Infection 1 Flashcards
Why do children present with different presentations in infections?
Developing immune system
What is systemic inflammatory response syndrome? (SIRS)
Fever or hypothermia
Tachycardia
Tachypnoea
Leucocytosis
What is sepsis?
Bacteraemic infection + SIRS
What happens to organs in the body as a result of sepsis?
Dysfunction/failure
How is severe sepsis defined?
Sepsis + 2 or more of; (Respiratory failure Renal failure Neurological faliure Haematological failure Liver failure) ARDS Septic shock - CVS failure
Are boys or girls more likely to get sepsis?
Boys
Are younger or older cihldren more likely to get sepsis?
Younger
What are common causative organisms of sepsis in neonates?
Group B strep
E coli
Listeria monocytogenes
What are common causative organisms in children?
Strep pneumoniae
Meningococci
Group A strep
Staph aureus
What is the pathophysiology of sepsis?
Lipopolysaccharide and other bacterial toixns activate inate immune cells and endothelium secretion
Mass activation of cytokines and compement
Microvascular occlusion and vascular instability
Leads to fever, coagulopathy, vasodilation, and capillary leak leading to sepsis and multiorgan failure
What are symptoms of sepsis?
Fever or hypothermia Cold hands/feet, mottled Prolonged cap refill Chills/rigors Limb pain Vomiting and/or diarrhoea Muscle weakness Muscle/joint aches Skin rash Diminished urine output
What are 6 criteria of paediatric sepsis recognition?
Temp <36 or >38 Inappropriate tachycardia Poor cap refill/mottled Altered mental state Inappropriate tacypnoea Hypotension
What supportive treatment is done for sepsis?
A - Airway
B - Breathing/oxygen
C - Circulation - fluids
DEFG - Don’t ever forget glucose
What is causative treatment for sepsis?
Antibiotics with broad spectrum and good CSF penetration
What blood investigations are done for sepsis?
FBC - leucocytosis, thrombocytopenia
CRP - elevated
Coagulation factors - DIC
U&Es/LFTs - Renal and hepatic dysfunction
Blood gas - Metabolic acidosis, raised lactate
Glucose - hypo
Blood cultures
What non-blood investigations are done for sepsis?
CSF cell count and culture - raised WCC and PCR
CSF protein and glucose - raised protein, lowered glucose
Urine culture
Skin biopsy and culture
Imaging
What pathogens cause meningitis in nenonates?
Group B strep
E coli
Listeria monocytogenes - same as sepsis
What pathogens cause meningitis in children?
Strep pneumoniae
Neisseria meningitidis - meningococcus
Haemophilus influenzae
What are symptoms of meningitis in children?
Niuchal rigidity - neck stiffness Headaches Photophobia Diminished consciousness Focal neurological abnormalities Seizures
What are symptoms of meningitis in neonates?
Lethargy
Irritability
Bulging fontanelle
Seizures
How do you assess for meningococcal rash?
Tumbler test
What is a meningococcal rash called?
Petichial rash
What are complications of pneumococcal meningitis?
Brian damage
Hearing loss
Hydrocephalus
Where do meningococci come from in meningococcal meningitis?
Nasopharynx
How long after meningococcal infection of the nasopharynx do sepsis and meningitis occur?
Septic shock=<12 hours
Meningitis=18-36 hours
What toxin do meningococci produce?
Lipooligosaccharide
How are streptococci treated?
Penicillin
How are staphylococci treated?
Flucloxacillin
Why is flucloxacillin used over penicillin in staphylococci?
It is resistant to beta lactamases
What bacteria causes Scarlet fever?
Strep A
What is the progression of Scarlet fever?
Contact Incubation - 2-4 days Malaise, fever, pharyngitis Rash Squamation of hands and feet Strawberry tongue
What is the most common age for strep A infection?
2-10 years
What are complications of strep A infection?
Scarlet fever
Poststreptococcal glomerulonephritis
Rheumatic fever
Toxic shock syndrome
Where is staph aureus carried as a commensal organism?
Nasal passage
Perineum
Axillae
What diseases are caused by staph aureus?
Impetigo Cellulitis Infected eczema Ulceration Staph scalded syndrome Toxic shock syndrome
What are features of impetigo?
Highly contagious
Golden sores and blisters, no systemic symptoms
What are features of staph scalded skin syndrome?
Mostly in kids under 5
Fever
Widespread redness
Fluid filled blisters, especially in skin folds
What are features of toxic shock syndrome?
Systemically unwell Widespread redness Desquamation Multi-organ involvement Can be rapidly fatal
What is Kawasaki disease?
Self-limited vasculitis of medium sized arteries
What are features of Kawasaki disease?
Fever for 5 days plus: Bilateral conjunctival infection Cracked lips/strawberry tongue Cervical lymphadenopathy >1.5cm Polymorphous rash Changes of the extremities
How is Kawasaki disease diagnosed?
Exclude differentials - no diagnostic test
How is kawasaki disease treated?
Immunoglobulins
Aspirin
Steroids
Other immunosuppressive agents
What is the goal of Kawasaki disease treatment?
Prevent complications
What infections cause erythematosus maculopapulous rash?
Measles Rubella Enterovirus Cytomegalovirus EBV
What infections cause vesiculobullous rash?
Varicella zoster virus
Herpes simplex virus
Enterovirus
What infections cause petechial and purpuric rash?
Rubella (congenital)
Cytomegalovirus (congenital)
Enterovirus
What are features of varicella zoster virus infetion?
Mild malaise and fever
Itchy
Skin lesions progressive - papules ->vesicles ->Pustules ->crustae for 5-7 days
How is varicella zoster virus treated?
Conservatively
If severely unwell or immunosuppressed - aciclovir
What are warning signs of fatal varicella?
High fever
New lesions for more than 10 days
Inflamed lesions
General malaise
Where do HSV 1 and HSV 2 act?
HSV1 - oral
HSV 2 - genital
What are features of HSV infection?
Stomatitis
Recurrent cold sores
What are complications of HSV?
Keratoconjunctivitis
Encephalitis
Systemic neonatal infections
Immunocompromised children
How is HSV treated?
Aciclovir
What infectious agents cause hand-foot-mouth disease?
Enteroviruses
What is the most common time of year for hand-foot-mouth disease?
Summer and early autumn
What are clinical features of hand-foot-mouth disease?
Exanthema
Painful lesions
Recovery in 5-10 days
What are examples of physical barriers to infection?
Skin Mucous membranes Mechanical defences Chemical defences Microbiome
What are the SPUR F warning signs for immunodeficiencies?
Serious
Persitent
Unusual Recurrent
Family history
What investigations are done into suspected immunodeficiency?
FBC Immunoglobulins HIV test Functional antibodies Lymphocyte subsets Complement NBT
How do antibody deficiencies generally present?
Defective B cell function - present with recurrent bacterial infections ie pneumonia
How do cellular immunodeficiencies present?
Impaired or absent T cell function - present with unusual or opportunistic infections, recurrent/severe viral infections
How do innate immune disorders present?
Defects in phagocyte function - presents with sepsis, abscess, fungal infections
How are most paediatric HIV cases transmitted?
Vertically - from mother during utero
How is HIV prevented in children at risk?
Mothers antenatally screened
Mothers receive retroviral therapy and babies receive prophylaxis postnatally until further testing
Mothers advised not to breastfeed
