Infection

Question 1

Features of measles

Answer 1

Rash
Think of C’s, conjunctivitis, coryza,
“Koplik spots”.
2 week incubation

Question 2

Features of meningococcal septicaemia

Answer 2

A petechial rash of sudden onset is associated with septicaemia

Treat urgently with antibiotic

Question 3

Summary of thread worms?

Answer 3

Occurs after swallowing eggs in environment

Perianal itching, particularly at night
Girls may have vulval Sx
Asymptomatic in 90%

Apply Sellotape to perianal area send for microscopy to see eggs, but most pt’s treated empirically

Hygiene measures
Single dose of mebendazole for all members of household

Question 4

Causes of meningitis?

Answer 4

<3mnths: GBS, e coli, Gr-, listeria monocytogenes

1mnth-6yrs: Neisseria meningitidis (meningococcus), s pneumonia, h influenzae

> 6yrs: Neisseria meningitidis, s pneumoniae.

Question 5

Features of meningitis?

Answer 5

<3mnths, irritability, general lethargy, poor feeding + fevers.

Seizures

Photophobia, neck stiffness rare, high index of suspicion for meningitis in generally unwell infant

Non-blanching petechial rash.

Question 6

Investigation for meningitis?

Answer 6

CI to LP: any signs of ↑ICP, focal neurological signs, papilledema, bulging of fontanelle, DIC, signs of cerebral herniation. Meningococcal septicaemia.

Blood cultures

PCR

Question 7

Management of meningitis?

Answer 7

<3 mnths: IV amoxicillin + IV cefotaxime. Don’t give steroids.

> 3 mnths: IV cefotaxime/ceftriaxone.

Dexamethasone: if, frankly purulent CSF, CSF WBC >1000/ microlitre, ↑CSF WBCC with protein conc >1g/L bacteria on Gr strain.

Abx prophylaxis of contacts: ciprofloxacin

Question 8

What is roseola infantum?

Answer 8

a common disease of infancy caused by the human herpes virus 6 (HHV6).

It has an incubation period of 5-15 days

typically affects children aged 6 months to 2 years.

Question 9

Features of roseola infantum?

Answer 9

high fever: lasting a few days, followed later by a
maculopapular rash

Nagayama spots: papular enanthem on the uvula and soft palate

febrile convulsions occur in around 10-15%

diarrhoea and cough are also commonly seen

Other possible consequences of HHV6 infection
> aseptic meningitis
> hepatitis

School exclusion is not needed.

Paracetamol + ibuprofen

Question 10

What is mumps?

Answer 10

caused by RNA paramyxovirus

tends to occur in winter and spring

Spread:

• by droplets
• respiratory tract epithelial cells → parotid glands → other tissues
• infective 7 days before and 9 days after parotid swelling starts
• incubation period = 14-21 day

MMR vaccine: the efficacy is around 80%

Question 11

Features of mumps?

Answer 11

fever

malaise, muscular pain

parotitis (‘earache’, ‘pain on eating’): unilateral initially then becomes bilateral in 70%

fever disappears within 3-4 days

Question 12

Management of mumps?

Answer 12

rest

paracetamol for high fever/discomfort

notifiable disease

Question 13

Complications of mumps?

Answer 13

orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis

hearing loss - usually unilateral and transient

meningoencephalitis

pancreatitis

Question 14

Investigations of mumps?

Answer 14

Plasma amylase ↑ = pancreatic involvement

Pos salivary mumps IgM

Question 15

Management of mumps?

Answer 15

No Tx, rest, paracetamol, notifiable disease.

Exclusion from school or work for 5 days of swollen glands

Question 16

What is measles?

Answer 16

RNA paramyxovirus

spread by droplets

infective from prodrome until 4 days after rash starts

incubation period = 10-14 days

rarely seen in developed world following adoption of immunisation programmes

Question 17

Features of measles?

Answer 17

prodromal phase = irritable,
conjunctivitis, fever

Koplik spots = typically develop before the rash, white spots (‘grain of salt’) on the buccal mucosa

rash = starts behind ears then to the whole body, discrete maculopapular rash becoming blotchy & confluent, desquamation that typically spares the palms and soles may occur after a week

diarrhoea occurs in around 10% of patients

Question 18

Investigations for measles?

Answer 18

IgM antibodies can be detected within a few days of rash onset

Question 19

Management of measles?

Answer 19

mainly supportive - simple analgesia

admission may be considered in immunosuppressed or pregnant patients

notifiable disease → inform public health

School exlcusion: 4 days after rash develop

Question 20

Complications of measles?

Answer 20

otitis media: the most common complication

pneumonia: the most common cause of death
encephalitis: typically occurs 1-2 weeks following the onset of the illness)

subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness

febrile convulsions

keratoconjunctivitis, corneal ulceration

diarrhoea

increased incidence of appendicitis

myocarditis

Question 21

Managing contacts of measles?

