Paed Infection Flashcards
Definition of paed sepsis
SIRS + suspected / proven infection
Symptoms of paed sepsis
Fever or hypothermia Cold hands / feet mottled Prolonged cap refill time Chills / rigors Limb pain Vomiting Diarrhoea Muscle weakness Muscle / joint aches Skin rash Diminished urine output Tachycardia Tachypnoea Leucocytosis or leukocytopenia
What is bacteraemia?
Bacteria multiplying in the blood stream
Definition of paed severe sepsis
SEPSIS + multi organ failure + 2 of the following - resp failure - renal failure - neurological failure - haematological failure - liver failure ARDS Septic shock
What does ARDS stand for?
Acute respiratory response syndrome
What is ARDS?
Inflammatory response of the lungs
Which gender gets sepsis more?
B > G
Responsible pathogens for paed meningitis in neonates < 1 month
Group B streptococci
E coli
Listeria monocytogenes
Responsible pathogens for paeds meningitis in children
Streptococcus pneumoniae
Meningococci
Haemophilus influenzae
Meningitis +/- sepsis symptoms in children / neonates
nuchal rigidity headaches photophobia diminished consciousness focal neurological abnormalities Seizures In neonates - lethargy - irritability - bulging fontanelle - 'nappy pain'
Treatment for paeds meningitis +/- sepsis
Supportive ABCD Causative treatment - Ax with good penetration in CSF and broad spec - 3rd gen cefalosporins (amoxicilline if neonates) Chemoprophylaxis - close household contacts - meningococcus B and strep B
Investigations of paed meningitis + / - sepsis
Bloods - FBC, leucocytosis, thrombocytopenia - CPR ; elevated - blood gas; metabolic acidosis - glucose; hypoglycaemia CSF - pleocytosis, increased protein level, low glucose Blood and CSF cultures (antigen testing, PCR) Urine culture, skin biopsy culture Imaging - CT cerebellum
What is streptococcus pneumoniae?
Gram +ve duplo-cocci
Where does strep pneumoniae colonise?
upper airways
- 5-10% adults
- 20-40% children
How is strep pneumoniae transmitted?
Droplets
What are predisposing factors for invasive disease in step pneumoniae?
Viral infections
Complications of pneumococcal meningitis
Brain damage
Hearing loss
Hydrocephalus
Where can pneumococcal disease colonised / invade and cause?
Otitis media Sinusitis Meningitis Septicaemia Arthritis / osteomyelitis Peritonitis Empyema Pneumonia
What is haemophilus influenzae B?
Gram - ve bacterium
What can haem influenza B cause?
Bacteraemia
Meningitis (as severe as pneumococcal meningitis)
Pneumonia
Epiglottitis
What are predisposing factors for disease in haemophilus influenzae type B?
Viral infections
How does meningococcal disease spread through the body?
meningococcus in nasopharynx passage through the epithelia Meningococcus in blood stream - < 12 hours signs of septic shock - < 18-36 hours signs on meningitis
Prognosis of meningococcal disease
Case fatality rate 5-15% 50% of deaths in first 12 hours, 80% within 48 hours Long term morbidity in the significant proportion of survivors - amputation (14%) - skin scarring (48%) - cognitive impairment - epilepsy - hearing loss
Virulence factor of meningococcal disease
Endotoxin = lipooligosaccharide
Associated endotoxin levels and mortality
Features of streptococci
Gram +ve cocci
Penicillin
No resistance issues
Features of staphylococci
Gram +ve cocci Flucloxacillin (= synthetic penicillin resistant to B-lactamases) Resistance big issue MRSA carriers
Causative organisms of scarlatina (scarlet fever)
Reaction to toxins produced by Group A B-haemolytic streptococci
exclusively STREP PYOGENES
Presentation of scarlet fever
Malaise Fever Tonsilitis then start exanthema STRAWBERRY RED TONGUE Squamation (hands and feet)
Incubation of scarlet fever
2-4 days
Who is protected from scarlet fever?
< 2 y/o relatively protected
> 10 y / o natural protection in 80%
Virulence factors of scarlet fever
M protein
Exotoxins
Complications of scarlet fever
Erysipelas Cellulitis Impetigo Streptococcal toxic shock Rheumatic fever 0.3-3% Glomerulonephritis
Treatment of scarlet fever
Penicillin 10 days
Causative organisms of impetigo
S pyogenes
S aureus
Presentation of impetigo
highly contagious
sores and blisters
no systemic symptoms
yellow brown crustae
Causative organisms of SSSS
Exotoxins of S aureus
Who does SSSS usually affect?
