as well as scar tissue. These abnormal blood vessels may regress and leave the retina without a blood supply. The scar tissue may cause retinal detachment.
Assessment
The retina is divided into three zones:
Zone 1 includes the optic nerve and the macula
Zone 2 is from the edge of zone 1 to the ora serrata, the pigmented border between the retina and ciliary body
Zone 3 is outside the ora serrata
The retinal areas are described as a clock face, for example “there is disease from 3 to 5 o’clock”. The areas of disease are described from stage 1 (slightly abnormal vessel growth) to stage 5 (complete retinal detachment).
“Plus disease” describes additional findings, such as tortuous vessels and hazy vitreous humour.
Screening
Babies born before 32 weeks or under 1.5kg should be screened for ROP. Screening is performed by an ophthalmologist. Screening starts at:
30 – 31 weeks gestational age in babies born before 27 weeks
4 – 5 weeks of age in babies born after 27 weeks
Screening should happen at least every 2 weeks and can cease once the retinal vessels enter zone 3, usually at around 36 weeks gestation.
Examination
All retinal areas need to be visualised. Screening involves monitoring the retinal vessels as they develop and looking for plus disease.
Treatment
Treatment involves systematically targeting areas of the retina to stop new blood vessels developing.
First line is transpupillary laser photocoagulation to halt and reverse neovascularisation.
Other options are cryotherapy and injections of intravitreal VEGF inhibitors. Surgery may be required if retinal detachment occurs.
GOR in Children
Gastro-oesophageal reflux is where contents from the stomach reflux through the lower oesophageal sphincter into the oesophagus, throat and mouth.
In babies there is immaturity of the lower oesophageal sphincter, allowing stomach contents to easily reflux into the oesophagus. It is normal for a baby to reflux feeds, and provided there is normal growth and the baby is otherwise well this is not a problem, however it can be upsetting for parents. This usually improves as they grow and 90% of infants stop having reflux by 1 year.
Presentation
It is normal for babies to have some reflux after larger feeds. It becomes more troublesome when this causes them to become distressed. Signs of problematic reflux include:
Chronic cough
Hoarse cry
Distress, crying or unsettled after feeding
Reluctance to feed
Pneumonia
Poor weight gain
Children over one year may experience similar symptoms to adults, with heartburn, acid regurgitation, retrosternal or epigastric pain, bloating and nocturnal cough.
Causes of Vomiting
Vomiting is very non-specific and is often not indicative of underlying pathology. Some of the possible causes of vomiting include:
Overfeeding
Gastro-oesophageal reflux
Pyloric stenosis (projective vomiting)
Gastritis or gastroenteritis
Appendicitis
Infections such as UTI, tonsillitis or meningitis
Intestinal obstruction
Bulimia
Red Flags
Certain features in the history should make you think about serious underlying problems:
Not keeping down any feed (pyloric stenosis or intestinal obstruction)
Projectile or forceful vomiting (pyloric stenosis or intestinal obstruction)
Bile stained vomit (intestinal obstruction)
Haematemesis or melaena (peptic ulcer, oesophagitis or varices)
Abdominal distention (intestinal obstruction)
Reduced consciousness, bulging fontanelle or neurological signs (meningitis or raised intracranial pressure)
Respiratory symptoms (aspiration and infection)
Blood in the stools (gastroenteritis or cows milk protein allergy)
Signs of infection (pneumonia, UTI, tonsillitis, otitis or meningitis)
Rash, angioedema and other signs of allergy (cows milk protein allergy)
Apnoeas are a concerning feature and may indicate serious underlying pathology and need urgent assessment
Management
In simple cases some explanation, reassurance and practical advice is all that is needed. Advise:
Small, frequent meals
Burping regularly to help milk settle
Not over-feeding
Keep the baby upright after feeding (i.e. not lying flat)
More problematic cases can justify treatment with
Gaviscon mixed with feeds
Thickened milk or formula (specific anti-reflux formulas are available)
Proton pump inhibitors (e.g., omeprazole) where other methods are inadequate
Rarely in severe cases they may need further investigation with a barium meal and endoscopy. Surgical fundoplication can be considered in very severe cases, however this is very rarely required or performed.
Sandifer’s Syndrome
This is a rare condition causing brief episodes of abnormal movements associated with gastro-oesophageal reflux in infants. The infants are usually neurologically normal. The key features are:
Torticollis: forceful contraction of the neck muscles causing twisting of the neck
Dystonia: abnormal muscle contractions causing twisting movements, arching of the back or unusual postures
The condition tends to resolve as the reflux is treated or improves. Generally the outcome is good. It is worth referring patients with these symptoms to a specialist for assessment, as the differential diagnosis includes more serious conditions such as infantile spasms (West syndrome) and seizures.
Pyloric Stenosis
The pyloric sphincter is a ring of smooth muscle the forms the canal between the stomach and the duodenum. Hypertrophy (thickening) and therefore narrowing of the pylorus is called pyloric stenosis. This prevents food traveling from the stomach to the duodenum as normal.