Answer 21

if a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection)

this should be given within 72 hours

Question 22

What is erythema infectiosum?

Answer 22

‘slapped cheek syndrome’

Common in children, rarer in adults, but more serious

Only spread to others 3-5 days before rash appears

Parvovirus B19

Question 23

Features of slapped cheek syndrome?

Answer 23

↑temp

Runny nose + sore throat

Headache

Bright red rash, both cheeks, look as if been slapped.

Adults don’t usually get rash.

Few days later, lighter rash on chest, arms, legs, skin raised + itchy. Rarely involved palms + soles.

Question 24

Complications of slapped cheek syndrome?

Answer 24

Child begins to feel better as rash appears + rash peaks after a wk then fades. For mnths after, bath, sun, heat, fever trigger recurrence of red cheeks + rash.

Question 25

Management of slapped cheek syndrome?

Answer 25

Self limiting, better in 3wks. Paracetamol/ ibruprofen.

See GP: pregnant (miscarriage), sickle cell (aplastic crisis, supress erythroporesis for a wk) thalassaemia (severe anaemia), weakned immune system.

No school exclusion

Question 26

Other presentations of parvovirus B19?

Answer 26

asymptomatic

pancytopenia in immunosuppressed patients

aplastic crises e.g. in sickle-cell disease
parvovirus B19 suppresses erythropoiesis for about a week so aplastic anaemia is rare unless there is a chronic haemolytic anaemia

hydrops fetalis
parvovirus B19 in pregnant women can cross the placenta in pregnant women
this causes severe anaemia due to viral suppression of fetal erythropoiesis → heart failure secondary to severe anaemia → the accumulation of fluid in fetal serous cavities (e.g. ascites, pleural and pericardial effusions)
treated with intrauterine blood transfusions

Question 27

What is Scarlet fever?

Answer 27

a reaction to erythrogenic toxins produced by Group A haemolytic streptococci (usually Streptococcus pyogenes).

It is more common in children aged 2 - 6 years with the peak incidence being at 4 years.

spread via the respiratory route by inhaling or ingesting respiratory droplets or by direct contact with nose and throat discharges, (especially during sneezing and coughing).

Question 28

Features of scarlet fever?

Answer 28

Incubation period of 2-4 days

fever: typically lasts 24 to 48 hours

malaise, headache, nausea/vomiting

sore throat - can appear 1-2 days after tonsillitis

‘strawberry’ tongue

rash:
> fine punctate erythema (‘pinhead’) which generally appears first on the torso and spares the palms and soles
> children often have a flushed appearance with circumoral pallor. The rash is often more obvious in the flexures
> it is often described as having a rough ‘sandpaper’ texture
> desquamination occurs later in the course of the illness, particularly around the fingers and toes

Question 29

Diagnosis of scarlet fever?

Answer 29

a throat swab is normally taken but antibiotic treatment should be commenced immediately, rather than waiting for the results

Question 30

Management of scarlet fever?

Answer 30

oral penicillin V for 10 days

patients who have a penicillin allergy should be given azithromycin

children can return to school 24 hours after commencing antibiotics

scarlet fever is a notifiable disease

Question 31

Complications of scarlet fever?

Answer 31

otitis media: the most common complication

rheumatic fever: typically occurs 20 days after infection

acute glomerulonephritis: typically occurs 10 days after infection

invasive complications (e.g. bacteraemia, meningitis, necrotizing fasciitis) are rare but may present acutely with life-threatening illness

Question 32

What is coxsackie virus?

Answer 32

Hand, foot, mouth

Caused by intestinal virus of picornaviruses (coxsackie A16 + enterovirus 71).

Very contagious

typically occurs in outbreaks at nursery

Question 33

Features of hand, foot and mouth disease?

Answer 33

mild systemic upset: sore throat, fever

oral ulcers

followed later by vesicles on the palms and soles of the feet

Question 34

Management of hand, foot and mouth disease?

Answer 34

symptomatic treatment only: general advice about hydration and analgesia

reassurance no link to disease in cattle

children do not need to be excluded from school
the HPA recommends that children who are unwell should be kept off school until they feel better
they also advise that you contact them if you suspect that there may be a large outbreak.

Question 35

What is chicken pox?

Answer 35

caused by primary infection with varicella zoster virus.

Shingles is a reactivation of the dormant virus in dorsal root ganglion

Highly infectious

spread via the respiratory route

can be caught from someone with shingles

infectivity = 4 days before rash, until 5 days after the rash first appeared*

incubation period = 10-21 days

Question 36

Features of chicken pox?

Answer 36

fever initially

itchy, rash starting on head/trunk before spreading. Initially macular then papular then vesicular then crust and fall off

systemic upset is usually mild

more sever in older children/adults

Question 37

Management of chicken pox?