< 5 y/o
particularly in newborns
Presentation of SSSS
Fever widespread redness fluid filled blisters rupture easily, especially the skin folds
Presentation of Kawasaki disease
Fever for at least 5 days 4 / 5 of.... - bilateral conjunctival injection - changes of the mucous membranes - cervical lymphadenopathy - polymorphous rash - changes of the extremities Peripheral oedema Peripheral erythema Periungual desquamation
What is Kawasaki disease?
Self limited vasculitis of medium sized arteries
Who gets Kawasaki disease?
All racial and ethnic groups
highest prevalence in japan and Hawaii
increased risk in siblings and twins
Treatment of Kawasaki disease
To prevent complications like vasculitis coronary arteries
- immunoglobulins
- aspirin
- other immunosuppressive agents
What conditions are a persistent fever and rash associated with?
Infection
Henoch-shonlein purpura
Vasculitis (skin, kidneys, more rare GI tract)
Assosiated with previous aspecific viral illness
What causes erythematous and maculopapulous vesicular rashes and fever?
Measles Rubella Enterovirus Cytomegalovirus Human Herpes virus 6 + 7 Parovirus B19 EBV
What causes a vesiculobullous vesicular rash and fever?
VZV
HSV
Enteroviruses
What causes petechial and purpuric vesicular rashes and fever?
Rubella (congenital)
enterovirus
CMV (congenital)
Types of varicella zoster virus infections
Primary infection - varicella - chickenpox Recurrent infection - zoster
Incubation period of VZV
14 (10-21) days
Presentation of VZV
Mild malaise and fever initially Kids are NOT sick Exanthema - papules -> vesicles -> pustules -> crustae -> scarring -> new lesions during 5-7 days Rash starts on trunk and scalp itching
Complications of VZV
secondary strep/staph infections skin (10-15%) (NSAIDs increase risk)
Meningoencephalitis
Cerebellitis
Arthritis
Treatment of VZV
Aciclovir
- indications
Prevention of VZV
Vaccination (active/passive)
Varicella zoster immunoglobulin for
- newborns peripartum exposure
- immunocompromised patients
Severe complications of VZV
Death
T cell deficiencies
Warning signs of severe VZV
high fever
new lesions > day 10
inflamed lesions
general malaise
What is HSV caused by?
HS1 - oral
HS2 - genital
Presentation of HSV
Stomatitis (primary infection)
Recurrent cold sores
Complications of HSV
Kerato conjunctivitis
Encephalitis
Systemic neonatal infections
immunocompromised children
treatment of HSV
Self limiting acyclovir
How do neonates catch HSV?
Birth canal
Direct contact
When does HSV appear in neonates?
Day 4 - 21 of life
Presentation of HSV in neonates
70-80% disseminated/ CNS infections - sepsis - meningoencephalitis - hepatitis (jaundice, bleeding) 20-30% skin / eye / mouth (SEM disease) High mortality
Causative organisms of hand-foot-mouth disease
Enterovirus 71
Coxsackie A16
Incubation of hand foot mouth disease
3 - 6 days
Who gets hand foot mouth disease?
< 10 y/o
When do you get hand foot and mouth disease?
Summer and early autumn
Presentation of hand-foot-mouth disease
Mild systemic upset - sore throat - fever Exanthema and enanthema Painful lesions Vesicles in mouth and on palms of soles and feet
How long does recovery take in hand foot mouth disease?
5 - 10 days
Presentation of mild enteroviral disease
Fever +/- rash Hand, foot and mouth disease Herpangina Pleurodynia Pharyngitis Conjunctivis Croup
Presentation of potentially severe enteroviral diseases
Meningitis Encephalitis Acute paralysis Neonatal sepsis Myocarditis/pericarditis Hepatitis Chronic infection in immunocompromised patients
Investigations of vesicular rashes
Clinical Smear of vesicle (ulcer base) - Tznack test; no differentiation HSV/VZV PCR (fluids, CSF, blood) Serology (past infections only)
What infections cause vesicular rashes?
Varicella zoster
Herpes simplex
Enterovirusess
What does Kawasaki disease need to be differentiated from?
S pygoenes infections
What are primary immunodeficiencies?
Rare, chronic disorders in which part of the bodys immune system is missing or functions improperly
What are primary immunodeficiencies caused by?
Single gene defects
What are secondary immunodeficiencies?
Components of the immune system are all present and functional, but acquired diseases affecting the immune system and/or treatment negatively influencing the immune system
Examples of causes of secondary immunodeficiencies
HIV infection
Patients treated for malignancies
Types of primary immunodeficiencies
Antibody deficiencies
Cellular immunodeficiencies
Innate Immune disorders
What are antibody deficiencies characterised by?
Deficiency of one or more (sub)classes of antibodies (e.g. IgA, IgG, IgM) due to defective B-function
Absence of mature B cells
Recurrent bacterial infections of the upper and/or lower resp tract
S pneumoniae, H influenzae
What are cellular immunodeficiencies characterised by?
