Infection/Immunity Flashcards
(168 cards)
1
Q
What is the most common cause of meningitis?
A
Viral
2
Q
What is the most common bacterial cause of meningitis in neonates?
A
GBS
E.coli
Listeria
3
Q
What is the most common bacterial cause of meningitis in children and adolescents?
A
N.meningitides
S.pneumoniae
4
Q
What process causes the damage in meningitis?
A
Inflammation leads to endothelial damage = cerebral oedema (raised ICP) = cortical infarction
most of the damage is caused by the host’s immune response
5
Q
What might bulging fontanelle in a neonate suggest?
A
Raised ICP
6
Q
What are the long term complications of meningitis?
A
Hearing loss
Subdural effusion
Abscesses
Infarction
7
Q
What ix should be ordered in suspected meningitis?
A
FBC BM Gas LP (PCR) Rapid Ag test MCS (blood, stool, urine, throat)
8
Q
What is the management for bacterial meningitis?
A
IV benpen until at hospital
Then 3rd gen cephalosporin (e.g. ceftriaxome/cefotaxime)
Dexamethasone
Supportive therapy
Prophylactic against MenC for other family members
9
Q
What are the cardinal symptoms of encephalitis?
A
Altered behaviour
Reduced consciousness
Fever
Seizures
10
Q
What is the most common causative agent for encephalitis?
A
HSV
11
Q
What are the appropriate ix for suspected HSV?
A
FBC LP EEG - changes in temporal lobe CT/MRI - focal changes in temporal lobe (meningitis screen)
12
Q
How is HSV diagnoses?
A
PCR from CSF
13
Q
How is HSV encephalitis treated?
A
3/52 IV aciclovir
Supportive care
14
Q
What is the commonest cause of UTI in a child?
A
Bowel flora migrates to UT
15
Q
What is the commonest cause of UTI in a neonate?
A
Haematogenous spread
16
Q
Which organisms commonly cause UTI? Which organisms are more common in boys?
A
E.coli,
Klebsiella,
Proteus (more common in boys because populates under prepuce)
17
Q
What are the risk factors for UTIs?
A
Incomplete emptying Infrequent voiding Vulvitis Constipation Neuropathic bladder Vesicoureteric reflux (familial) Posterior urethric valves (in boys)
18
Q
What is vesicoureteric reflux?
A
Reflux of urine back up ureters. Can be mild (a little way up) or moderate (tracking back to kidneys). Risk factor for UTIs
19
Q
What may a pseudomonas caused UTI indicate?
A
Structural abnormalities - blockage
20
Q
How should a suspected UTI be investigated?
A
Urine dip (+MC&S) FBC, U&E, CRP
21
Q
When should UTIs be investigated further beyond bloods and urine?
A
If atypical organisms (non-E.coli) OR recurrent UTIS
–> for USS
22
Q
What might be found on USS of a child with recurrent UTIs?
A
Strictures
Posterior urethral valve
Dilated ureter/calyces indicating vesicuourethral reflux
23
Q
What is the treatment for <3mo baby with a UTI?
A
Hospital admission - IV cefotaxime
24
Q
What is the treatment for a 6week - 2yrs child with a UTI?
A
Coamox
IV cef if unstable
25
What is the treatment for recurrent UTI?
Trimethoprim (3/7)
26
What is the conservative management/advice for a child with UTI?
Increased fluid intake
| Second attempt at emptying to ensure complete void
27
What are the long term complications of UTIs?
Kidney scarring leading to HTN and CKD
28
What is the incubation period of chickenpox?
11-21 days
29
How long are children with chickenpox infective for?
4 days before lesions to until all lesions are scabbed over
30
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)
31
What is the evolution of chickenpox lesions?
Macules, papules, vesicles
32
How does lyme disease present?
```
Eythema migricans
Fever
Malaise
Mylagia
Lymphadenopathy
```
(can be neuro and cardio involvement)
33
What is the treatment for >12 years with lyme disease?
Doxy
34
What is the treatment for <12 years with lyme disease?
Amoxicillin
35
What is the treatment for lyme disease with neuro/cardiac involvement?
IV ceftriaxone
36
What is Kawasaki's disease?
Immune hyperreactivity causing systemic vasculitis
37
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)
```
38
What are the long term complications of Kawasaki's disease?
Coronary artery aneurysms
39
What are the investigations for Kawasaki's disease?
FBC (raised WCC, ESR, CRP)
| Echo (after 6/52 to check for cardiac aneurysms)
40
What is the treatment for Kawasaki's disease?
```
IVIG
Steroids
Ciclosporin
Infliximab
Aspirin (lower risk thrombosis)
Long term warfarin if severe coronary involvement
```
41
In which populations is Kawasaki's disease most common?
