Paeds Infectious Diseases

Question 1

Causes of Scarlett Fever

Most common in children 2-6 peak at 4Y

Answer 1

• Spread by resp droplets
• Toxins produced by Group A strep

Question 2

Signs & Symptoms Scarlett fever

Answer 2

• Fever 24-48h
• Malaise, headache, vomitting
• Strawberry tongue
• punctate erythema rash on torso
• Pallor with flushed appearance
• sandpaper texture rash

no conjunctivitis so different to kawasaki

Question 3

Investigations & Management Scarlett Fever

Answer 3

• throat swab
• Oral Penicillin for 10 days
• Notifiable disease
• Can return to school after 24h of Abx commencement

Question 4

Complications Scarlett Fever

Answer 4

• 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 5

Kawasaki Disease Pathophysiology

boys are more affected than girls; peak age at 1. Most common cause of acquired heart disease in children in the UK.

Answer 5

• type of vasculitis which is predominately seen in children

Question 6

Kawasaki Disease Signs and Symptoms

Answer 6

• high-grade fever which lasts for > 5 days. Fever is characteristically resistant to antipyretics
• conjunctival infection (bilateral)
• bright red, cracked lips
• strawberry tongue
• cervical lymphadenopathy
• red palms of the hands and the soles of the feet which later peel
• erythematous maculopapular rash and desquamation (skin peeling) on the palms and soles.

Complications: coronary artery aneurysm

Children are often irritable and miserable, and have a high fever that is difficult to control

Question 7

Kawasaki Disease Investigations & Management

No specific diagnostic test

IgG may be raised for certain infxns

Answer 7

• high-dose aspirin
• IV immunoglobulin
• ECHO for coronary artery aneurysm detection

PIMS: add corticosteroid too

Kawasaki disease is one of the few indications for the use of aspirin in children. Due to the risk of Reye’s syndrome aspirin is normally contraindicated in children

Question 8

Measles Pathophysiology

RNA paramyxovirus

outbreeaks occur due to insufficient vaccine uptake in some parts of the world.

Answer 8

Virus is an RNA virus that is transmitted via droplets and infects the epithelial cells of the nose and conjunctiva. Primary viraemia occurs 2-3 days after infection, and virus continues to replicate over next few days.

Infective 4 days before to 4 days after onset of rash.

Typically occur in preschool and young children with peak incidence in the late winter or spring

Question 9

Measles Signs And Symptoms

3 phases

Answer 9

1. prodromal phase
   * irritable
   * conjunctivitis
   * fever
2. Koplik spots
   * typically develop before the rash
   * white spots (‘grain of salt’) on the buccal mucosa
3. 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

COMPLICATIONS
Encephalitis occurs in 1 in 5000 cases, a few days after the onset of illness. Mortality is 15% - serious long-term sequelae include seizures, deafness, hemiplegia and severe learning difficulties.
Subacute sclerosing panencephalitis (SSPE) is a rare but devastating illness manifesting 7 years after infection on average in about 1 in 100,000 cases. Caused by measles virus variant which persists in the CNS.
Can also lead to acute otitis media (around 10% of cases) and lower respiratory tract infxn, Febrile convulsions, pneumonia (most common cause of death)

Question 10

Measles Investigations and Management

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

Answer 10

• mainly supportive
• admission may be considered in immunosuppressed or pregnant patients
• notifiable disease → inform public health

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) within 72h

Question 11

lifelong immunity

Chicken Pox (varicella zoster) Pathophysiology

Primary varicella zoster infxns

Answer 11

• Highly contagious infection that is spread through direct contact with the lesions or through infected droplets from a cough or sneeze
• 10d -3wks incubation
• Infectious period begins 2 days before vesicles appear
• no longer infectious after crusted leisons

Question 12

Chicken Pox Signs and Symptoms

Answer 12

• Fever initially
• widespread rash – erythematous, raised, vesicular, blistering lesions.
• Usually starts on the trunk or face and spreads outwards affecting the whole body over 2-5 days.
• Lesions progress through stages: papule, vesicle, pustule, crusting.
• May also have headache, anorexia, signs of upper respiratory tract infection, fever and itching

recover after 2wks

Question 13

Chicken Pox Management & Investigations

Answer 13

• Usually self-limiting with symptomatic treatment of fever and itching.
• Children should be kept off school. until leisons are crusted
• Immunocompromised children should be treated with intravenous aciclovir initially

Complications
* 2ndry bacterial ifxn: due to group A strep - toxic shock syndrome NSAIDS Increase risk
* Encephalitis
* Pnuemonitis
* Cerebro stroke
* Shingles (rare in childhood)

Question 14

Rubella

AKA german measels

Infxn with togavirus - rare now due to vaccinations

Answer 14

• the incubation period is 14-21 days
• low grade fever, maculopapular rash on face before spreading to whole body 5 days
• lymphadenopathy: suboccipital and postaurricular
• Tx: Supportive MMR Vaccine as supportive.

