Infectious diseases Flashcards
When are Koplik spots found?
Measles
24-48 hours before the exanthem
What are the stages of subacute sclerosing panencephalitis?
- Dementia
- Epilepsy and myoclonus
- Decerebration (increased tone, vegetative state, coma)
What is the treatment for scabies?
Permethrin
Wash all clothing and linen
When are renal ultrasounds indicated for UTIs?
Severe UTI
Recurrent febrile UTIs
Atypical UTI (i.e. non-E.coli)
Children younger than 2 with a febrile UTI
For structural abnormalities
Why are pregnant women vaccinated for pertussis?
To provide passive immunity to their children
What is the triad of Reye syndrome?
- Preceding viral illness
- Acute encephalopathy
- Liver failure
* Due to aspirin use in children with a viral infection*
How long is a patient with scarlet fever infectious for?
24 hours after penicillin is given
How does the rash of meningococcus progress?
Red rash → petechiae → purpura
What vaccinations are given at 4 years?
Diptheria, tetanus, pertussis, polio
What is Brudzinski sign?
Pain and hip flexion with passive neck flexion

What bacteria is the most common cause of osteomyelitis?
Staphylococcus auerus
When is a child with erythema infectiosum contagious?
During the prodrome only
Which TORCH infection is associated with Hutchinson teeth, a congenital dental malformation involving notches and widely shaped central incisors?
Syphilis

What vaccinations are given at 4 months?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
Pneumococcal
Rotavirus
What is the pathophysiology of DIC secondary to sepsis?
Cytokines → hypercoagulation with hypofibrinolysis → microthrombi → impaired perfusion and tissue necrosis
What chemoprophylaxis is given to people who have had contact with Neisseria meningitidis?
Ciprofloxacin oral
OR
Ceftriaxone IM (hurts)
Contacts within the past week
Which TORCH infection is associated with saddle nose and a short maxilla?
Syphilis

What vaccination is given at birth?
Hepatitis B
How do meningococci stain?
Gram negative diplococci
Passive infant immunity through breast milk occurs through which immunoglobulin?
IgA
What is the most common cause of meningitis in newborns?
Group B Streptococcus
What drug can be given for RSV prevention?
Palivizumab
Monoclonal antibody that provides passive immunisation to RSV infection
Indications: infants at risk for severe bronchiolitis e.g. prematurity, heart or lung disease, immunocompromised states
Monthly IM administration during RSV season for the first year of life
What does a non-blanching rash in children suggest?
Meningococcal
What is the major complication of measles?
Subacute sclerosing panencephalitis
A lethal, generalised, demyelinating inflammation of the brain
A sandpaper rash is characteristic of which disease?
Scarlet fever
What is the treatment for Staphylococcus impetigo?
Flucloxacillin
Which TORCH infection is associated with CN VIII deafness?
Syphilis
How is meningococcus spread?
Secretions from the back of the nose and throat
Requires close and prolonged contact, not easily spread
Bacteria do not last long outside of the body
Which TORCH infections present with a blueberry muffin appearance, indicative of extramedullay haematopoesis?
Rubella + CMV

Which organism causes pertussis?
Bordetella pertussis
Is tonsillitis more commonly viral or bacterial?
Viral
If bacterial - S. pyogenes (Group A strep)
What is the most common cause of croup?
Parainfluenza virus (75%)
Followed by respiratory syncytial virus
What is the pathophysiology of Waterhouse-Friderichsen syndrome?
Bacterial endotoxins → coagulopathy → haemorrhagic necrosis of the adrenal gland
What features are suggestive of pyelonephritis in a child with bacteriuria?
Fever
Loin pain
Tenderness
If any of these features are present treat as pyelonephritis (common in children)
Gastroenteritis that occurs in an outbreak is most likely?
Norovirus
Which population is predisposed to eczema herpeticum?
Atopic people

Which TORCHes infection presents with recurrent infections and diarrhoea?
HIV
What is the triad of congenital rubella?
- Patent ductus arteriosus
- Cataracts
- Deafness
What causes hand, foot and mouth disease?
Coxsackie A
What vaccinations are given at 6 weeks?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
Pneumococcal
Rotavirus
What cause scabies?
Sarcoptes scabiei mite
Do premature infants recieve their vaccinations at chronological or corrected age?
Chronological
When are Pastia’s lines seen?
Scarlet fever
Most pronounced in the groin, underarm and elbow creases
What is the most common cause of meningitis in children and teens?
Neisseria meningitidis
Why do infants with bronchiolitis have hyperinfilation in CXR?
Mucous plugs act as a one way valve → air goes in but not out → air-trapping and hyperinflation
Viral infection followed by extension of commensals from the larynx into the trachea describes which disease?
Bacterial tracheitis
What cardiovascular defects are associated with congenital rubella?
Patent ductus arteriosis
Pulmonary artery hyperplasia
What are the three most suggestive signs of sepsis from meningococcal disease?
- Cold hands and feet
- Leg pain
- Abnormal skin colour e.g. pallor, mottling
What is the tetrad of HSP?
- Palpable purpura
- Arthritis/arthralgia
- GI symptoms
- Renal disease
What are the TORCH infections?
T - toxoplasmosis
O - others; syphilis, varicella zoster, parvovirus B19, listeriosis
R - rubella
C - cytomegalovirus
H - herpes simplex
How is tonsillitis treated?
Supportive
Antibiotics only used in groups at risk of complications of S. pyogenes infection e.g. high rates of rheumatic fever, existing heart disease
Which TORCH infection is associated with saber shins?
Syphilis