Japanese
| Afro-Caribbean
42
Which gene is Kawasaki's disease associated with?
ITPKC
43
What are the four species of malaria?
Falciparum
Ovale
Vivax
Malariae
44
What are the most significant complications of malaria, particularly in children?
Anaemia
| Cerebral oedema
45
What are the investigations for suspected malaria?
FBC
Urinalysis + MC&S
Thick and thin blood film
46
When do the symptoms of malaria become apparent?
7-10 days after innoculation
47
How does malaria present?
```
Swinging fevers (48-72 hours) - although not always
Malaise
Myalgia
Headaches
N&V&D
Jaundice
```
48
What is the treatment for malaria?
PREVENTION
Falciparum - quinine
Others - chloroquine
49
How is typhoid transmitted?
FO
| Salmonella typhi, paratyphi
50
How does typhoid present?
```
Worsening fever
Frontal headaches, cough, abdo pain,
Splenomegaly
Bradycardia
ROSE COLOURED SPOTS on trunk
```
51
How is typhoid diagnosed?
Blood cultures
52
What is the treatment for typhoid?
Cotrimoxazole
53
How is dengue transmitted?
Aedes anopheles mosquito
54
What are the severe symptoms of dengue?
Leukopenia
Thrombocytopenia
Haemorrhage
--> severe capillary leak syndrome
55
How does dengue fever present?
Fine, erythematous rash, headaches, myalgia
56
How is dengue diagnosed?
Viral antigen serology
57
How is dengue treated?
Fluid resus
| Monitoring
58
How is acute otitis media diagnosed?
Assessment of the tympanic membranes
59
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
60
What is the most common age group suffering from acute otitis media?
6-12 months
61
Why are babies and infants most at risk of acute otitis media?
Short, horizontal, poorly functioning eustachian tubes
62
What is acute otitis media often associated with?
Viral URTI - bacterial infection grows in viral fluid in ear
63
What is the most common cause of conductive hearing loss in children?
Otitis media with effusion (glue ear)
64
Why are neonates less likely to suffer from viral infection (and more likely bacterial)?
Passive immunity from mother
65
What is the CENTOR criteria for bacterial tonsillitis?
```
Cough absent
Exudate
Nodes
Temperature
Young OR old
```
66
What is the commonest causative organism of tonsillitis?
Group A beta haemolytic strep
67
What percentage of tonsillitis is bacterial?
1/3
68
When should abx be prescribed in tonsillitis?
CENTOR >3
69
Name a viral cause of tonsillitis?
EBV
70
How should tonsillitis be managed?
Penicillin/erythromycin (if bacterial)
Hospital admission if unable to E+D
Analgesia for pain/fever
71
How is tonsillitis diagnosed?
Clinically
| +/- throat swab, rapid Ag test
72
When is a tonsillectomy considered?
Recurrent bacterial tonsillitis
Peritonsillar abscess
Obstructive sleep apnoea
73
What are the features of epiglottitis?
Rapid onset fever >38.5
Drooling (unable to swallow secretions)
Quiet stridor
Sore throat
(Cherry red epiglottis)
74
How is epiglottitis managed?
DO NOT MOVE CHILD!!!!
Secure airway
Anaesthetist/ENT involvement
Blood cultures
IV ceftriaxone
Some children may respond to adrenaline/corticosteroids
Once extubated - PO coamox
75
What is the commonest causative organism in epiglottitis?
Hib
76
Acute otitis media mx
Admit if:
- Severe systemic infx
- Complications - masoiditis, meningitis
- <3 mos with T > 38
Paracetamol/ibuprofen for pain
Delayed abx prescription - only to be used if symptoms persist for more than 3 days.
Abx: amoxicillin 5-7 days
77
What is the usual course of otitis media?
3 days (but can last up to 1 week)
78
How is amoxicillin prescribed in acute otitis media?
Can be delayed (e.g. use if symptoms persist by or worsen before 3 days)
79
Do abx for otitis media have any effect on hearing loss?
No
80
Important considerations in children presenting with fever
Immunizations?
Ill contacts
Travel abroad
Community illnesses
81
Why do neonates rarely suffer from viral infections?
Passive immunity from mother
82
Septic screen
Blood culture
FBC (incl WCC differential)
Urine
CRP
+CXR
+LP
+Rapid antigen test
83
Abx in neonates
Cefotaxime
84
Abx for Listeria
Ampicillin
85
What should be considered if there is no obvious focus of infection?
Severe bacterial infection
| Or viral prodrome
86
Two commonest causative agents toxic shock syndrome
Toxin producing S.aureus
| Group A strep
87
Signs/symptoms TSS
High fever >39
Hypotension
Diffuse erythematous, macular rash - peeling skin
```
Mucositis - eyes, oral, genital.
