Paediatric Infectious Diseases Flashcards
What is sepsis?
SIRS and suspected or proven infection
Severe sepsis - sepsis plus organ dysfunction
Septic shock - sepsis and CVS dysfunction
Describe systemic inflammatory response syndrome
SIRS
2 or more of - temp > 38 degrees/ <36, WCC >15x10^9 or <5, tachycardia >2SD and tachypnoea >2SD for normal age
What is used for plotting paediatric values?
PEWS charts
What are signs for red flags in sepsis?
Sleeping more, needing stimulation for waking, not doing as much activity, if they are just lying there, can’t wake up and high pitched cry
Evidence of difficulty with breathing
Capillary refill time (over sternum) and how the child looks
Rigors (bacterial infection), non-blanching rashes and bulging fontanelles
What is the SEPSIS 6 for paediatric diagnosing sepsis?
Temperature, inappropriate tachycardia, proper peripheral perfusion, neuro changes (altered mental state), tachypnoeic and hypotension
What are the children to think about when diagnosing sepsis?
Under 3 months, immunosuppressed, chemotherapy, on long-term steroids, recent surgery, neuro disabilities and lines/ catheters
Why do we worry about infants under 3 months?
Increased risk of bacterial infection, sepsis and meningitis
Minimal signs and symptoms
May not mount to a febrile response - 50%
Can deteriorate quickly
What are some risk factors for infants under 3 months for sepsis?
Prematurity, PROM, maternal pyrexia/ chorioamnionitis, maternal GBS (this and previous pregnancy) and maternal STIs
What is the management for sepsis in children?
Give high flow O2
ABC
Fluid bolus based on weight
DEFG - 2ml/kg 10% dextrose if hypoglycaemia
Antibiotics - 3rd generation cephalosporin (cefotaxime/ ceftriaxone) and add IV amoxicillin if under 1 month
What investigations are done if suspected sepsis?
Bloods - FBC, CRP, coagulation screen, blood gas, glucose and blood culture
Cultures - blood, urine and CSF (possible stool)
Imaging - CXR
What are the responsible organisms in sepsis for neonates?
Group B streptococcus, E. coli and Listeria monocytogenes
What are the responsible organisms for sepsis in older infants and children?
Streptococcus pneumoniae, Neisseria meningitidis, group A streptococcus and staphylococcus aureus
What is the definition of meningitis?
A disease caused by inflammation of the meninges
Meningism is the clinical signs and symptoms suggestive of meningeal infection
What are the signs and symptoms of meningitis in older children?
Fever, headache, photophobia, neck stiffness, N/V, reduced GCS, seizures and focal neurological signs
What are the signs and symptoms seen in young infants for meningitis?
Fever or hypothermia, poor feeding, vomiting, vomiting, lethargy, irritability, respiratory distress and apnoea
What are some clinical signs of meningitis?
Nuchal rigidity (neck stiffness) - palpable resistance to neck flexion
Brudzinski’s sign - hips and knees flex on passive flexion of the neck
Kernig’s sign - pain on passive extension of the knee
What are the causes of childhood meningitis?
Bacteria
Mainly viral - enterovirus
Fungal - neonates and immunocompromised
Unknown and aseptic
What are the responsible organisms for bacterial meningitis in noenates?
Group B streptococcus, E. coli and Listeria monocytogenes
What are the responsible organisms for older infants and children for meningitis?
Streptococcus pneumoniae, Neisseria meningitidis and haemophilus influenza type B
Describe haemophilus influenza
Small, non-motile, gram-negative coccobacillus
Nasopharyngeal carriage
Encapsulated H. influenza - resists phagocytosis and complement mediated lysis
Hib main cause of invasive H. influenza
Describe Neisseria meningitidis
Gram negative diplococcus
Humans only natural hosts
Nasopharyngeal carriage
Infection follows viral URTI
Polysaccharide capsule - determines serogroup
Endotoxin (LPS)
What are the risk factors for invasive meningococcal disease?
Age under 1 year and 15-24 years
Unimmunised, crowded living conditions, household/ kissing contact, cigarette smoking, recent viral/ Mycoplasma infection and complement deficiency
What can be seen in invasive meningococcal disease?
