Pathology Part 2 Flashcards
Homocystinuria
A rare autosomal recessive disease caused by a deficiency of cystathionine beta synthase. This results in severe elevations in plasma and urine homocysteine concentrations.
Features of Homocystinuria
> often patients have fine, fair hair
Marfanoid body habitus: arachnodactyly
kyphosis
may have learning difficulties, seizures
downwards dislocation of lens
severe myopia
increased risk of arterial and venous thromboembolism
also malar flush, livedo reticularis
Arachnodactyly
Spidery fingers, and describes the long, slender fingers typical of patients with Marfan syndrome (MFS).
kyphosis
A curvature of the spine measuring 50 degrees or greater on an X-ray,
Investigations for Homocystinuria
- increased homocysteine levels in serum and urine
2. cyanide-nitroprusside test: also +ve in cystinuria
Treatment for Homocystinuria
Vitamin B6 (pyridoxine) supplements
Infantile colic
It typically occurs in infants less than 3 months old and is characterised by bouts of excessive crying and pulling-up of the legs, often worse in the evening.
Infantile spasms
A type of childhood epilepsy which typically presents in the first 4 to 8 months of life and is more common in male infants. They are often associated with a serious underlying condition and carry a poor prognosis
Infantile spasms features
Characteristic ‘salaam’ attacks
Progressive mental handicap
Salaam attacks
Seen in Infantile spasms
Flexion of the head, trunk and arms followed by extension of the arms - lasts only 1-2 seconds but may be repeated up to 50 times
Investigations for Infantile spasms
- EEG shows hypsarrhythmia in two-thirds of infants
2. CT demonstrates diffuse or localised brain disease in 70% (e.g. tuberous sclerosis)
Infantile spasms management
> poor prognosis
vigabatrin is now considered first-line therapy
ACTH is also used
Vigabatrin
Anti-epileptic drug
Inhibits the GABA-degrading enzyme, GABA transaminase, resulting in a widespread increase in GABA concentrations in the brain.
Still’s murmur
Innocent murmur
Low-pitched sound heard at the lower left sternal edge
Venous hums
Innocent murmur - Due to the turbulent blood flow in the great veins returning to the heart. Heard as a continuous blowing noise heard just below the clavicles
Innocent murmurs
Are ejection murmurs including the Still’s murmur and Venous hums
Characteristics of an innocent ejection murmurs
- soft-blowing murmur in the pulmonary area
- short buzzing murmur in the aortic area
- may vary with posture
- localised with no radiation
- no diastolic component
- no thrill
- no added sounds (e.g. clicks)
- asymptomatic child
- no other abnormality
Intraventricular haemorrhage
A haemorrhage that occurs into the ventricular system of the brain. In premature neonates it may occur spontaneously. The blood may clot and occlude CSF flow, hydrocephalus may result.
What is the time-frame for development of intraventricular hemorrhage in neonates?
In the first 72 hours after birth
Intussusception
Describes the invagination of one portion of bowel into the lumen of the adjacent bowel, most commonly around the ileo-caecal region.
What is the time-frame for development of Intussusception?
Infants between 6-18 months old.
Boys are affected twice as often as girls
Features of Intussusception
- Paroxysmal abdominal colic pain
- During paroxysm the infant will characteristically draw their knees up and turn pale
- Vomiting
- Bloodstained stool - ‘red-currant jelly’ - is a late sign
- Sausage-shaped mass in the right upper quadrant
Investigation for Intussusception
Ultrasound - show a target-like mass
Management of Intussusception
> Reduction by air insufflation under radiological control,
If fails, or signs of peritonitis, surgery is performed
Causes of Jaundice in the first 24 hours of life
Always pathological
- rhesus haemolytic disease
- ABO haemolytic disease
- hereditary spherocytosis
- glucose-6-phosphodehydrogenase
Jaundice in the neonate from 2-14 days
Common (up to 40%) and usually physiological.
Physiological jaundice
Jaundice in the neonate from 2-14 days - common
Causes of Prolonged Jaundice >14 days
- biliary atresia
- hypothyroidism
- galactosaemia
- urinary tract infection
- breast milk jaundice
- prematurity - due to immature liver function
- congenital infections e.g. CMV, toxoplasmosis
Investigations for prolonged jaundice
> conjugated and unconjugated bilirubin: the most important test as a raised conjugated bilirubin could indicate biliary atresia which requires urgent surgical intervention
> direct antiglobulin test (Coombs' test) > TFTs > FBC and blood film > urine for MC&S and reducing sugars > U&Es and LFTs
Important diagnostic investigation for Biliary atresia
Conjugated and unconjugated bilirubin: the most important test as a raised conjugated bilirubin could indicate biliary atresia which requires urgent surgical intervention
Juvenile idiopathic arthritis (JIA)
Now preferred to the older term juvenile chronic arthritis, describes arthritis occurring in someone who is less than 16 years old that lasts for more than 6 weeks.
