The Febrile Child with Unknown Origin Flashcards
What are the possible bacterial causes of pyrexia with unknown origin?
- UTI
- Pneumonia
- Endocarditis
- Occult abscesses
- TB
- Osteomyelitis
What are the possible viral causes of pyrexia with unknown origin?
- Infectious mononucleosis
- Hepatitis
- HIV
What are the other causes of pyrexia with unknown origin?
- Collagen vascular disease
- Inflammatory bowel disease
- Neoplastic disease
- Factitious fever
What would elevated WCC in FBC indicate?
- Bacterial infection
- Very high WCC in leukaemia
In which scenarios would ESR be elevated?
- Bacterial infection
- Highly elevated in collagen vascular disease
- Highly elevated in malignancy
When should blood cultures be taken?
- When bacterial infection is suspected
- Repeated samples in endocarditis, osteomyelitis and occult abscesses
When would a bone marrow aspirate be performed?
- Leukaemia
- Metastatic neoplasms
- Rare infections
When would echocardiography be performed?
In endocarditis, vegitations can be seen on the leaflets of heart valves
When would ultrasonography be performed?
Identification of intra-abdominal abscesses
When would total body CT or MRI scanning be indicated?
In detection of neoplasms or abscesses
What should not be given when a child presents with PUO?
Antipyretics as they obscure the pattern of fever
What should be suspected if the child has recurrent serious infections?
- Defective white cell function
- Immunoglobulin deficiency (congenital, HIV)
- Splenectomy
- Chest (foreign bodies, cystic fibrosis)
- Urinary tract (reflux)
- Meningitis (congenital dermal sinus)
What are the characteristics of tonsillitis?
- Pharyngitis
- Fever
- Malaise
- Lymphadenopathy
What is the most common causative organism of tonsillitis?
Streptococcus pyogenes (over 50% of cases)
What are the complications of tonsillitis?
- Otitis media
- Recurrent tonsillitis
- Quinsy - peritonsillar abscess
- Rheumatic fever and glomerulonephritis (rare, post-strep allergic disorders)
When should surgery be considered in tonsillitis?
If the patient meets the following criteria:
- Sore throats due to tonsillitis
- > 7 episodes per year, 5 per year for 2 years or 3 per year for 3 years
- Symptoms occurring for at least a year
- Episodes of sore throat are disabling and prevent normal functioning
What are the complications of a tonsillectomy?
Primary (<24 hours):
- Haemorrhage (2-3%), commonly due to inadequate haemostasis
- Pain
Secondary (24 hours-10 days):
- Haemorrhage, commonly due to infection
- Pain
What are the criteria for diagnosing tonsillitis?
FeverPAIN:
- Fever (during previous 24 hours)
- Purulence
- Attend rapidly (withthin 3 days of symptoms)
- Inflamed tonsils
- No cough or coryza
Each is worth 1 point, higher score suggests more severe symptoms and likely bacterial cause
Centor criteria:
- Tonsillar exudate
- Tender anterior cervical lymphadenopathy or lymphadenitis
- History of fever
- Absence of cough
What is the difference in presentation between viral and bacterial tonsillitis?
Bacterial:
- More commonly associated with cervical lymphadenopathy
Viral:
- More likely to present with headache, apathy, abdominal pain
What is the management of group A beta-haemolytic strep induced tonsillitis (eg. strep pyogenes)?
- Analgesics (paracetamol: 10-15 mg/kg orally every 4-6 hours)
- Antibiotics once group A strep confirmed by throat swabs (phenoxymethylpenicillin <=27kg give 250mg orally 2-3x PD for 10 days, >27kg 500mg 2-3x PD for 10 days)
- If symptoms are severe consider corticosteroids (dexamethosone sodium phosphate)
When should antibiotics not be considered in acute sinusitis?
Children over the age of 4, unless they are systemically unwell or have complications
When would the FeverPAIN and Centor criteria warrant antibiotic prescription?
FeverPAIN:
- 2-3 consider abx
- >= 3 prescribe abx
Centor:
- >= 3 prescribe abx
When should children with otitis media be offered antibiotics?
- Otorrhea, this indicates tympanic membrane perforation
- <2 years old with bilateral acute otitis media (regardless of temperature)
- Presence of a high temperature >38
How long does acute otitis media tend to last?
4 days
How long does acute sore throat/ pharyngitis/ tonsillitis tend to last?
1 week
How long does acute rhinosinusitis tend to last?
2.5 weeks
How long does acute cough/ bronchitis tend to last?
3 weeks
How does a peritonsillar abscess (quinsy) usually present?
