Paediatric Infectious Diseases Flashcards
What is Kawasaki disease?
main complication to be scared of
systemic, medium sized vessel vasculitis.
typically under 5
big complication is a coronary artery aneurysm.
clinical features of kawasaki disease
Persistent high fever (>39C) for more than 5 days. Key findings:
- Widespread erythematous maculopapular rash and desquamation (skin peeling) on palms and soles
- Strawberry tongue
- Red, cracked lips
- Cervical lymphadenopathy
- Bilateral conjunctivitis
Phases of kawasaki disease
Acute: Child most unwell with fever, rash and lymphadenopathy 1-2 weeks
Subacute: acute settle, desquamation and athralgia occurr and risk of coronary artery aneurysms. Lasts 2-4 weeks.
Convalescent stage: Symptoms settle and bloods return to normal. 2-4 weeks
Management of Kawasaki disease
High dose aspirin to reduce thrombosis risk
IV immunoglobulins to reduce risk of coronary artery aneurysm
Why is aspirin normally avoided in children
reyes syndrome risk
What is measles
RNA paramyxovirus, spread by aerosol transmission. Has a 10-14 day incubation period and patient is infective from prodrome until 4 days after rash start.
MMR Vaccine vaccinates against it
How does measles present
Prodrome
- Irritable, conjunctivitis, fever
Followed by main features
- Koplik spots (white spots (grains of salt) on the buccal mucosa) appear before the rash
- Rash (Starts behind ears (3-5 days post fever) and spreads to whole body. Discrete maculopapular rash that becomes blotchy and confluent. Desquamation typically spares palms and soles)
mx measles
Measles is self resolving 7-10 days post symptoms. Isolate until 4 days post symptom resolution
Notifiable disease to UKHSA
Vaccinate contacts within 72 hours
comps measles
Otitis media - most common
Pneumonia - most common cause of death
Encephalitis
Diarrhoea
Meningitis
Hearing loss
Vision loss
Death
what is scarlet fever?
Erythrogenic toxins produced by Group A haemolytic streptococci (Strep pyogenes), more common in kids 2-6 years, peak at 4.
Presents as widespread rough “sandpaper” rash following a Group A Strep infection (e.g. tonsilitis).
Spread via respiratory droplets
presentation of scarlet fever
2-4 day incubation period and presents with:
- Fever 24-48 hours
- Strawberry tongue
- Rash (fine punctuate erythema “pinhead” which appears first on torso and spreads, sparing palms and soles. Red-pink, blotchy, macular rash with rough “sandpaper” skin. Desquamination occurs)
- Cervical lymphadenopathy
- Flushed face, sore throat, malaise.
How is scarlet fever diagnosed and managed?
Throat swab to confirm
Oral Penicillin V for 10 days
Azithromycin alternative
Notifiable disease
Can return 24 hours after commencing antibiotics
Complications of scarlet fever
Usually mild but:
- Otitis Media (most common)
- Rheumatic fever
- Post streptococcus glomerulonephritis
are possible
What is rubella?
Rubella virus (part of togavirus family), highly contagious and spread via respiratory droplets. 2 week incubation. Infective from 7 days before symptoms to 4 days after rash
Presents with erythematous macular rash and is notifiable.
Children stay off school 5 days, avoid pregnant women
Presentation of rubella
Prodrome: low grade fever
Rash: Erythematous maculopapular rash initially on face before spreading to rest of body.
Lymphadenopathy: Suboccipital and postauricular
mx rubella
Supportive.
Notify UKHSA
Children stay off school and avoid pregnant women
Rubella in pregnancy can cause?
Congenital rubella syndrome
Damage most likely in 8-10 weeks
- Senisorineural deafness
- Congenital cataracts
- Congenital heart defects
- Cerebral palsy
- Hepatosplenomegaly
- Microphthalmia
(Deafness, blindness and congenital heart disease is a triad for this condition)
rubella
diagnosis
mx
IgM antibodies raised in mother.
Hard to distinguish from parovirus B19 clinically, so worth checking both.
Management
- Inform local health protection unit
- Advise non immunised to avoid rubella contacts,
What is parvovirus b19 ?
DNA virus which causes a range of clinical presentations.
Can go anywhere from mild fever to full rash.
Rash presents bright red on both cheeks (AKA Slapped cheek syndrome) before reticular rash appears over trunk and limbs. (rarely palms/soles)
As rash appears, child is no longer infectious.
A child with previously diagnosed parvorvirus B19 notices a recurrence of the rash. What can cause this and how is it treated?
Warmth (warm bath, heat, fever) can trigger rash again, but treatment and school exclusion are unnecessary
What patients are at particular risk from Parvovirus B19
Immunocompromised
Pregnant
Haematological conditions (sickle cell, thalassaemia, hereditary spherocytosis, haemoly
tic anaemia)
What does parvovirus B19 (slapped cheek syndrome) cause in pregnancy and how is it investigated
Miscarriage/fetal death
Severe fetal anaemia
Hydrops fetalis
Maternal pre-eclampsia like syndrome (hydrops fetalis, placental oedema, oedema in mother)
IgM to parvovirus (acute infection, last 4 weeks)
IgG parvovirus long term immunity
Rubella antibodies (Important differential!)
what is roseola infantum and its main complications
Caused by HHV-6 and HHV-7
High fever for 3-5 days, then disappears suddenly. Rash then appears for 1-2 days. Mild erythematous macular rash across legs, arms, trunk and face, not itchy.
Main complication is febrile convultions due to high temperature
If immunocompromised, GBS, myocarditis, thrombocytopaenia.
What is Zika caused by and what does it cause
Zika virus, spread by Aedes mosquito. Can be spread sexually.
