Infectious diseases in paediatrics Flashcards
1
Q
Learning outcomes
A
- Understand the presentation, diagnosis and management of bacterial meningitis and septicaemia.
- Recognise common patterns of streptococcal and staphylococcal infection and their treatments.
- Recognise herpes simplex, varicella zoster and enterovirus infection and their treatments.
- Recognise the presentation of Kawasaki Disease.
- Be aware of the presenting features of an underlying immunodeficiency including HIV and the initial approach to assessing these children.
2
Q
Sepsis in children
A
- Leading cause of death in children
- ½ of all sepsis worldwide occur in children
- Earlier recognition and treatment → better survival
3
Q
Definitions of sepsis
A
- Sepsis = systemic inflammatory response syndrome + suspected/ proven infection
- Severe sepsis = sepsis and organ dysfunction
- Septic shock = sepsis and CVS dysfunction
4
Q
Criteria for Systemic Inflammatory Response Syndrome (SIRS)
A
- Temperature → >38c or > 36 C
- Leucocytosis or leucopenia
- Tachycardia
- Tachypnoea
5
Q
Infants <3 months of age
A
- Increased risk of bacterial infection
- Increased risk of sepsis
- Increased risk of meningitis
- may show minimal signs and symptoms
- Often presents with non-specific signs and symptoms
- May not present with a febrile response (50%)
- Deteriorate very quickly
6
Q
Risk factors in infants <3 months
A
- Premature (<37/40)
- Premature rupture of membranes
- Maternal pyrexia/ chrorioamnionitis
- Maternal Guillain-barre syndrome
- Previous child with Guillain-barre syndrome
7
Q
Management of sepsis in children
A
- Airways
- Breathing
- Circulation → fluid bolus (20ml/kg 0.9% NaCl)
- DEFG → don’t every forget glucose
- Antibiotics
- 3rd generation cephalosporin
- Add IV amoxicillin if <1 m old
8
Q
Investigations
A
- Bloods
- FBC (leucocytosis, thrombocytopenia)
- CRP
- Coagulation screen (DIC)
- Blood gas (metabolic acidosis, raised lactate)
- Glucose
- Blood culture → give antibiotics anyway
- Culture
- Blood
- Urine
- CSF → including virology
- +/- stool (micro and virology
- Imaging → Chest x-ray
*
9
Q
Responsible organisms
A
- Neonates
- Group B streptococcus
- Escherichia coli
- Listeria monocytogenes
- Older infants and children
- Streptococcus pneumonia
- Neisseria meningitides
- Group A streptococcus
- Stapylococcus aurea
10
Q
Definition of meningitis
A
- Disease causing inflammation of the meninges
11
Q
Definition of meningism
A
- Clinical presentation indicating an inflammation of the meninges
12
Q
Presentation of meningitis in
A
- Older children
- Fever
- Headache
- Photophobia
- Neck stiff neck (nuchal rigidity)
- Nausea/ vomiting
- Reduced GCS
- Seizures
- Focal neurological deficits
- Young infants → non-specific
- Fever/ hypothermia
- Poor feeding
- Vomiting
- Lethargy
- Irritability
- Respiratory distress
- Apnoea
- Bulging fontanelle (raised ICP)
13
Q
Examination of meningitis
A
- Nuchal rigidity
- Neck stiffness
- Palpable resistance to neck flexion
- Brudzinki’s sign → Hips and knees flex on passive flexion of the neck
- Kernig’s sign → Pain on passive extension of knee
14
Q
Aetiology of childhood meningitis (post-vaccination era)
A
- Viral → mainly enterovirus
- Bacterial (4-18%)
- Fungal → neonates and immunocompromised
- Unknown/ aseptic (40-76%)
15
Q
Bacterial causes of meningitis
A
- Neonates (less than 1 month)
- Group B streptococcus
- E.coli
- Listeria monocytogenes
- Older infants and children
- Strep. pneumniae
- Neisseria meningitides
- Haemophilus influenza
16
Q
Neisseria meningitides
A
- Gram negative diplococcus
- Only affects humans
- Nasopharyngeal carriage
- Transmission via respiratory secretions
- Infection following viral URTI
- Polysaccharide capsule
- Endotoxin on LPS
17
Q
Riks factors for invasive meningococcal disease
A
- Less than 1 years or 15-24
- Unimmunised
- Crowded living conditions
- Household or kissing contacts
- Cigarette smoking
- Recent viral/ mycoplasma infection
- Complement deficiency
18
Q
Presentation of meningitis vs septicaemia
A
- Meningitis (15%)
- Neck stiffness
- Bulging fontanelle
- Seizures
- Both (65%)
- Fever
- Headache
- Vomiting
- Reduced GCS
- Petechial/ purpuric rash → non-blanching
- Septicaemia (25%)
- Myalgia
- Abdominal pain
- Limb pain
- Signs of shock
19
Q
Complications of invasive meningococcal disease
A
- Amputation
- Scarring
- Hearing loss
- Cognitive impairment/ epilepsy
20
Q
Streptococcus pneumonia
A
- Gram positive
- Facultative anaerobe
- Polysaccharide capsule
- Inhibits neutrophil phagocytosis
- Inhibits complement mediated cell lysis
- All serotypes cause invasive illness
- Colonises nasopharynx
- Precedes URTI
- Respiratory triplet transmission