Impaired T cell function or the absence of normal T cells
Unusual or opportunistic infections often combined with failure to thrive
Pneumocytic jirovecci
Features of innate immune disorders
Defects in phagocyte function Complement deficiencies Absence or polymorphisms in pathogen recognition receptors Defects in phagocyte function - s aureus - aspergillus Complement deficiencies - n meningitidis
Signs of primary immunodeficiencies vs just an infection
Severe - requires hospitalisation or IV Ax
Persistent - wont completely clear up or clears up very slowly
Unusual - caused by an uncommon organism
Runs in the family
- similar susceptibility to infection
Investigations of a membrane attack complex
Measurement of complement activation and/or individual factors
Presenting Symptoms of paediatric HIV/AIDs
recurrent common childhood RTIs Persistent oral thrush Erythematous popular rash Generalised lymphadenopathy Recurrent / disseminated VZV/HSV infections Failure to thrive Developmental delays Oppertunistic infections ; CMV, pneumonia / retinitis
Genetics of chronic granulomatous disease
65% X linked
35% autosomal recessive
Presentation of chronic granulomatous disease
Life threatening recurrent severe bacterial and fungal infections
Life time incidence of invasive aspergillosis 25-40% and main cause of death 35%
Curative option of chronic granulomatous disease
HSCT
Investigation of chronic granulomatous disease
DHR test
What is the presenting symptom of primary immunodeficiency?
Invasive fungal infections
Who are invasive fungal infections seen in?
Children with neutropenia due to leukaemia and/or chemotherapy
Invasive candidiasis in prem neonates due to immature (but physiological) immune system
In children admitted to PICU and treated with broad spec Ax and or abdo surgery
What type of fungi is candida?
Endogenous
How do you catch candida?
Birth canal
Hands of health care workers
What can candida cause?
Candidaemia
What type of fungi is aspergillus?
Exogenous
How do you catch aspergillus?
Air
Water
Environment
Blood cultures candida vs aspergillus
Candida = positive Aspergillus = negative
What birth weight is most common for neonatal candidemia?
< 750g
Mortality of neonatal candidaemia
20-40%
Presentation of neonatal candidaemia
Sepsis syndrome
2/3rd week of life
Thrombocytopenia
Hyperglycaemia
Risk factors for neonatal candidemia
Extreme prem ( < 28 weeks) ELBW Immature immune system impaired barrier function of skin and mucosa Indwelling catheter Broad spectrum antibiotics Parenteral nutrition H2 blockers Steriods Hyperglycaema Abdo surgery Multiple site candida colonisation
Features of the rash in scarlet fever
Fine punctuate erythema SPARING AREA AROUND THE MOUTH
What Is the rash in scarlet fever which is sparing around the mouth called?
Circumoral pallor
What is another name for slap cheek?
Erythema infectiosum
What causes slap cheek?
Parovirus B19
Presentation of slap cheek
Lethargy Fever Headache Rash - "slapped cheek rash" - spreading to proximal arms and extensor surfaces
Presentation of mumps
Fever
Malaise
Muscular pain
Parotitis unilateral then turning bilateral in 70%
Presentation of parotitis
Earache
Pain on eating
Presentation of measles
Prodrome - irritable - conjunctivits - fever Koplik spots Rash
What are kolpik spots?
White spots on buccal mucosa
Rash in measles
Starts behind ears
Then whole body
Discrete maculopapular rash becoming blotchy and confluent
When is GBS a problem in patients?
Pregnant women (can spread to baby)
Young babies
Elderly
What does GBS stand for?
Group B strep
Where is GBS found in normal healthy people?
Vagina
Rectum
If in GP practice and suspect meningitis, what can be given?
IM BenPen
What can be given in strep pneumoniae meningitis?
Dexamethasone
What triggers the rash once its gone in slap cheek?
Warm bath
Sunlight
Heat
Fever
Complication of slap cheek in pregnant women
Hydrops fetalis
What is scarlet fever characterised by?
Sandpaper rash
What causes roseola infantum?
Herpes virus 6
Incubation of roseola infantum
5 - 15 days
What age of child is affected by roseola infantum?
6 months - 2 years
Presentation of roseola infantum
High fever lasting a few days. Followed by
Maculopapular rash
Nagayama spots; popular enanthem on the uvula and soft palate
Febrile convulsions in 10 - 15%
Diarrhoea and cough are common
Other possible consequences of roseola infantum
Aseptic meningitis
Hepatitis
Is school exclusion needed for roseola infantum?
No
What is the most common cause of anal itching in children?
Threadworms
Treatment of meningitis in children < 3 months
IV cefoxamine
AND
IV amoxicillin to cover listeria
What infection has the prodrome of fever, irritability and conjunctivitis?
Measles