25% septicaemia
15% meningitis
60% petechiae/ purpura rash
Describe invasive meningococcal disease
Rapidly progressive
Case fatality rate is 5-15%
Significant long term sequelae - amputation, scarring, hearing loss and cognitive impairment/ epilepsy
Describe streptococcus pneumoniae (pneumococcus)
Gram positive, lancet-shaped diplococcus
Facultative anaerobe
Polysaccharide capsule
More than 90 known serotypes and all can cause invasive disease
Colonised nasopharynx
Proceeding URTI and resp droplet transmission
What are the risk factors for invasive pneumococcal disease?
Age under 2 years, cigarette smoking, recent viral URTI, attendance at childcare, cochlear implant, sickle cell disease, asplenia, HIV infection, nephrotic syndrome and immunodeficiency
Describe pneumococcal meningitis
Case fatality of 8% in children
Neurological sequelae common - hydrocephalus, neuro-disability, seizures, hearing loss and blindness
What is the basic management of meningitis?
ABC
20ml/kg fluid bolus
2ml/kg 10% dextrose
Antibiotics - 3rd generation cephalosporin (cefotaxime/ ceftriaxone)
Add amoxicillin if under 1 month
What are the investigations for meningitis?
Bloods - FBC, U+Es, LFTs, CRP, coagulation screen, blood gas, glucose, blood culture and PCR
Lumbar puncture - essential and ideally before antibiotics but don’t delay
What should be requested for lumbar puncture and seen on LP for meningitis?
Request - microscopy, gram stain, culture, protein, glucose and viral PCR
Findings - turbid/ purulent, high opening pressure, increased WCC, protein and decreased glucose
What are the contraindications for doing a lumbar puncture?
Signs of raised ICP - GCS under 9, abnormal tone/ posture, pupillary defects, bradycardia + HTN, papilledema
Focal neurological signs, recent seizures, CV unstable, coagulopathy, thrombocytopenia and extensive purpura
Describe the microbiology of staphylococcus aureus
Gram positive cocci, coagulase positive, produce exotoxins and form super-antigens, colonises skin + mucosa and resistance is a problem
Describe the microbiology of streptococcus pyogenes
Gram positive cocci, B-haemolytic, produce exotoxins and forms super-antigens, oropharyngeal carriage and resistance is not a problem
What are some skin and soft tissue infections caused by staph and strep infections?
Cellulitis, boils/ furuncles, impetigo, infected eczema and lymphadenitis
Describe staphylococcal scalded skin syndrome
Usually under 5 years
Toxin mediated
Initial bullous lesions followed by widespread desquamation
Nikolsky sign, purulent conjunctivitis and mild fever
What is the treatment for staphylococcal scalded skin syndrome?
IV flucloxacillin and IV fluids
Describe the pattern of infection of scarlet fever
Group A strept infection
2-5 day incubation period
Fever, malaise and sore throat with strawberry tongue
Sandpaper rash
Then skin peeling
Lasts 7 days
What is the management of scarlet fever?
Notifiable disease
Phenoxymethylpenicillin (penicillin V) for 10 days
Reduces transmissions and incidence of complications
What are some of the complications of scarlet fever?
Abscess formation - retropharyngeal or peritonsillar
Acute rheumatic fever - arthritis, carditis, chorea, erythema marginatum and subcutaneous nodules
Post-streptococcal glomerulonephritis
What is toxic shock syndrome?
Acute febrile illness caused by gram positive bacteria which rapidly progresses to shock and multiorgan failure
Super-antigen causes intense T cell stimulation - excessive immune activation and pro-inflammatory cytokine release
High case fatality
What are the clinical features of toxic shock syndrome?
Fever, diffuse maculopapular sunburn rash, mucosal changes (swollen lips, strawberry tongue + non-purulent conjunctivitis), profuse diarrhoea in S. aureus and rapid progression to shock + multiorgan failure
What is the management of TSS?
ABC
Fluid restriction and inotropes
Cultures
IV antibiotics - flucloxacillin and clindamycin
IVIG
Avoid NSAIDs
Surgical debridement
