Infection/Immunity Flashcards
What is the most common cause of meningitis?
Viral
What is the most common bacterial cause of meningitis in neonates?
GBS
E.coli
Listeria
What is the most common bacterial cause of meningitis in children and adolescents?
N.meningitides
S.pneumoniae
What process causes the damage in meningitis?
Inflammation leads to endothelial damage = cerebral oedema (raised ICP) = cortical infarction
most of the damage is caused by the host’s immune response
What might bulging fontanelle in a neonate suggest?
Raised ICP
What are the long term complications of meningitis?
Hearing loss
Subdural effusion
Abscesses
Infarction
What ix should be ordered in suspected meningitis?
FBC BM Gas LP (PCR) Rapid Ag test MCS (blood, stool, urine, throat)
What is the management for bacterial meningitis?
IV benpen until at hospital
Then 3rd gen cephalosporin (e.g. ceftriaxome/cefotaxime)
Dexamethasone
Supportive therapy
Prophylactic against MenC for other family members
What are the cardinal symptoms of encephalitis?
Altered behaviour
Reduced consciousness
Fever
Seizures
What is the most common causative agent for encephalitis?
HSV
What are the appropriate ix for suspected HSV?
FBC LP EEG - changes in temporal lobe CT/MRI - focal changes in temporal lobe (meningitis screen)
How is HSV diagnoses?
PCR from CSF
How is HSV encephalitis treated?
3/52 IV aciclovir
Supportive care
What is the commonest cause of UTI in a child?
Bowel flora migrates to UT
What is the commonest cause of UTI in a neonate?
Haematogenous spread
Which organisms commonly cause UTI? Which organisms are more common in boys?
E.coli,
Klebsiella,
Proteus (more common in boys because populates under prepuce)
What are the risk factors for UTIs?
Incomplete emptying Infrequent voiding Vulvitis Constipation Neuropathic bladder Vesicoureteric reflux (familial) Posterior urethric valves (in boys)
What is vesicoureteric reflux?
Reflux of urine back up ureters. Can be mild (a little way up) or moderate (tracking back to kidneys). Risk factor for UTIs
What may a pseudomonas caused UTI indicate?
Structural abnormalities - blockage
How should a suspected UTI be investigated?
Urine dip (+MC&S) FBC, U&E, CRP
When should UTIs be investigated further beyond bloods and urine?
If atypical organisms (non-E.coli) OR recurrent UTIS
–> for USS
What might be found on USS of a child with recurrent UTIs?
Strictures
Posterior urethral valve
Dilated ureter/calyces indicating vesicuourethral reflux
What is the treatment for <3mo baby with a UTI?
Hospital admission - IV cefotaxime
What is the treatment for a 6week - 2yrs child with a UTI?
Coamox
IV cef if unstable
What is the treatment for recurrent UTI?
Trimethoprim (3/7)
What is the conservative management/advice for a child with UTI?
Increased fluid intake
Second attempt at emptying to ensure complete void
What are the long term complications of UTIs?
Kidney scarring leading to HTN and CKD
What is the incubation period of chickenpox?
11-21 days
How long are children with chickenpox infective for?
4 days before lesions to until all lesions are scabbed over
What is the treatment for chickenpox?
Keep cool
Antiseptic cream for lesions
Trim nails
IV aciclovir if severe
VZIG if immunocompromised and exposed (no prior infection)
What is the evolution of chickenpox lesions?
Macules, papules, vesicles
How does lyme disease present?
Eythema migricans Fever Malaise Mylagia Lymphadenopathy
(can be neuro and cardio involvement)
What is the treatment for >12 years with lyme disease?
Doxy
What is the treatment for <12 years with lyme disease?
Amoxicillin
What is the treatment for lyme disease with neuro/cardiac involvement?
IV ceftriaxone
What is Kawasaki’s disease?
Immune hyperreactivity causing systemic vasculitis
How does Kawasaki’s disease present?
Very irritable Prolonged fever >5 days (difficult to control) Non-purulent conjunctivitis Red mucous membranes Peeling hands and feet Lymphadenopathy (Inflammation at BCG site)
What are the long term complications of Kawasaki’s disease?
Coronary artery aneurysms
What are the investigations for Kawasaki’s disease?
FBC (raised WCC, ESR, CRP)
Echo (after 6/52 to check for cardiac aneurysms)
What is the treatment for Kawasaki’s disease?
IVIG Steroids Ciclosporin Infliximab Aspirin (lower risk thrombosis) Long term warfarin if severe coronary involvement
In which populations is Kawasaki’s disease most common?
Japanese
Afro-Caribbean
Which gene is Kawasaki’s disease associated with?
ITPKC
What are the four species of malaria?
Falciparum
Ovale
Vivax
Malariae
What are the most significant complications of malaria, particularly in children?
Anaemia
Cerebral oedema
What are the investigations for suspected malaria?
FBC
Urinalysis + MC&S
Thick and thin blood film
When do the symptoms of malaria become apparent?
7-10 days after innoculation
How does malaria present?
Swinging fevers (48-72 hours) - although not always Malaise Myalgia Headaches N&V&D Jaundice
What is the treatment for malaria?
PREVENTION
Falciparum - quinine
Others - chloroquine
How is typhoid transmitted?
FO
Salmonella typhi, paratyphi
How does typhoid present?
Worsening fever Frontal headaches, cough, abdo pain, Splenomegaly Bradycardia ROSE COLOURED SPOTS on trunk
How is typhoid diagnosed?
Blood cultures
What is the treatment for typhoid?
Cotrimoxazole
How is dengue transmitted?
Aedes anopheles mosquito
What are the severe symptoms of dengue?
Leukopenia
Thrombocytopenia
Haemorrhage
–> severe capillary leak syndrome
How does dengue fever present?
Fine, erythematous rash, headaches, myalgia
How is dengue diagnosed?
Viral antigen serology
How is dengue treated?
Fluid resus
Monitoring
How is acute otitis media diagnosed?
Assessment of the tympanic membranes
What is the major complicationsof recurrent acute otitis media?
Otitis media with effusion (glue ear) = speech and learning difficulties from (conductive) hearing loss
Otitis media can also track and cause a cerebral abscess
What is the most common age group suffering from acute otitis media?
6-12 months
Why are babies and infants most at risk of acute otitis media?
Short, horizontal, poorly functioning eustachian tubes
What is acute otitis media often associated with?
Viral URTI - bacterial infection grows in viral fluid in ear
What is the most common cause of conductive hearing loss in children?
Otitis media with effusion (glue ear)
Why are neonates less likely to suffer from viral infection (and more likely bacterial)?
Passive immunity from mother
What is the CENTOR criteria for bacterial tonsillitis?
Cough absent Exudate Nodes Temperature Young OR old
What is the commonest causative organism of tonsillitis?
Group A beta haemolytic strep
What percentage of tonsillitis is bacterial?
1/3