Immunity and Infections Flashcards
What immunoglobulin is associated with first response adaptive immunity?
IgM
IgG for second response
What is included in the ‘5 in 1’ and when is it given?
DTaP (diptheria, tetenuss and pertussis), IPV and HiB
2 months, 3 months and 4 months
HiB also given at 12-13 months
DTaP and IPV also given at 2-3yrs (‘4 in 1’)
DT and IPV also given in teen years
When are Men C and Men B vaccines given?
Men B - 2 months, 4 months and 12-13 months
Men C - 2 months, 12-13 months
When is PCV (pneumococcal conjugate vaccine) given?
2 months, 4 months, 12-13 months
When is the MMR vaccine given?
12-13months, 2-3yrs
What is the Gardisil vaccine?
Vaccine against HPV 11 + 16 give to girl in their teen years
Why are some vaccines given several times and others not?
Live attenuated vaccines give good, long-term immuntiy e.g. MMR
Inactivated/sub-unit need ‘boosters/top-ups’
What are the bacterial causes on meningitis?
Streptococci Pneumoniae (gram +ve diplococci) Haemophilus Influenzae (gram -ve rods) Neisseria Meningitis (gram -ve diplococci) TB
What are the prodromes for viral/bacterial meningitis and what is meningism?
Viral - gi upset, pharyngitis
Bacterial - drowsiness
Meningism = stiff neck, photophobia, headache
Signs of raised ICP?
Irritability, drowsy/lethargic, high-pitched cry
What sign would indicate that meningitis has progressed to meningococcal septicaemia?
Non-blanching rash
What signs can you elicit from an infant with meningitis?
Kernings sign - resistance to knee extension with hip flexed (children>infants)
Brudninski’s sign - head flexion –> hip flexion
Tense fontanelle
What would you find when analysing the CSF in bacterial meningitis?
Cloudy appearance Opening pressure increased Low glucose Very high protein Some RBCs >WBCs (c/mm3)
When should you not do a LP in suspected meningitis?
Raised ICP is a contraindication
Can lead to coning - herniation of the brain stem through the foramen magnum –> paralysis and respiratory inhibition
Management of bacterial meningitis?
In GP - gie benzylpenecillin IM (<1yr = 300mg, 1-9yrs = 600mg, 10+ = 1.2g)
In hospital - ceftriaxome (80mg/kg/day) then indicated Abx after culture
Can give steroids (dexamethasone) to reduce inflammation
Complications associated with meningitis?
Hydrocephalus
subdural effusion\acute adrenal failure
deafness
cerebral palsy +/- learning difficulties (10%)
What are pupura?
Bleeding in the dermis –> purple spots/nodules that do not blanch
Non-thombocytopenic causes of purpura?
Meningococcal septicaemia
HSP
Hypertensive states
Trauma
Thrombocytopenic causes of pupura?
Immune thombocytopenic pupura (ITP) - often preceded by vrial infection e.g. CMV in <1yr
Coagulation disorders - disseminated intra-vascular coagulation (DIC) and scurvy (vit C difficiency)
Leukaemia
Management of ITP?
Steroids and immunoglobulins
What gram +ve cause of septicaemia are babies at risk of when they are <48hrs and >48hrs old?
> 48hrs = Staphylococcus - aureus, coagulase -ve
<48hrs = group B streptococci (pneumoniae)
What are the symptom of septicaemia?
Fevers, rigors, sweating SOB Poor feeding Non-blanching rash lethargy
Investigations for septicaemia?
Septic screen: Bloods - FBC, U+E's, culture LP - culture, glucose, cell count Urine - MSU, culture Stool - culture, virology CXR
Broad spectrum management of specticameia in <3months and >3months?
<3 months - cefotaxime +/- amoxacillin
>3months - ceftriaxone
What causes chicken pox?
Varicella zoster virus (VZV) - typically affects 4-10yrs old
When is chicken pox infectious?
4 days before rash until it has all scabbed over (~1 week)
Symptoms of VZV?
Prodrome - fever, coryza, cough
2 days later –> Characteristic vesicular rash (macule–>papule–>vesicle) on face and trunk
Management of chicken pox?
Supportive - fluids, calpol/paracetamol
Advise to not scratch / cut child’s nails
Use cold baths and calamine ointment to relive itching
If immunocompromised give aciclovir and anti VZV immunoglobulin
If they have superimposed infection give flucloxacillin
What is conjunctivitis?
Inflammation of the conjuctiva - viral, bacterial and allergic
Red eyes + discharge:
Viral - watery/sticky +/- lymphoid aggregates
bacterial - thick yellow/green
Allergic - watery/clear, itchy/gritty eyes
What specific causes are there for neonates?
Gonoccocal conjunctivitis +/- chlamydia infection
= red eyes +/- lid swelling + purulent discharge
Complications = corneal rupture/hazing
Sticky eyes (staph/pseudomonas/strep) - treat with topical neomycin
Management of bacterial conjunctivitis?
Chloramphenicol in most cases (+cefotaxime IM stat in neonatal gonococcal)
What is infectious mononucleosis?
Aka glandular fever - caused by Epstein-Barr virus
What are the symptoms of glandular fever?