21
Q
Diseases caused by pneumococcal infection
A
- Pneumonia
- Pleural and pericardial empyema
- Otitis media
- Sinusitis
- Septicaemia
- Peritonitis
- Arthritis/ osteomyelitis
- Meningitis
22
Q
Risk factors for pneumococcal disease
A
- Age <2 years
- Cigarette smoking
- Recent URTI
- Attendance to childcare
- Cochlear implant
- Sickle cell disease
- Asplenia
- HIV infection
- Nephrotic syndrome
- Immunodeficiency/ immunosuppression
23
Q
Complications of pneumococcal meningitis
A
- Hydrocephalus
- Neurodisability
- Seizures
- Hearing loss
- Blindness
24
Q
Management of meningitis
A
- Airways
- Breathing
- DEFG → don’t forget glucose
- Antibiotics
- 3rd generation cephalosporin
- Add amoxicillin
25
Investigations for meningitis
* Bloods
* FBC (leukocytosis, thrombocytopenia
* U and E, LFT
* CRP
* Coagulation screening
* Blood gas → raised lactate
* Glucose
* **Blood culture**
* Meningococcal/ pneumococcal PCR
* **Lumbar puncture**
* Microscopy
* Gram stain
* Culture
* Protein
* Glucose
* **Viral PCR**
26
Contraindications for lumbar puncture
* Signs of raised ICP
* GCS less 9
* Abnormal tone and posture
* HTN or bradycardia
* Pupillary defect
* Papillodema
* Focal neurological deficits
* Within 30 minutes of seizure s
* Haemodynamically unstable
* Coagulopathy
* Thrombocytopenia
* Extensive/ extending purport
27
CSF findings in bacterial meningitis
* Turbid or purulent
* High opening pressure
* Increased WCC (polymorphs)
* Increased protein
* Decreased glucose
28
Treatment duration for meningitis
* Varies depending on the causative organism
* Longest duration → listeria monocytogenes
29
Summary of meningitis
* Bacterial meningitis has serious long-term consequences
* Meningitis and sepsis can progress rapidly
* Early treatment is essential
* Vaccination can provide effective protect against childhood causes of meningitis
30
Staph and strep infection
* Human pathogen with risk of invasive infection
* Majority cause skin and soft tissue infection
* Clinically relevant serotypes → Staph. aureas and strep. pyogenes
* Both cause osteoarticular infection
* Both cause bacteraemia
* Both cause toxin-mediated disease → toxic shock syndromes
* Difficult to distinguish clinically
31
Strep vs staph
* Staph
* Coagulae +ve
* Colonises skin and mucosa
* Resistance → MRSA
* Both
* Gram positive cocci
* Produces exotoxin and form superantigans
* Strep
* Beta-haemolytic
* Colonises oropharynx
* Resistance → not a problem
32
Skin and soft tissue infections caused by staph and strep
* Cellulitis
* Boils and furuncles
* Impetigo
* Infected eczema
* Lymphadenitis
33
Staphylococcal scalded skin syndrome
* Usually \<5 years
* Toxin-mediated (exfoliatoxin)
* Initial bullies lesions
* Widespread desquamation
* Nikolsky's sign
* Mild fever
* Purulent conjunctivitis
* Management
* IV flucloxacillin
* IV fluids
34
Nikolsky sign
* Desquamation of top layer of skin on minimal rubbing
35
Scarlet fever
* Caused by Group A strep
* 2-5 days incubation
* Fever, malaise, sore throat
* Strawberry tongue
* Sandpaper rash
* Skin peeling
36
Scarlet fever management
* Notify public health
* Penicillin (phenoxymethylpenicillin 10 days
37
Function of phenoxymethylpenicillin in scarlet fever
* Reduces duration and severity fo disease
* Reduces complications
* Quincy/ acute rheumatic fever
* Post-streptococcal glomerulonephritis
* Reduces transmission
38
Complications of scarlet fever
* Abscess formation → retropharyngeal and peritonsillar (Quincy)
* Acute rheumatic fever
* Commonest cause of acquired heart disease
* Arthritis, carditis, chorea, erythema marginatum, subcutaneous nodules
* Post-streptococcal glomerulonephritis
39
Definition of toxin shock syndrome (TSS)
* Caused by both streptococcus or streptococcus organisms
* Acute febrile illness
* Rapidly progressing shock and multi organ failure
* Cause
* Superantigen → intense T cell activation
* Excessive immune activation
* Cytokine storm
* Highly fatal
40
Clinical features of TSS
* Fever
* Diffuse maculopapular rash
* Mucosal changes
* Swollen lips
* Non-purulent conjunctivitis
* Strawberry tongue
* Profuse diarrhoea (s.aurea)
* Shock and multi-organ failure
* Tachycardia
* Prolonged cap refill
* Hypotension
* Renal impairment
* Transaminitis → high levels of transaminase
* Reduced GCS
41
Management of toxic shock syndrome
* ABC
* Fluid resuscitation +/- inotropes
* Cultures
* Blood
* Throat swab
* Wound
* IV antibiotics → flucloxacillin and clindamycin
41
Management of toxic shock syndrome
* ABC
* Fluid resuscitation +/- inotropes
* Cultures
* Blood
* Throat swab
* Wound
* IV antibiotics → flucloxacillin and clindamycin
* Avoid NSAID's
* Surgical debridement