Complications are rare in childhood but may develop arthritis, myocarditis, encephalitis or thrombocytopenia.
- Can severely damage fetus of a preganant woman: deafness, cataracts, heart disease, learning disability
- in first 8-10 weeks risk of damage to fetus is as high as 90%, rarely any damage after 16wks
- suspected cases of rubella in pregnancy should be discussed with the local Health Protection Unit

Question 15

. Most cases are now generally in those unvaccinated

Diphtheria signs & Symptoms

Gram positive bacterium Corynebacterium diphtheriae

releases an exotoxin encoded by a β-prophage inhibiting protein synthesis. Causes a diphtheric membane on tonsils caused by necrotic mucosal cells.

Answer 15

• Respiratory diphtheria: sore throat, low-grade fever, dry cough and an adherent pseudomembrane covering tonsils and the mucosa of the pharynx, larynx and the nose. eyes, ears, or genitals may be affected. Grey, pseudomembrane on the posterior pharyngeal wall
• Cutaneous diphtheria is usually a mild disease causing cutaneous sores or shallow ulcers.

can lead to heart block or neuritis

Recent travel to EE, Russsia or Asia is RF

Question 16

Diphtheria Investigations & Management

Answer 16

Investigations
culture of throat swab: uses tellurite agar or Loeffler’s media
Management
intramuscular penicillin
diphtheria antitoxin

Diphtheria is now included in the UK vaccination programme, with doses given at:
- 2 months – 6-in-1 vaccine
- 3 months – 6-in-1 vaccine
- 4 months – 6-in-1 vaccine
- 3 year, 4 months – 4-in-1 vaccine
- 14 years – diphtheria, tetanus, polio vaccine

Question 17

U5’s

Staphylococcal Scalded Skin Syndrome

Epidermolytic Toxic Release from Staph Auerus

Answer 17

• Toxins break down Proteins in skin (proteases) which hold skin together. Damages skin. Adults develped immunity to these toxins
• Fever, Malaise, Purulunt, crusting infxn of eyes. Separation of epidermis and formation of blisters which burst and give sore skin
• Untreated can lead to sepsis& prone to dehydration
• IV Abx (flucloxacillin) 500mg/QDS
• Electrolyte balance important

Need to rule out burns as can look very similar.

Question 18

infants under 6 months with suspect pertussis should be admitted

Pertussis ( whooping Cough)

Gram -ve Bordetella Pertusis

Women who are between 16-32 weeks pregnant will be offered the vaccine.

Answer 18

• 2-3 days of Coryza then coughing bouts leading to vomit
• Inspiratory whoop
• Spells of Apnoea
• Cough can last 14 days
• PCR for B.pertusis
• Notifiable disease
• Oral Carithromyosin, erythromyocin.
• household contacts should be offered antibiotic prophylaxis
  antibiotic therapy has not been shown to alter the course of the illness
• Child can return to school 48hr after commencing Abx or 21 days after infection of no Abx

infants are routinely immunised at 2, 3, 4 months and 3-5 years. Newborn infants are particularly vulnerable, which is why the vaccination campaign for pregnant women was introduced
- Infection or Vaccination does not guarantee lifelong protection.

Question 19

Faeco-Oral transmission

poliomyelitis AKA Polio

Caused by Poliovirus

Characterised by muscle weakness and permanent paralysis.

Answer 19

• Muscle Weakness, Permanent paralysis in some cases (unilateral, proximal limbs, legs over arms). Alot of aymptomatic cases or fever, aches non specific symptoms in some cases.
• Minor illeness: D&V, sore throat
• PCR for detection
• No treatment, in rich countries: inactivated poliovirus vaccine
• Oral to GI Tract where it invades CNS - destruction of motor neurone

Question 20

often becomes latent inchildhood

Tuberculosis in Childhood

Infection with mycobacterium tuberculosis

Spread by droplet, bacilli remain at entry site and some travel to lymph nodes. Bacilli multiply at both sites. spread then via blood and lymphatics. Infection at this point may become dormant

Answer 20

As immune system responds to spreading infection (3-6 weeks later) systemic symptoms develop:
- Fever
- Anorexia and weight loss
- Cough
Reactivation may present as localised disease or may be widely disseminated (miliary TB) to sites such as bones, joints, kidneys, pericardium and CNS. Children particularly prone to tuberculous meningitis.
* Mantoux test - tuberculin skin test.
* Inteferon Gamma release essays

Complications: Pneumothroax or pleural effusions

Management RIPE for two months (3mths if Millary)
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
After Two months
- Decreased to just isoniazid and rifampicin for a further 4 months.