Fever, malaise, lethargy Sore throat --> tonsillitis Weight loss/anorexia Cough Nausea Photophobia
What are the signs for glandular fever?
Cervical lymphadenopathy Petechiae on the soft palate maculopapular rash Spleno/hepatomegaly Jaundice
What investigations can be done in suspected infectious mononucleosis?
Bloods: FBC (atypical lymphocytes)
Monospot test (checks for heterophile Abs) is positive in 60% cases (often -ve in infants)
Virology - will show IgM early –> IgG
Complications of infectious mononucleosis?
Concomitant group A streptococcus tonsillitis - treat with amox/ampicillin
Burkitt’s lymphoma (if immunocompromised)
What age group are usually affected by egg/milk allergy?
Infants - they are likely to grow out of this
What are the majority of allergies mediated by?
IgE mediated e.g. peanut allergy
Primary = from birth
Secondary = acquired (usually milder)
What type of allergy is coeliac’s?
Non-IgE mediated - delayed presentation, insidious onset
Symptoms of mild and severe allergic reactions?
Mild - urticaria, itching, facial swelling
Severe - angioedema, wheeze/stridor, abdo pain/vomiting, collapse
Investigations for allergies?
IgE - skin prick test, RAST (blood test for specific IgE groups)
Non-IgE - avoidance of food types
What are the symptoms of measles?
Prodrome - irritable, conjunctivitis, fever
Sign before rash = koplik’s spots - white spots on buccal mucosa
3 C’s - cough, coryza, conjunctivitis
Fever (often >40)
Rash - maculopapular (appears behind ear–> rest of body)
Management of measles?
A NOTIFIABLE DISEASE
Anti-viral = ribavarin
MMR vaccine should have been given - to all contacts <72hrs
What complications can occur due to measles?
Immediate - Diarrhoea, bronchopneumonia, acute otitis media, febrile convulsion
Corneal ulceration, increased incidence of appendicitis, myocarditis
Encephalitis ~1 week later (1/5000) - headache, irritability, drowsy - 15% mortality
Sub-acute Sclerosing Panencephalitis (SSPE) - 1/100,000 - 4-10yrs after infection - progressive neurological dysfunction
What is Kawasaki’s disease?
A systemic vasculitis - more common in Japanese/Caribbean
Symptoms of Kawasaki’s?
Prolonged fever >5 days (characteristically resistant
+/- >1 of the following:
Non-purulent conjunctivitis
Red mucus membranes (can have red swollen tongue = strawberry tongue)
Cervical lymphadenopathy
Rash
Red swollen palms/soles and finger/toe peeling
Can also have GI upset - diarrhoea and reduced appetite
Investigations in kawasaki’s?
Bloods - ESR, CRP
Echocardiogram - check for coronary artery aneurysm (complication of kawasaki’s)
ECG - look for any conduction abnormalities
Management of Kawasaki’s
High dose aspirin + immunoglobulins:
- High dose immunoglobulin stat - 2g/kg (only given within 10 days of onset of symptoms)
- Aspirin - high dose until fever subsides, lower anti-platelet dose for 6 weeks
Severe = infliximab/ciclosporin
Symptoms of peri-orbital cellulitis?
Peri-orbital oedema and erythema
Fever
Investigations for peri-orbital cellulitis?
CT head - check infection spread and brain involvement
LP - exclude meningitis
Complications of peri-orbital cellulitis?
Orbital cellulitis - proptosis, painful eye movements, reduced visual acuity
Meningitis
Abscess formation
Cavernous sinus thrombosis
At what age will Abs to HIV appear in the blood of a baby who has been exposed to HIV at birth?
18 months
Maternal Abs detected prior to 18 months only incurs exposure to the virus
What is rubella syndrome?
Congenital infection –> deafness, microcephaly, cataracts and PDA (= reason for vaccination given)
Symptoms of rubella -diagnostic?
Child generally well/low-grade fever
Maculopapular rash - starts on face then spreads centrofugally (fades 3-5 days) - not itchy in children
Not clinically diagnostic - need seroloy
Hand, foot and mouth disease
Self-limiting disease common in <10yrs:
- Mild systemic upset
- oral ulcers
- vesicles on palms and soles of feet
Management:
- Reassurance - no link to cow disease
- Hydration and analgesia
- Can go to nursery/school if feeling well enough to do so
Impetigo management
Localised disease:
- Topical fusidic acid - first line
- Topical retapamulin - 2nd line
- Topical mupirocin - MRSA
Systemic disease
- Flucloxacillin
- Clarithromycin if penicillin allergic
Complications of impetigo
Cellulitis Lymphadenitis SSSS scarlet fever post-streptococcal glomerulonephritis
HSP
Florid, non-blanching purpura
IgA mediated hypersensitivity vasculitis
50-90% have preceding URTI
Rash starts as erythematous macules –> raised and purpuric in 24 hrs
Other symptoms:
arthralgia/arthritis
Abdominal pain - colicky
Testicular pain
Self-limiting but give NSAIDS +/- steroids
Complications of HSP
Renal involvement
Intussusception
GI bleeding
Pulmonary haemorrhage
25% have recurrent symptoms