Sharp anterior bowing of the tibia
When is the peak incidence of bronchiolitis?
2-6 months of age
Primarily affects children <2
More common in winter
Which pathogen is most commonly involved in otitis media?
S. pneumoniae
Bacterial superinfection following URTI
How is hand, foot and mouth disease treated?
Supportive
Hygeiene
Lesions are contagious until they dry up
How is Kawasaki disease treated?
IV immunoglobulin
High dose aspirin
Which pathogen may cause meningitis with myalgia and a petechial/purpuric rash?

Neisseria meningitidis
How is a diagnosis of epiglottitis confirmed?
Pharyngoscopy
Cherry-red epiglottis
Not needed for a diagnosis
What causes the induction of prostaglandins, particularly PGE2, during fever?
Pyogenic cytokines arriving at the anterior hypothalamus
Why is the rash from meningococcal sepsis non-blanching?
Neisseria meningitidis has direct toxicity to the endothelium of blood vessels → bleeding into the skin
What are the distinctive clinical features of a child with epiglottitis?
Tripoding
Drooling
Muffled voice with painful speech
Distress
What is the classic triad of congenital toxoplasmosis?
- Chorioretinitis
- Hydrocephalus
- Intracranial calcifications
What vaccinations are given in year 7?
Diptheria, tetanus, pertussis
Human papillomavirus (2 doses)
What are the features of Kawaski disease?
C - conjunctivitis
R - rash
A - adenopathy
S - strawberry tongue
H - hands and feet (oedema and erythema)
and burn
What are the 3 C’s of measles?
Conjunctivitis
Cough
Coryza
What is the major complication of Kawasaki disease?
Coronary artery aneurysm
When does Forchheimer sign occur?
Rubella
Petechiae on the soft palate and uvula during the prodromal period
What is the most common causative agent of bacterial tracheitis?
Staphylococcus aureus
Which TORCHes infection presents with hearing loss, seizures, petechial rash and blueberry muffin rash?
CMV
What is the most common cause of gastroenteritis in young children?
Rotavirus
How long is a child with rubella infectious for?
1-2 weeks before the rash appears → 5 days after
What are 3 risk factors for bronchiolitis?
- Prematurity
- Congenital heart disease
- Congenital lung disease
- Immunodeficiency
When is a child with varicella zoster contagious?
24 hours before the rash until all crusted
What follow up imaging is performed if a renal ultrasound is suggestive of vesiculoureteric reflux?
Micturating cystourethrogram
What vaccinations are given at 12 months?
Meningococcal ACWY
Pneumococcal
Measles, mumps, rubella
What is the immediate treatment if meningococcal meningitis is suspected?
IV ceftriaxone/cefotaxime
What vaccination is given in years 10-11?
Meningococcal ACWY
What vaccinations are given at 18 months?
Diphtheria, tetanus, pertussis
Measles, mumps, rubella, varicella
Haemophilus influenzae type b
Palivizumab is used to prevent what disease?
Bronchiolitis (RSV)
What are the two most common causes of meningitis in infants (1 month - 2 years)
- Streptococcus pneumoniae*
- Neisseria meningitidis*
Which antibiotic is used for otitis media?
Amoxicillin
Indications: bilateral infection, symptoms not resolving, severe illness, immunosuppression
What is the most common cause of bronchiolitis?
Respiratory syncytial virus
What is erythema marginatum?
Cutaneous manifestation of rheumatic fever
Centrifugally expanding pink rash with a well-defined outer border and central clearing
Non-pruritic
What is the classic triad of meningitis?
Fever, headache, neck stiffness
Which TORCH infection often presents with foetal hydrops?
Parvovirus
Due to aplastic anaemia
What causes roseola?
Herpes virus 6
What is the formal name for croup?
Laryngotracheitis
Where does the rash of measles spread on the body>
Cephalocaudal
Which TORCH infection presents with encephalitis and herpetic (vesicular) lesions?
HSV-2
What causes eczema herpeticum?
Herpes simplex 1/2
Where does the rash from rubella start?
Behind the ears
How is acute cystitis treated?
Trimethoprim + sulfamethoxazole
5 days (10 days for pyelonephritis)
Does vomiting predominate in rotavirus or norovius?
Norovirus
Diarrhoea is more severe in rotavirus
What imaging finding is characteristic of croup?
Steeple sign (subglottic narrowing)