After feeding, there is increasingly powerful peristalsis in the stomach as it tries to push food into the duodenum. Eventually it becomes so powerful that it ejects the food into the oesophagus, out of the mouth and across the room. This is called “projectile vomiting”.
Features
Pyloric stenosis typically presents in the first few weeks of life, with a hungry baby that is thin, pale and generally failing to thrive. The classic description of vomiting you should remember for your exams is “projectile vomiting”.
If examined after feeding, often the peristalsis can be seen by observing the abdomen. A firm, round mass can be felt in the upper abdomen that “feels like a large olive”. This is caused by the hypertrophic muscle of the pylorus.
Blood gas analysis will show a hypochloric (low chloride) metabolic alkalosis as the baby is vomiting the hydrochloric acid from the stomach. This is a common data interpretation question in exams, so worth remembering.
Management
Diagnosis is made using an abdominal ultrasound to visualise the thickened pylorus.
Treatment involves a laparoscopic pyloromyotomy (known as “Ramstedt’s operation“). An incision is made in the smooth muscle of the pylorus to widen the canal allowing that food to pass from the stomach to the duodenum as normal. Prognosis is excellent following the operation.
Hirsprung Disease
Hirschsprung’s disease is a congenital condition where nerve cells of the myenteric plexus are absent in the distal bowel and rectum. The myenteric plexus, also known as Auerbach’s plexus, forms the enteric nervous system. It is the brain of the gut.
This nerve plexus runs all the way along the bowel in the bowel wall, and is a complex web of neurones, ganglion cells, receptors, synapses and neurotransmitters. It is responsible for stimulating peristalsis of the large bowel. Without this stimulation the bowel looses it’s motility and stops being able to pass food along its length.
The key pathophysiology in Hirschsprung’s disease is the absence of parasympathetic ganglion cells. During fetal development these cells start higher in the GI tract and gradually migrate down to the distal colon and rectum. Hirschsprung’s occurs when the parasympathetic ganglion cells do not travel all the way down the colon, and a section of colon at the end is left without these parasympathetic ganglion cells.
The length of colon without innervation varies between patients from a small area to the entire colon. When the entire colon is affected this is called total colonic aganglionosis. The aganglionic section of colon does not relax, causing it to becomes constricted. This leads to loss of movement of faeces and obstruction in the bowel. Proximal to the obstruction the bowel becomes distended and full.
Genetics and Associations
There are a number of genes on various chromosomes that may have a modifying effect to increase the risk of Hirschsprung’s. A family history of Hirschsprung’s greatly increases the risk. Therefore where you are considering a diagnosis of Hirschsprung’s always take a careful family history.
Hirschsprung’s disease usually occurs in isolation, however it is associated with a number of other syndromes, including:
Downs syndrome
Neurofibromatosis
Waardenburg syndrome (a genetic condition causing pale blue eyes, hearing loss and patches of white skin and hair)
Multiple endocrine neoplasia type II
Presentation
The severity of the presentation and the age at diagnosis varies significantly depending on the individual and the extent of the bowel that is affected. It can present with acute intestinal obstruction shortly after birth or more gradually developing symptoms:
Delay in passing meconium (more than 24 hours)
Chronic constipation since birth
Abdominal pain and distention
Vomiting
Poor weight gain and failure to thrive
Hirschsprung-Associated Enterocolitis
Hirschsprung-associated enterocolitis (HAEC) is inflammation and obstruction of the intestine occurring in around 20% of neonates with Hirschsprung’s disease. It typically presents within 2-4 weeks of birth with fever, abdominal distention, diarrhoea (often with blood) and features of sepsis. It is life threatening and can lead to toxic megacolon and perforation of the bowel. It requires urgent antibiotics, fluid resuscitation and decompression of the obstructed bowel.
Management
Abdominal xray can be helpful in diagnosing intestinal obstruction and demonstrating features of HAEC.
Rectal biopsy is used to confirm the diagnosis. The bowel histology will demonstrates an absence of ganglionic cells.
Unwell children and those with enterocolitis will require initial fluid resuscitation and management of the intestinal obstruction. IV antibiotics are required in HAEC.
Definitive management is by surgical removal of the aganglionic section of bowel. Most patients will live a normal life after corrective surgery, although they can have long term disturbances in bowel function and may be left with some degree of incontinence.
Non haemolytic febrile reaction - blood transfusion reaction
Non-haemolytic febrile reaction
Thought to be caused by antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage Fever, chills
Red cell transfusion (1-2%)
Platelet transfusion (10-30%) Slow or stop the transfusion
Paracetamol
Monitor
Minor Allergic Reaction to Blood
Minor allergic reaction
Thought to be caused by foreign plasma proteins Pruritus, urticaria Temporarily stop the transfusion
Antihistamine
Monitor