- Severe sore throat that can cause difficulty opening the mouth (trismus)
- Drooling
- Foul-smelling breath
- Deviation of the uvula towards unaffected side (due to throat swelling)
- Otalgia
How does a retropharyngeal abscess present?
- High fever
- Severe sore throat
- Difficulty swallowing
- Nuchal rigidity
What is the management of peritonsillar abscess?
- Definitive treatment is needle aspiration (or incision and drainage)
- Abx (co-amoxliclav or benzylpenicillin and metronidazole), should cover anaerobic and aerobic bacteria
- IV rehydration (if fluid intake is low)
What are the main bacterial causes of otitis media?
- Strep pneumonaie
- Haemophilus influenzae
- Moraxella catarrhalis
Why do viral URTIs typically procede otitis media, while the otitis media infections themselves are bacterial?
Viral URTIs disturb the normal nasopharyngeal microbiome, allowing bacteria to infect the middle ear via the Eustachian tube
What are the features of otitis media?
- Otalgia (rubbing/ tugging of ear)
- Fever (~50%)
- Hearing loss
- Recent viral URTI
- Otorrhea (tympanic membrane perforates)
What are the findings of acute otitis media on otoscopy?
- Bulging tympanic membrane
- Opacification or erythema of the tympanic membrane
- Perforation with purulent otorrhoea
- Decreased mobility if using pneumatic otoscope
How is chronic beingn otitis media characterised?
Dry tympanic membrane perforation without chronic infection
How is chronic seccretory otitis media (glue ear) characterised?
Persistent pain lasting several weeks after the initial episode with reduced motility of the tympanic membrane and an abnormal-looking drum
What is chronic suppurative otitis media?
Persistent prurulent drainage through the perforated tympanic membrane
Defined as perforation of the tympanic membrane with otorrhea >6 weeks
How long do symptoms persist in otitis media?
Usually ~3 days but can last up to a week
What is the management for otitis media?
- Usually self-limiting
- Analgesics for symptomatic relief (paracetamol/ ibuprofen)
- Amoxicillin if indicated (first line oral abx)
What is the dose of oral amoxicillin in otitis media?
- 1-11 months: 125mg x3 PD for 5-7 days
- 1-4 years: 250mg x3 PD for 5-7 days
- 5-17 years: 500mg x3 PD for 5-7 days
What are the alternative oral abx to amoxicillin for otitis media?
- Clarithromycin (alternative first choice if there’s an allergy or intolerance)
- Co-amoxiclav (worsening symptoms on first choice abx for at least 2-3 days)
When should abx be prescribed immediately in otitis media?
- Symptoms lasting >= 4 days/ not improving
- Systemically unwell but not requiring admission
- Immunocompromised/ high risk of complications
- <2 years with bilateral otitis media
- Otitis media with perforation
What are the common sequelae of otitis media?
- Perforation of the tympanic membrane
- Hearing loss
- Labyrinthitis
What are the complications of otitis media?
- Mastoiditis
- Meningitis
- Brain abscess
- Facial nerve paralysis
What are the causative organisms of childhood UTIs?
- E.coli (~80% of cases)
- Proteus
- Pseudomonas
- Klebsiella
- Staphylococcus saprophyticus
How do infants <3 months present with UTI?
- Fever
- Vomiting
- Lethargy
- Irritability
- Poor feeding
- Failure to thrive
- Offensive urine
How do infants aged 3-12 months present with UTI?
- Fever
- Poor feeding
- Abdominal pain
- Vomiting
How do children >1 year old present with UTI?
- Fequency
- Dysuria
- Abdominal pain
Which features would suggest an upper UTI?
- Temperature >38
- Loin pain/ tenderness
At which age are UTI patients always referred?
Babies <3 months with suspected UTI should be referred to paediatric specialist care and:
- Urine sample urgent microscopy and culture
- Appropriate management
What is the method for urine collection in a suspected UTI?
- Clean catch preferable
- If clean catch not possible, urine collection pads
- Invasive methods eg. suprapubic aspiration should only be used when non-invasive methods aren’t possible
Ideally before they’ve taken antibiotics, but treatment shouldn’t be delayed in seriously ill children if a urine sample can’t be obtained
What are the next step if the urine sample can’t be collected during the consultation?
Depending on the severity of infection, advise the parents/ carers to collect and return the urine asap, ideally within 24 hours
If the patient is between 3 months and 3 years with suspected UTI and leukcyte esterase and nitrite are negative on urine dip, what are the next steps?
- Do not give abx
- Do not send a urine sample for microscopy and culture unless indicated
If the patient is between 3 months and 3 years with suspected UTI and at least one of leukcyte esterase and nitrite are positive on urine dip, what are the next steps?
