Infectious emergencies Flashcards
Who principally gets Staphylococcal scalded skin syndrome (SSSS)?
Most common in neonates and infants, but may occur up to 6yo
Can occur in adults but usually only in those with significant illness or medical comorbidities
What are the risk factors for adult SSSS?
AKI/CKD
Poorly controlled diabetes
Immunosuppression
What are the typical features of SSSS?
Fever/malaise/poor feeding
Macular erythema and pain usually in the skin folds»_space; flaccid bullae, superficial desquamation appear usually with a wrinkled appearance»_space; perioral and facial skin crusting»_space; erosions of the skin with minimal trauma»_space; can cover most of the body
This condition has a postive Nikolsy sign
What is the treatment for SSSS?
Supportive care as for burns (wound dressings, IV fluids) patients +/- transfer to a burns centre
Antistaphylococcal antibiotics such as Flucloxacillin, Vancomycin if suspected MRSA and Clindamycin if strong penicllin allergy
Clindamycin is hypothesised to reduce ribosomal production of the SSSS toxin, but evidence for this is lacking and it is not first line therapy
Case reports of improvement with IVIG and plasmapharesis have been shown but this is not typical treatment
What are the risk factors for Toxic Shock Syndrome (TSS)
Menstrual tampon use (50% cases)
- high absorbency types, longer duration of use, leaving tampon in for extended periods
Surgical
- Post partum, surgeries with packing left in (ie nasal)
Staph Infection
- Any primary Staph aureus infection ie burns infection, osteomyelitis, mastitis, retained foreign body etc
What is the pathogenesis of TSS?
Caused by S. aureus strains producing exotoxins (TSST-1, enterotoxin A-H etc) or GAS producing M Protein exotoxin
These exotoxins in susceptible individuals acts as superantigens causing massive widespread T cell activation through binding to MHC class II molecule.
Most people develop an antibody to TSST-1 but people who fail to do this or children between the ages of 6 months to 2 years (waning passive, insufficient active immunity) are at high risk
What are the clinical manifestations of TSS?
- High fevers, malaisea, generalised aches and pains
- Severe hypotension
- Diffuse red macular rash resembling sunburn, mucosal hyperaemia +/- haemorrhage or superficial ulcerations
Desquamation may occur but usually weeks into the disease - Multi organ failure
What are the criteria for TSS diagnosis post event?
Clinical
- Fever
- Rash
- Rash desquamates 1-2 weeks later
- Hypotension
- Multisystem involvement (>3)
Lab
- Cultures negative for other causes
- Serologic tests negative for other causes
How are Staph TSS and Strep TSS differentiated?
Strep TSS usually starts with significant pain at the site of initial infection +/- skin findings
Strep TSS often also involves necrotising fasciitis/myonecrosis
What is the treatment of TSS?
Surgical debridement (Strep) or removal of foreign body (staph) if applicable
Supportive care with fluids and pressors
Empiric therapy with Vancomycin, Clindamycin and a broad spectrum betalactam or carbapenem (Taz, Cefepime, meropenem etc)
Clindamycin (and linezolid) are hypothesised to help due to their suppression of bacterial protein synthesis and thus suppression of toxin formation
IVIG has been used in patients refractory to normal treatment but is not normal practice
What are the risk factors for Necrotizing fasciitis?
Diabetes (number 1)
Older age
Obesity
Alcoholism/Cirrhosis
Peripheral vascular disease
Immunocompromised (HIV, chemo etc)
Trauma to the site (Major or minor)
Recent surgery (including neonatal circumcision)
Mucosal breach (ie haemorrhoids, fissures, episiotomy)
Obstetric complications and gynaecological procedures
SGLT-2 inhibitors for Fourniers
What is the acute vascular complication associated with Ludwigs Angina and cervicofacial nec fasc?
Lemierre syndrome
A septic thrombophlebitis of the internal and external jugular veins
Can lead to thromboembolism, intracerebral venous stasis and raised ICP
What are the empiric antibiotics for Nec Fasc?
- Broad spectrum beta lactam ie Tazocin 4.5gm or Meropenem 1gm
- An agent effective against MRSA ie Vancomycin 15mg/kg
- Clindamycin 600-900mg for its bacteriostatic anti toxin producing effects
How is Nec Fasc diagnosed?
Nec Fasc can only be diagnosed with a surgical biopsy
What is Fourniers Gangrene?
Nec Fasc of the Perineum and surrounding areas
Typically caused by a mucosal breach and polymicrobial urinary and/or enteric pathogens
Most common in older men
What are the basics of Anthrax?
Bacillus anthracis
Cutaneous
- Most common form, usually associated with skin abrasions when working in dirt or with animals
- Localised papules become bullae and when burst form an eschar
- An eschar with extensive surrounding oedema is pathognomonic for anthrax
- Systemic symptoms are rare but herald high mortality, overall mortality 4%
GI
- Results from consumption of undercooked meat with animals infected with anthrax
- Haemorrhagic gastroenteritis and GI ulceration/perforation
- Massive intestinal lymphadenopathy
- Mortality 60-70% without treatment but 4% with treatement
Respiratory
- Uncommon, usually terrorism
- Can have an incubation period of 1-2 days, but up to 100 days
- Causes necrotizing pneumonia with severe thoracic lymhpadenopathy that may cause obstruction
- Mortality is 92%
Treatment
- Ciprofloxacin 30mg/kg
- Meropenem 2gm
- Linezolid 600mg
- Anthrax immunoglobulin
What is the difference between viral and bacterial meningitis on LP?
- 10-40mg/dl = 0.6-2.2mmol of glucose
- Bacterial has PMN/Neutrophil predominance, viral has monocyte/lymphocyte predominance
- bacterial often has CSF lactate >3.5, highly suspicious if >3.5