Congenital Zika
- Microcephaly
- Fetal growth restriction
- Vetriculomegaly, cerebellar atrophy.
what does healed varicella pneumonia leave behind
calcific miliary opacities
dense with no uniform size
What is diptheria
Infection that causes fever, sore throat with grey pseudomembrane and lymphadenopathy. Vaccinated against in 6-in-1 vaccine (toxin vaccine).
Caused by Cornyebacterium diphtheriae which releases an exotoxin encoded by B-prophage, which inhibits protein synthesis by catalysing ADP-ribosylation of elongation factor 2 (EF2)
Presentation of diptheria
Recent visitor to Eastern Europe/Russia/Asia
Sore throat with “diphtheric membrane” - grey, pseudomembrane on posterior pharyngeal wall.
Bulky cervical lymphadenopathy
Neuritis
Can cause heart block
Diphtheric membrane on tonsils caused by necrotic mucosal cells. Systemic distribution can cause necrosis of myocardial, neural and renal tissue, causing heart block, neuritis, peripheral neuropathy (motor loss) etc
how is diptheria ix and mx
Throat swab and culture - using tellurite agar or Loeffler’s media
Managed with IM penicillin or diphtheria antitoxin
What is scalded skin syndrome?
A skin infection caused by Staph aureus in which exfoliative toxins (ETA and ETB) cause widespread erythema and blistering, which burst, causing desquamation that resemble burns.
The lesions do not affect mucosal surfaces, distinguishing it from TEN.
Presentation of scalded skin syndrome
Usually under 5
May be preceded by fever, irritability, malaise
Widespread erythema followed by large, flaccid blisters that easily rupture. These then peel (desquamation), resembling a scald.
Mucosal surfaces are UNAFFECTED
mx and comps of scalded skin syndrome
Managed with wound care (cleaning) supportive (hydration/fluid balance), and antibiotics (fluclox or vancomycin if MRSA)
Secondary infection (cellulitis/pneumonia) or dehydration and electrolyte imbalance are main concerns.
What is whooping cough
Gram negative bacterial infection Bortadella pertussis, typically presenting in children. Sometimes called 100 day cough
Notifiable disease.
Child has severe coughing fits in which child struggles to take air between coughs.
Vaccinated against but vaccine nor immunisation provide lifelong protection
Phases of whooping cough presentation
Catarrhal phase - 2 weeks (extremely contagious)
- low grade symptoms, fever, rhinorrhoea, cough.
Paroxysmal phase 1-6 weeks
- Uninterrupted “whooping” coughing that can result in vomiting, collapsed lung, broken ribs and apnoea
- O2 decrease can cause death
- Inspiratory whoop
- Usually worse at night or after feeding
Convalescent phase (healing)
- Cough subsides over weeks/months
Diagnostic criteria and ix of whooping cough
Unexplained acute cough >14 days + at least:
- Paroxysmal cough (Paroxysmal = in attacks/episodes)
- Inspiratory whoop
- Post-tussive vomiting
- Undiagnosed apnoeic attacks in children
Investigated for using
- Nasal swab culture for Bodetella pertussis
- PCR and serology
Mx of whooping cough
Notifiable, notify UKHSA
Oral macrolide (azithromycin, clarithromycin etc) if cough started within 21 days.
Oral prophylaxis for household contacts
School exclusion until 48 hours after starting antibiotics.
Comps of whooping cough
Symptoms usually resolve in 8 weeks but severe cough can cause damage:
Bronchiectasis!
Pneumonia
Rib fractures
Encephalopathy/Seziures
What is Polio
Poliomyelitis, caused by poliovirus. Spread through faeco-oral and respiratory routes.
Mainly affects kids’ nervous systems, can lead to paralysis.
Attacks the anterior horn cells of the spinal cord, causing flaccid paralysis.
Usually vaccinated in 6in1 (inactivated vaccine), so rare here but endemic in afghanistan, pakistan and nigeria.
Main concern with polio
Respiratory failure
Long term post polio syndrome, causing muscle weakness and fatigue for decades
Permanent paralysis
What is impetigo?
Superficial skin infection usually caused by Staph aureus or Strep pyogenes. Contagious, and children should be kept off school during disease course.
Can be primary or secondary to eczema, scabies, insect bites
Gold crust characteristic of Staph infection
Pathophysiology of impetigo
Can be bullous or non bullous - bullous is always staph aureus.
Non bullous
- Typically around nose/mouth, where exudate from golden crust. Does not cause systemic symptoms
Bullous
- Staph aureus produce epidermolytic toxins that break down proteins that hold skin together, forming 1-2cm vescicles that burst forming a golden crust. These eventually heal without scarring.
Bullous more common in neonates and children. When severe and widespread, it is called staphylococcal scalded skin syndrome.
Presentation of impetigo
“Golden Crust” from skin lesions typically found around mouth
Very contagious - stay off school!
Spread through itching of scabs
Mx of impetigo
Non-bullous/not systemically unwell - hydrogen peroxide 1% cream
Bullous
- Topical fusidic acid
- Topical mupriocin if fusidic resistant
Extensive disease
- Oral flucloxacillin
Keep off school until lesions are crusted/healed or 48 hours post starting Abx
comps of impetigo
Usually responds well to treatment but if not;
- Cellulitis
- Sepsis
- Scarring
- Post strep glomerulonephritis
- Staph scalded skin syndrome
- Scarlet fever
What is toxic shock syndrome, how does it present and how is it managed?
Caused by a severe systemic reaction to staphylococcal exotoxin TSST-1 superantigen toxin.
Previously caused by infected tampons
Presents with fever (>39C), hypotension, diffuse erythematous rash with desquamation, and involvement of 3 or more organ systems.
Managed with IV fluids and antibiotics