- Send the urine sample for culture
- Give abx
If this child is >3 and Leukocyte esterase and nitrite are both positive on urine dip?
Assume the child has a urinary tract infection (UTI) and give them antibiotics. If the child has a high or intermediate risk of serious illness or a history of previous UTI, send a urine sample for culture.
If this child is >3 and Leukocyte esterase is negative and nitrite is positive on urine dip?
Give the child antibiotics if the urine test was carried out on a fresh urine sample. Send a urine sample for culture. Subsequent management will depend on the result of urine culture.
If this child is >3 and Leukocyte esterase is positive and nitrite is negative on urine dip?
Send a urine sample for microscopy and culture. Do not give the child antibiotics unless there is good clinical evidence of a UTI (for example, obvious urinary symptoms). A positive leukocyte esterase result may indicate an infection outside the urinary tract that may need to be managed differently.
If this child is >3 and Leukocyte esterase and nitrite are both negative on urine dip?
Assume the child does not have a UTI. Do not give the child antibiotics for a UTI or send a urine sample for culture. Explore other possible causes of the child’s illness.
What are the indications for sending urine for microscopy and culture in a baby or child?
- Suspicion of an upper UTI
- High or intermediate risk of serious illness
- Under 3 months old
- Positive result for leukocyte esterase or nitrite
- Recurrent UTI
- Infection that doesn’t respond to treatment in 24 or 48 hours, if no sample has been sent
- Clinical symptoms and signs but dipstick tests don’t correlate
What is pyuria?
High white blood cells or pus in the urine
What does a microscopy result of pyuria and bacteriuria are both positive indicate?
Assume the baby or child has a urinary tract infection (UTI)
What does a microscopy result of pyuria is positive and bacteriuria is negative indicate?
Start antibiotic treatment if the baby or child has symptoms or signs of a UTI
What does a microscopy result of pyuria is negative and bacteriuria is positive indicate?
Assume the baby or child has a UTI
What does a microscopy result of pyuria and bacteriuria are both negative indicate?
Assume the baby or child does not have a UTI
How are upper and lower UTIs clinically differentiated?
Upper UTI:
- Bacteriuria and fever of >=38
- Bacteriuria, fever <38 and loin pain or tenderness
Lower UTI:
- Bacteriuria but no systemic symptoms or signs of lower UTI (cystitis)
How are antibiotics delivered to babies <3 months with suspected UTI?
Parenteral antibiotics
What’s the first choice oral antibiotic for pyelonephritis in children >3 months?
Cefalexin
(Co-amoxiclav if the culture results are available and it’s susceptible)
Both given 7-10 days
What are the first choice antibiotics for children and young people with a lower UTI?
Trimethoprim or nitrofurantoin orally for 3 days
(nitrofurantoin is more expensive, so if both are available the cheapest option should be chosen)
What are the second choice antibiotics for lower UTI in children and young people?
Nitrofurantoin (if not used as first choice), amoxicillin or cefalexin
Should be taken if symptoms get worse on a first-choice antibiotic taken for at least 48 hours, or if first choice abx aren’t suitable
What are the main side effects of the UTI abx?
Diarrhoea and nausea
What is the threshold for asymptomatic bacteriuria?
> 10^5 colony forming units/ml in the urine with no symptoms of UTI
What are the features of an atypical UTI?
- Seriously ill
- Poor urine flow
- Abdominal or bladder mass
- Raised creatinine
- Septicaemia
- Failure to respond to treatment with suitable abx within 48 hours
- Infection with non-E.coli organisms
What is the definition of a recurrent UTI?
- x2 or more episodes of UTI with acute upper UTI
- x1 episode of UTI with acute upper UTI + 1 or more episodes of UTI with lower UTI
- x3 or more episodes of UTI with lower UTI
When should babies and children with a lower UTI be sent for ultrasound?
Within 6 weeks:
- Younger than 6 months
- Have had recurrent infections
What is the function of a DMSA scan?
To detect renal parenchymal defects
What is a micturating cystourethrogram (MCGU)?
Contrast is injected into the bladder via a catheter and an x-ray is used to visualise the flow of urine from the kidneys to the urethra
When would MCGU be considered?
Only in babies <6 months, not really indicated in older children
- If the ultrasound at 6 weeks is abnormal
- If there’s an atypical UTI
- If there are recurrent UTIs
When would a DMSA scan (4-6 months after acute infection) be considered?
- Atypical UTI
- Recurrent UTIs
Which clinical features would indicate an MCUG?
- Dilatation on ultrasound
- Poor urine flow
- Non-E.coli infection
- Family hx of VUR
What are some complications of UTI?
- Renal scarring and CKD
- Sepsis
What is vesicoureteral reflux?