GI - vomiting/diarrhoea
Renal
Liver
Clotting
CNS - altered consciousness
```
88
Mx of TSS
ICU
- IVI
- Abx (clinda, vanc)
- Vasopressor support
Surgical debridement of affected areas
89
Complications of TSS
Nec Fas
90
Which toxin does S.aureus produce?
PVL Panton Valentine Leukocidin
| -- SUPERANTIGEN
91
Causative agent in impetigo
S.aureus
92
Risk factors for impetigo
Pre-existing skin lesions, e.g. eczema
93
Impetigo Ix
Swabs
94
Impetigo Mx
Topical/PO flucloxacillin
Fusidic acid
HYGIENE +++ lots of hand washing to avoid autoinnoculation/spread to others
Do not go to nursey/school until the lesions are dry
95
Periorbital cellulitis causes
Spread from sinusitis or dental abscess.
Local trauma to skin
96
Periorbital cellulitis mx
Prompt IV abx (e.g. ceftriaxone)
Incision, drainage, culture may be necessary
97
Complications of periorbital cellulitis
Spread into orbit (order CT to check spread)
98
Toxin in staphylococcal scalded skin syndrome
Staphylococcus
99
Pathophysiology of SSSS
Separation of the epidermal skin through granular layers
100
SSSS features
Fever
Malaise
Purulent, crusting localised infection around eyes, nose and mouth with subsequent widespread erythema and tenderness of skin
Skin separates on gentle pressure
101
SSSS mx
Hospital admission
IV abx (fluclox)
Analgesia
Monitor hydration (similar to burns)
102
Hallmark of herpesviruses
After primary infection, virus becomes latent. Remains dormant in host.
Reactivation may occur after certain stimuli
103
Commonest form of HSV in children
Gingivostomatitis
104
Age of presentation gingivostomatitis
10 months to 3 years
105
Features gingivostomatitis
Vesicular lesions on lips, gums, anterior surfaces of tongue and hard palate
Becomes ulcerated and bleeds
High fever, miserable child
106
What route of administration of aciclovir should be used in chicenpox severe enough to warrant it?
IV
107
Which cells does the EBV virus attack?
B lymphocytes,
| Epithelial cells of the pharynx (hence sore throat)
108
Investigations for suspected EBV
Blood film - large atypical monocytes
Monospot test (heterophile antibodies)
Electrophoresis - IgM and IgG from seroconversion
109
Presentation of EBV
Malaise
Fever
Tonsilitis
Lymphadenopathy
Petechiae on soft palate
Hepatosplenomegaly
Maculopapular rash
110
Which abx should be avoided in pts with EBV?
Amox/Ampicillin - florid maculopapular rash
111
EBV mx
Supportive (paracetamol, fluids, bed rest)
PO pred and admission if upper airway obstruction
IVIG if active bleeding
112
What should pts with EBV be recommended to avoid for 8 weeks after?
Contact sports
113
How long should patients with EBV avoid contact sports for?
8 weeks
114
In which groups of patients is CMV particularly important?
Immunocompromised (incl. transplant recipients)
| The foetus
115
Treatment for CMV
IV ganclicovir
| PO valganciclovir
116
Complications of CMV
```
Retinitis,
Oesophagitis,
BM failure,
Colitis,
Pneumonitis
```
117
Presentation of CMV
Tends to be subclinical or mild
- Fever
- Malaise
118
Presentation of HHV6
- Fever
- Malaise
- Generalised macular rash (Roseola infantum (exanthem))
-- common cause of febrile convulsions
119
Mx of HHV6/7
Most resolve spontaneously over days/week
Paracetamol/ibuprofen
Fluids
120
Three ways parvovirus B19 is transmitted?
Respiratory
Vertical
Contaminated blood products
121
Presentation of parvovirus B19
Erythema infectiosum - SLAPPED CHEEK
Fever
Malaise
Headache
Arthralgia
122
Complications of parvovirus B19
Aplastic crisis.
Particular in children with high turnover of RBCs e.g. haemolysis (SCD, thalassaemia, G6PD) OR maliganancy (cannot fight infection)
123
Effect of parvovirus b19 on fetus
Hydrops fetalis
124
What type of virus causes hand, foot and mouth disease
Coxsackie A16
125
Presentation of measles
Fever
Malaise
Cough, coryza
Maculopapular rash starting on head/behind ears and spreading over body
Koplik's spots
126
Complications of measles
Encephalitis
Subacute sclerosis panencephalitis (7 years later)
Respiratory
127
Which vitamin deficiency is associated with a worser course of measles ?