Answer 37

supportive

keep cool, trim nails

calamine lotion

school exclusion: NICE Clinical Knowledge Summaries state the following: Advise that the most infectious period is 1–2 days before the rash appears, but infectivity continues until all the lesions are dry and have crusted over (usually about 5 days after the onset of the rash).

immunocompromised patients and newborns with peripartum exposure should receive varicella zoster immunoglobulin (VZIG). If chickenpox develops then IV aciclovir should be considered

Question 38

Complications of chicken pox?

Answer 38

secondary bacterial infection of the lesions -NSAIDs may ^ risk, single infected area/small area of cellulitis, invasive group A streptococcal soft tissue infections may occur > necrotising fasciitis

pneumonia

encephalitis (cerebellar involvement may be seen)

disseminated haemorrhagic chickenpox

arthritis, nephritis and pancreatitis may very rarely be seen

Question 39

What is neonatal sepsis?

Answer 39

a serious bacterial or viral infection in the blood affects babies within the first 28 days of life.

Neonatal sepsis is categorised into early-onset (EOS, within 72 hours of birth) and late-onset (LOS, between 7-28 days of life) sepsis

account for 10% of all neonatal mortality

Male:female incidence 1:1

Incidence of neonatal sepsis: 1-5 per 1000 live births
Term neonates: 1-2 per 1000 live births
Late pre-term infants: 5 per 1000 live births
Birth weight <2.5kg: 0.5 per 1000 live births

Black race is an independent risk factor for group B streptococcus-related sepsis

Question 40

Causes of neonatal sepsis?

Answer 40

The overall most common causes of neonatal sepsis are group B streptococcus (GBS) and Escherichia coli, accounting for approximately two thirds of neonatal sepsis cases

Early-onset sepsis in the UK is primarily caused by GBS infection (75%)
Infective causes in early-onset sepsis are usually due to transmission of pathogens from the mother to the neonate during delivery

Late-onset sepsis usually occurs via the transmission of pathogens from the environment post-delivery, this is normally from contacts such as the parents or healthcare workers
Infective causes are more commonly coagulase-negative staphylococcal species such as Staphylococcus epidermidis, Gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella and Enterobacter, and fungal species

Other less common causes include:
Staphylococcus aureus
Enterococcus
Listeria monocytogenes
Viruses including herpes simplex and enterovirus

Question 41

Risk factors for neonatal sepsis?

Answer 41

Mother who has had a previous baby with GBS infection, who has current GBS colonisation from prenatal screening, current bacteruria, intrapartum temperature ≥38ºC, membrane rupture ≥18 hours, or current infection throughout pregnancy

Premature (<37 weeks): approximately 85% of neonatal sepsis cases are in premature neonates

Low birth weight (<2.5kg): approximately 80% are low birth weight

Evidence of maternal chorioamnionitis

Question 42

Presentation of neonatal sepsis?

Answer 42

Respiratory distress (85%) = Grunting, Nasal flaring, Use of accessory respiratory muscles, Tachypnoea

Tachycardia: common, but non-specific

Apnoea (40%)

Apparent change in mental status/lethargy

Jaundice (35%)

Seizures (35%): if cause of sepsis is meningitis

Poor/reduced feeding (30%)

Abdominal distention (20%)

Vomiting (25%)

Temperature: not usually a reliable sign as the temperature can vary from being raised, lowered or normal
Term infants are more likely to be febrile
Pre-term infants are more likely to be hypothermic

The clinical presentation can vary from very subtle signs of illness to clear septic shock

Frequently, the symptoms will be related to the source of infection (e.g. pneumonia + respiratory symptoms, meningitis + neurological symptoms)

Question 43

Investigations for neonatal sepsis?

Answer 43

Blood culture

FBC - abnormal neutrophil count

CRP - help to guide management

Blood gases - metabolic acidosis is particularly concerning for neonatal sepsis, particularly a base deficit of ≥10 mmol/L

Urine MC&S - more useful in LOS, show signs of infection (^ leukocytes, positive culture, haematuria, proteinuria) if urosepsis

Lumbar puncture - if suspecting meningitis as source of infection

Question 44

Management of neonatal sepsis?

Answer 44

intravenous benzylpenicillin with gentamicin as a first-line regimen for suspected or confirmed neonatal sepsis - unless local bacterial resistance patterns disagree

CRP measured to monitor progress

antibiotics can be ceased at 48 hours in neonates who have CRP of <10 mg/L and a negative blood culture at presentation and at 48 hours

Normally, in neonates with culture-proven sepsis, duration will be approximately 10 days

O2, fluid and elctrolytes

severely ill neonates may need volume and/or vasopressor support

prevention/management of hypoglycaemia

prevention/management of metabolic acidosis