Question 21

Major routes of transmission are mother-to-child,

HIV in Children

Clinical presentation varies with the degree of immunocompromise. Those with mild degree may only have lymphadenopathy or parotid enlargement; if moderate there may be recurrent bacterial infections, candidiasis, chronic diarrhoea and lymphocytic interstitial pneumonitis.
Severe degree = lots of pportunistic infections

Answer 21

• In children over 18 months, HIV infection diagnosed by detecting antibodies against the virus.
• Preferred starting therapy is two nucleoside/nucleotide reverse transcriptase inhibitors plus one of a ritonavir-boosted protease inhibitor, a non-nucleoside transcriptase inhibitor or an integrase inhibitor. Goal to suppress viral load to undetectable. Majority of infected children survive to adulthood with effective treatment.

Question 22

MENINGOCOCCAL DISEASE

by Neisseria meningitidis, colonising the nasopharynx

Meningococcal meningitis is when the bacteria is infecting the meninges and the cerebrospinal fluid around the brain and spinal cord.
Bacterial infection of the meninges usually follows septicaemia but can be isolated.

Answer 22

• fever, neck stiffness, vomiting, headache, photophobia, altered consciousness and seizures.
• Infants often do not have classical symptoms and therefore there is lower threshold for suspicion.
• Can also present with non-blanching rash
• Brudzinski sign positive in meningitis – flexion of neck with child supine causes flexion of knees and hips
• Kernig positive – flexion of hips and knees in supine child causes pain in back on knee extension
• Lumbar puncture performed with suspected meningitis (all children under 3 months with a fever should have this) unless there is suspicion of raised ICP, will delay antibiotics or is contraindicated for another reason.

Commuity: IM Benzylpenicillin
Hospital: IV Ceftriaxone + amoxicillin (cover for listeria)
Dexamathesone also given

Question 23

Encephalitis

may occur in those who are not vaccinated: polio mumps rubella & measles

• most common virus being herpes simplex virus.

Answer 23

• Inflammation of the brain parenchyma (meninges may also be affected).
• with fever, altered consciousness and often seizures.
• LP with Viral PCR
• Antiviral treatment: Accyclovir in HSV or VZV
• Ganivlovir in CMV

Question 24

5th disease

Erythema Infectiosum AKA Slapped cheek

Infection with human parvovirus B19 (HPV-B19).

Transmission is via respiratory secretions, vertical transmission from mother to fetus or transfusion of infected blood products

Answer 24

• mild fever, noticeable rash which looks like slapped cheek
• rose red rash, may spread to rest of body minus soles & palms
• Can cause acute arthritis
• Virus can affect new born baby in childhood (first 20wks of pregnancy) - hydrops fetalis

sunlight or heat can trigger recurrence of symotoms

Parovirus can also
* cause aplastic crisis in sickle cell,
* hydrops fetalis: 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 Intruterine blood transfusions.

Question 25

yelolow crusts aound lips

Impetigo

Localised, highly contagious skin infxn caused by staphys or strep

Nasal carriage is often the source of infection.
Impetigo can be classed as non-bullous (Nose and mouth) or bullous impetigo caused by staphy also has golden crust

Answer 25

• Impetigo occurs when bacteria enter via a break in the skin;
• Clin diagnosis - Bacterial culture of exudate
• Hydrogen perozide 1% cream
• Topical Abx (fusidic acid)

Extensive disease
* oral flucloxacillin
* oral erythromycin if penicillin-allergic

children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment

Question 26

multiorgan involvement

Staphylococcal toxic shock syndrome

Staphylococcal toxic shock syndrome describes a severe systemic reaction to staphylococcal exotoxins,

Answer 26

• fever: temperature > 38.9ºC
• hypotension: systolic blood pressure < 90 mmHg
• diffuse erythematous rash
• desquamation of rash, especially of the palms and soles
• involvement of three or more organ systems: e.g. gastrointestinal (diarrhoea and vomiting), mucous membrane erythema, renal failure, hepatitis, thrombocytopenia, CNS involvement (e.g. confusion)

Management
* removal of infection focus (e.g. retained tampon)
* IV fluids
* IV antibiotics

Question 27

common in u10

Hand Foot & Mouth

Coxsackie A virus

Virus is spread via direct contact with throat discharges, saliva, vesicle fluid or faecal material from an infected person.

Answer 27

• Typical URTI
• 1-2 days later small mouth ulcers appear followed by blistering red spots on hands feet and mouth
• supportive care; hydration and analgesia
• ## Children do not need to be excluded

Question 28

common in u10

Hand Foot & Mouth

Coxsackie A virus

Virus is spread via direct contact with throat discharges, saliva, vesicle fluid or faecal material from an infected person.

Answer 28

• Typical URTI
• 1-2 days later small mouth ulcers appear followed by blistering red spots on hands feet and mouth
• supportive care; hydration and analgesia
• ## Children do not need to be excluded

Question 29

Mumps features

RNA paramyxovirus

Complications
* 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

Answer 29

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

• rest
• paracetamol for high fever/discomfort
• notifiable disease