Vitamin A
| PO Vitamin A if admitted
128
Treatment for measles
Notify Health Protection Unit
- Isolation
- Rest and fluids
- Paracetamol/ibuprofen
- Vitamin A PO (if admitted)
129
Where does the mumps virus replicate?
Epithelial cells of the respiratory tract
| Then into parotid glands
130
What time of year is mumps most common?
Spring
131
Presentation of mumps
Fever
Malaise
Parotitis (initially unilaterial then bilateral)
132
Incubation period of mumps
15-24 days
133
Most infective period of mumps
Within 7 days of parotitis
134
What might children with mumps complain of?
Ear ache (parotid swelling)
135
Which enzyme may be raised in mumps?
Amylase
136
What might abdominal pain in mumps indicate?
Pancreatic involvement
137
Mx mumps
Notify Health Protection Unit
- Isolation (don't go back to school until 5 days after parotitis)
- Rest and fluids
- Paracetamol/ibuprofen
138
Complications of mumps
Orchitis (uncommon in pre-pubertal boys)
Meningitis/encephalitis
139
Presentation of rubella
Maculopapular rash starting at head and working its way over body
Low grade fever
Suboccipital/postauricular lymphadenopathy
140
How is rubella diagnosis confirmed?
Serologically
141
Treatment for rubella (child)
Notify HPU
| Rest, fluids
142
Effect of rubella on fetus
Cataracts
| Cardiac (PDA)Deafness
143
When is the fetus most at risk of rubella?
First 8 weeks of pregnancy maternal infection
144
Commonest age Kawasaki's
6mos - 4 years
145
Who should not receive the BCG vaccination?
Immunosuppressed
146
How is TB spread?
Resp into lymphatic system
147
Where do children usually get TB from?
Infected adult in the household
148
Clinical features of TB
Fevers
Anorexia/weight loss
Cough
CXR features (e.g. bilateral hilar lymphadenopathy, apical consolidation)
149
Complications of TB
Miliary TB
TB meningitis
Coinfection with HIV
150
How is TB diagnosed?
Ideally sputum sample, but this can be difficult to obtain. Three consecutive morning gastric washings. Cultured for AFB.
Mantoux test
Interferon gamma release assays
CXR changes
Clinical features
151
How do interferon gamma release assays work?
Assess the respnse of T cells to specific antigen
152
What constitutes a positive mantoux test?
>10mm if no previoius BCG
| >15 mm if previous BCG
153
Which patients may show a false negative for a mantoux/IGRA test?
HIV - immunocompromise so do not mount immune response
154
Management of active TB
Notify HPU
RI for 6 months
PE for first 2 months
(+pyridoxine vB6 for isoniazid)
Contract tracing
155
How is latent TB managed?
3 months of rifampicin and isoniazid
156
Commonest route of transmission HIV
Mother to child transmission
- Intrauterine
- Intrapartum
- Postpartum (breastfeeding)
157
Which group of HIV positive patients should start ART asap? Why?
Infants - they have an increased risk of disease progression
158
How is HIV diagnosed (in <18mos and >18 mos)?
>18 mos HIV IgG Abs
<18 mos HIV DNA PCR
(infant will retain transplacental IgG Abs if infected mother, so not a good test) - 2x negative tests after first 3 months of treatment rules out HIV
159
What is the treatment for babies born to HIV+ mothers?
Zidovudine for 6 weeks
160
Clinical features of HIV in paeds
Mild - recurrent fevers, lymphadenopathy, parotitis, thrombocytopenia, hepatosplenomegaly
Moderate - Recurrent bacterial infx, candidiasis, chronic diarrhoea, lymphocytic pneumonia
AIDs - PCP, malignancy, severe FTT
161
What is the management of HIV in children?
```
HAART
Counselling incl family therapy
Nutrition
Weight and development monitoring
Vaccinations (no live vaccines)
Prophylaxis for opportunistic infx
```
162
What types of vaccines must not be given to HIV patients?
Live (e.g. BCG)
163
What factor increases the likelihood of vertical transmission of HIV?
Viral load in the mother (and CD4 count)
164
How is the risk of vertical transmission of HIV reduced?
Maternal/AN/PN ART - reduce viral load in mother to ideally undetectable before pregnancy/birth
Avoiding breast feeding
Avoiding PROM/instrumental delivery
Ideally a CS
165
What is the incubation period of lyme disease?
4-20 days
166
Eczema, thrombocytopenia, recurrent infections
Wiskott-Aldrich syndrome (WASP gene)
167
When is SCID likely to have been fatal by if undiagnosed?
3 years
168
Biochemistry SCID
Low T, B, Ig