Pauciarticular JIA
Refers to cases where 4 or less joints are affected. It accounts for around 60% of cases of JIA
Features of systemic onset JIA
- pyrexia
- salmon-pink rash
- lymphadenopathy
- arthritis
- uveitis
- anorexia and weight loss
Investigations for JIA
ANA may be positive
Rheumatoid factor is usually negative
Kawasaki disease
A type of vasculitis which is predominately seen in children.
Features of Kawasaki disease
- high-grade fever which lasts for > 5 days.
- Fever is characteristically resistant to antipyretics
- conjunctival injection
- bright red, cracked lips
- strawberry tongue
- cervical lymphadenopathy
- red palms on hands and soles of feet which later peel
Management of Kawasaki disease
- high-dose aspirin
2. intravenous immunoglobulin
Why is aspirin contraindicated in children usually?
Due to the risk of Reye’s syndrome aspirin is normally contraindicated in children
What is one condition where aspirin can be used in children?
Kawasaki disease
Investigation for Kawasaki disease
Clinical diagnosis - no specific test
Echocardiogram is used as the initial screening test for coronary artery aneurysms
What is a complication of Kawasaki disease
Coronary artery aneurysm
Chondromalacia patellae
Softening of the cartilage of the patella
Common in teenage girls
Characteristically anterior knee pain on walking up and down stairs and rising from prolonged sitting
Usually responds to physiotherapy
Osgood-Schlatter disease
tibial apophysitis
Seen in sporty teenagers
Pain, tenderness and swelling over the tibial tubercle
Osteochondritis dissecans
Pain after exercise
Intermittent swelling and locking
Patellar subluxation
Medial knee pain due to lateral subluxation of the patella
Knee may give way
Patellar tendonitis
More common in athletic teenage boys
Chronic anterior knee pain that worsens after running
Tender below the patella on examination
McCune-Albright syndrome
Not inherited, it is due to a random, somatic mutation in the GNAS gene.
Features of McCune-Albright syndrome
- precocious puberty
- cafe-au-lait spots
- polyostotic fibrous dysplasia
- short stature
Measles
> RNA paramyxovirus
spread by droplets
infective from prodrome until 4 days after rash starts
incubation period = 10-14 days
Features of Measles
- prodrome: irritable, conjunctivitis, fever
- Koplik spots (before rash):
- white spots (‘grain of salt’) on buccal mucosa
- rash: starts behind ears then to whole body,
- discrete maculopapular rash becoming blotchy & confluent
What is the prodrome symptoms of measles?
Irritable, conjunctivitis, fever
Koplik spots
Seen in measles - small, white spots that occur on the inside of the cheeks early in the course of measles.
Investigations for Measles
IgM antibodies can be detected within a few days of rash onset
Management of measles
> mainly supportive
admission may be considered in immunosuppressed or pregnant patients
Inform public health
Most common complication of measles
Otitis media
Most common complication causing death in measles
Pneumonia
Meckel’s diverticulum
A congenital diverticulum of the small intestine.
A remnant of the vitellointestinal duct and contains ectopic ileal, gastric or pancreatic mucosa
Features of Meckel’s diverticulum
Abdominal pain mimicking appendicitis
Rectal bleeding
Intestinal obstruction
Most common cause of painless massive GI bleeding requiring a transfusion in children between the ages of 1 and 2 years
Meckel’s diverticulum
Management of Meckel’s diverticulum
Removal if narrow neck or symptomatic
Meconium aspiration syndrome
Refers to respiratory distress in the newborn as a result of meconium in the trachea. It occurs in the immediate neonatal period.
What ages are the 3 doses of the MEN B vaccine given?
2 months
4 months
12-13 months
Contraindication to lumbar puncture
focal neurological signs papilloedema significant bulging of the fontanelle disseminated intravascular coagulation signs of cerebral herniation meningococcal septicaemia
Management of Meningitis in children
< 3 months: IV amoxicillin (or ampicillin) + IV cefotaxime
> 3 months: IV cefotaxime (or ceftriaxone)
Meningitis organisms - Neonatal to 3 months
Group B Streptococcus
E. coli and other Gram -ve organisms
Listeria monocytogenes