Urine flows backwards from the bladder into the ureters and kidneys
What is the pathophysiology of VUR?
- Shortened intravesical ureter
- Improperly functioning valve
- Neurological disorder affecting the bladder
What is the conservative management of VUR?
- Prophylactic abx to prevent regular UTIs
- Regular monitoring of kidney function and growth
- Treatment of constipation if present
What is the surgical management of VUR?
- Ureteral reimplantation
What are the complications of VUR?
- Recurrent UTIs
- Pyelonephritis
- Renal scarring and CKD
- Hypertension
What can nitrofurantoin trigger?
G6PD mediated haemolysis
What is the inheritance pattern of cystic fibrosis?
Autosomal recessive
What is the pathophysiology of cystic fibrosis?
A defect in the cystic fibrosis transmembrane conductance regulator gene (CFTR), which codes a cAMP-regulated chloride channel, leading to increased viscosity of secretions
What is the genetic defect in ~80% of cystic fibrosis cases?
Delta F508 on the q arm of chromosome 7 resulting in abnormal glycosylation and degredation of CFTR protein before it reaches the cell membrane
Which organisms may colonise CF patients?
- Staph aureus
- Pseudomonas aeruginosa
- Burkholderia cepacia
- Aspergillus
What is the presentation of CF in neonates?
- Meconium ileus, viscous meconium causes a delay in passing meconium and possibly GI obstruction
- Prolonged jaundice, less common
What is the diagnosis and management of meconium ileus in neonates?
Gastrograffin enema
How does CF tend to present in infants?
- Salty sweat
- Faltering growth
- Recurrent chest infections (~40%)
How does CF tend to present in toddlers?
- Faltering growth
- Recurrent chest infections (~40%)
- Malabsorption syndromes (~30%) (steatorrhea, failure to thrive)
How does CF tend to present in older children?
- Faltering growth
- Recurrent chest infections (~40%)
- Malabsorption syndromes (~30%) (steatorrhea, failure to thrive)
- Delayed onset of puberty
- Other features including liver disease (~10%)
What % of patients are diagnosed with CF after the age of 18?
5%
What are the less common features of CF?
- Short stature
- Diabetes mellitus
- Delayed puberty
- Rectal prolapse (bulky stools)
- Nasal polyps
- Male infertility, female subfertility
When is CF first screened for?
Neonatal blood spot test on day 5 of life, raised blood immunoreactive trypsinogen indicates CF
Why does CF increase blood immunoreactive trypsinogen?
Mucus plugs can block the pancreatic ducts, preventing trypsinogen from reaching the small intestine
What is the definitive test for CF?
Sweat test:
- >60mEq/l (normal <40mEq/l Cl- in the sweat as chloride can’t be reabsorbed from the sweat)
Gene testing (less commonly done in children)
What are the causes of a false positive sweat test in suspected CF?
- Malnutrition
- Adrenal insufficiency
- Glycogen storage diseases
- Nephrogenic diabetes insipidus
- Hypothyroidism, hypoparathyroidism
- G6PD
- Ectodermal dysplasia
What is the most common cause of a false negative sweat test?
Skin oedema
- Often due to hypoalbuminaemia/ hypoproteinaemia secondary to pancreatic exocrine insufficiency
What is the management of CF?
- Regular (at least x2 per day) chest physio and postural drainage
- High calorie diet, including high fat intake (requires more energy to breathe normally, fight infections etc)
- Minimise contact with other CF patients to prevent cross infection with opportunistic bacteria
- Vitamin supplementation (ADEK)
- Pancreatic enzyme supplements taken with meals (eg. Creon)
- Regular immunisation with flu and pneumococcal vaccines
- Prophylactic abx, bronchodilators, and medicines to thin secretions
- Lung transplantation (end stage pulmonary disease)
What is a contraindication for lung transplantation in CF patients?
Chronic infection with Burkholderia cepacia
What is Lumacaftor/Ivacaftor dual therapy used for?
Treatment for CF patients who are homozygous for the delta F508 mutation
What is the function of Lumacaftor?
Increases the number of CFTR proteins that are transported to the cell surface
What is the function of Ivacaftor?
Potentiator of CFTR that is already at the cell surface, increasing the probability that the defective channel will be open and allow chloride ions to pass through the channel pore
What is characteristic of meconium ileus on x-ray?
Bubbly appearance of the intestine and lack of air-fluid levels
How is the sweat test conducted in CF?
- Pilocarpine is applied to the chosen patch of skin on the arm
- Current is passed between the electrodes placed on either side of the patch, causing the skin to sweat
- Sweat is absorbed by filter paper and analysed for chloride concentration
