Paediatric Infectious Diseases

Question 1

What is Kawasaki disease?

main complication to be scared of

Answer 1

systemic, medium sized vessel vasculitis.

typically under 5

big complication is a coronary artery aneurysm.

Question 2

clinical features of kawasaki disease

Answer 2

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

Question 3

Phases of kawasaki disease

Answer 3

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

Question 4

Management of Kawasaki disease

Answer 4

High dose aspirin to reduce thrombosis risk

IV immunoglobulins to reduce risk of coronary artery aneurysm

Question 5

Why is aspirin normally avoided in children

Answer 5

reyes syndrome risk

Question 6

What is measles

Answer 6

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

Question 7

How does measles present

Answer 7

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)

Question 8

mx measles

Answer 8

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

Question 9

comps measles

Answer 9

Otitis media - most common
Pneumonia - most common cause of death
Encephalitis
Diarrhoea
Meningitis
Hearing loss
Vision loss
Death

Question 10

what is scarlet fever?

Answer 10

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

Question 11

presentation of scarlet fever

Answer 11

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.

Question 12

How is scarlet fever diagnosed and managed?

Answer 12

Throat swab to confirm
Oral Penicillin V for 10 days
Azithromycin alternative
Notifiable disease
Can return 24 hours after commencing antibiotics

Question 13

Complications of scarlet fever

Answer 13

Usually mild but:
- Otitis Media (most common)
- Rheumatic fever
- Post streptococcus glomerulonephritis

are possible

Question 14

What is rubella?

Answer 14

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

Question 15

Presentation of rubella

Answer 15

Prodrome: low grade fever

Rash: Erythematous maculopapular rash initially on face before spreading to rest of body.

Lymphadenopathy: Suboccipital and postauricular

Question 16

mx rubella

Answer 16

Supportive.

Notify UKHSA

Children stay off school and avoid pregnant women

Question 17

Rubella in pregnancy can cause?

Answer 17

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)

Question 18

rubella
diagnosis
mx

Answer 18

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,

Question 19

What is parvovirus b19 ?

Answer 19

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.

Question 20

A child with previously diagnosed parvorvirus B19 notices a recurrence of the rash. What can cause this and how is it treated?

Answer 20

Warmth (warm bath, heat, fever) can trigger rash again, but treatment and school exclusion are unnecessary

Question 21

What patients are at particular risk from Parvovirus B19

Answer 21

Immunocompromised
Pregnant
Haematological conditions (sickle cell, thalassaemia, hereditary spherocytosis, haemoly
tic anaemia)

Question 22

What does parvovirus B19 (slapped cheek syndrome) cause in pregnancy and how is it investigated

Answer 22

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!)

Question 23

what is roseola infantum and its main complications

Answer 23

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.

Question 24

What is Zika caused by and what does it cause

Answer 24

Zika virus, spread by Aedes mosquito. Can be spread sexually.

Congenital Zika
- Microcephaly
- Fetal growth restriction
- Vetriculomegaly, cerebellar atrophy.

Question 25

what does healed varicella pneumonia leave behind

Answer 25

calcific miliary opacities

dense with no uniform size

Question 26

What is diptheria

Answer 26

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)

Question 27

Presentation of diptheria

Answer 27

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

Question 28

how is diptheria ix and mx

Answer 28

Throat swab and culture - using tellurite agar or Loeffler’s media

Managed with IM penicillin or diphtheria antitoxin

Question 29

What is scalded skin syndrome?

Answer 29

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.

Question 30

Presentation of scalded skin syndrome

Answer 30

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

Question 31

mx and comps of scalded skin syndrome

Answer 31

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.

Question 32

What is whooping cough

Answer 32

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

Question 33

Phases of whooping cough presentation

Answer 33

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

Question 34

Diagnostic criteria and ix of whooping cough

Answer 34

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

Question 35

Mx of whooping cough

Answer 35

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.

Question 36

Comps of whooping cough

Answer 36

Symptoms usually resolve in 8 weeks but severe cough can cause damage:

Bronchiectasis!
Pneumonia
Rib fractures
Encephalopathy/Seziures

Question 37

What is Polio

Answer 37

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.

Question 38

Main concern with polio

Answer 38

Respiratory failure
Long term post polio syndrome, causing muscle weakness and fatigue for decades
Permanent paralysis

Question 39

What is impetigo?

Answer 39

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

Question 40

Pathophysiology of impetigo

Answer 40

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.

Question 41

Presentation of impetigo

Answer 41

“Golden Crust” from skin lesions typically found around mouth
Very contagious - stay off school!
Spread through itching of scabs

Question 42

Mx of impetigo

Answer 42

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

Question 43

comps of impetigo

Answer 43

Usually responds well to treatment but if not;
- Cellulitis
- Sepsis
- Scarring
- Post strep glomerulonephritis
- Staph scalded skin syndrome
- Scarlet fever

Question 44

What is toxic shock syndrome, how does it present and how is it managed?

Answer 44

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