What is Kernig sign?
Pain with leg flexion in meningitis

Why is dexamethasone given to infants with meningitis?
Reduces the risk of hearing loss (Hib) and may improve mortality (pneumococcus)
Thought to reduce the overwhelming inflammatory response to administration of antibiotics - give before antibiotics
How is eczema herpeticum treated?
Oral acyclovir
Dermatologic emergency
What vaccinations are given at 6 months?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
How is encephalitis treated?
Acyclovir
In case the cause is HSV - rare but devestating
What is the characteristic x-ray sign of epiglottitis?
Thumbprint sign
Enlarged epiglottis with supraglottic narrowing

What causes impetigo?
Staphylococcus aureus
Group A B-haemolytic Streptococcus if low SES
How does Streptoccocus pneumoniae (pneumococci) stain?
Gram positive diplococci

What causes scarlet fever?
TOXINS from Group A Streptococcus
What type of immunoglobulin can cross from maternal blood into the placenta?
IgG
What are the most common causes of viral meningitis?
Enterovirus: coxsackie and echovirus
Herpes simplex
EBV
More common in teens and young adults
Less severe than bacterial meningitis and a full recovery can be expected
What is the most common cause of Waterhouse-Friderichsen syndrome?
Meningococcal meningitis
(Neisseria meningitidis)
Why do infants with bronchiolotis have atelectasis on CXR?
Mucous plugs trap air in the bronchioles → air diffuses into the bloodstream → airways collapse
How is herpetic gingivostomatitis managed?
Supportive management with analgesia
Acyclovir if immunocompromised

When is dexamethasone given during the treatment of meningitis?
Before administration of Abx
Prevents overwhelming inflammatory response
What immunisation is given at birth?
Hepatitis B
What immunisations are given at 6 weeks?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
Pneumococcal
Rotavirus
What immunisations are given at 4 months?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
Pneumococcal
Rotavirus
What immunisations are given at 6 months?
Diptheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, polio
What immunisations are given at 12 months?
Meningococcal ACWY
Pneumococcal
Measles, mumps, rubella
What immunisations are given at 18 months?
Diptheria, tetanus, pertussis
Measles, mumps, rubella, varicella
Haemophilus influenzae type b
What immunisations are given at 4 years?
Diptheria, tetanus, pertussis, polio
What immunisations are given in year 7?
Diptheria, tetanus, pertussis
Human papillomavirus (2 doses)
Give three ways by which GAS infection can be confirmed (current or recent)
- Throat culture
- Rapid streptococcal antigen test
- Antistreptolysin antibody
- Antideoxyribonuclease B antiboody
What are the major criteria for rheumatic fever?
- Carditis
- Arthritis
- Chorea
- Erythema marginatum
- Subcutaneous nodules
What are anti-deoxyribonuclease B antibodies tested for?
Group A strep
Which vaccines are live-attenuated?
MMR
Rotavirus
Varicella
Zoster
Yellow fever
Tyhoid
Japanese encephalitis
BCG
Does SSSS involved the mucosa?
NO
How is Sydenham’s chorea treated?
Usually no treatment
Carbamazepine or valproic acid, if necessary
Following acute rheumatic fever, how long is secondary prevention with benzathine penicillin continued for?
3-4 weekly
Minimum of 10 yearts after more recent episode or until age 21 (whichever is longer)
Which organism often causes infection following fresh water exposure?
Pseudomonas aeruginosa
What are the most common causes of ophthalmia neonatorum?
Conjunctivitis in the first month of life
Chlamydia or gonorrhoea
What are the possible complications of meningitis?
SIADH
Cerebral oedema
Hearing loss
Waterhouse-Friderischsen syndrome
Epilepsy
Cognitive deficits, CP
How many annual URTIs is normal for a young child?
8-10
What is cat scratch disease?
Benign, self-limiting illness caused by Bartonella henselae, transmitted by cats
Mild constitutional symptoms, papules/vesicles, lymphadenopathy

Which helminth causes threadworm/pinworm?
Enterobius vermicularis
Which medication is in Combantrin?
(anti-helminth chocolates)
Pyrantel
What is the triad of infectious mononucleosis?
- Fever
- Generalised non-tender lymphadenopathy
- Exudative pharyngitis/tonsilitis
Which childhood vaccination is associated with febrile seizures?
MMR