Severe Infections Flashcards
What is a super antigen?
Antigens that results in excessive activation of the immune system
What is the antigen that provokes staphylococcal toxic shock syndrome?
TSST-1 antigen (toxic shock syndrome toxin)
What are features of TSS?
Extreme fever > 39.0
Septic shock
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)
How do you treat TSS?
Remove source of antigen
Organ support
What is a positive kernig’s sign and what does it suggest?
Step 1. The patient is positioned in supine with hip and knee flexed to 90 degrees
Step 2. The knee is then slowly extended by the examiner (Repeat on both legs)
Step 3. Resistance or pain and the inability to extend the patient’s knee beyond 135 degrees, because of pain, bilaterally indicates a positive Kernig’s sign
Meningitis
How is meningitis empirically treated if < 3 months?
Cefotaxime + Amoxicillin
How is meningitis empirically treated if 3 months - 50 years?
Cefotaxime
How is meningitis empirically treated if > 50 years?
Cefotaxime + Amoxicillin
How is meningococcal meningitis treated?
Intravenous benzylpenicillin or cefotaxime (or ceftriaxone)
What is the indication for steroids in meningitis?
septic shock
meningococcal septicaemia
immunocompromised
meningitis following surgery
Who should be contact traced in meningitis?
- close contacts of patients affected with meningococcal meningitis.
- exposed to respiratory secretion, regardless of the closeness of contact
- exposed to a patient with confirmed bacterial meningitis should be given prophylactic antibiotics if they have close contact within the 7 days before onset
How should contact traced individuals be managed for meningitis?
Oral ciprofloxacin
or
Oral Rifampicin
plus:
meningococcal vaccination should be offered to close contacts when serotype results are available, including booster doses to those who had the vaccine in infancy
What causes viral meningitis?
non-polio enteroviruses e.g. coxsackie virus, echovirus
mumps
herpes simplex virus (HSV), cytomegalovirus (CMV), herpes zoster viruses
HIV
measles
What are the features of viral meningitis?
Headache
Nuchal rigidity
Photophobia (often milder than the photophobia experienced by a patient with bacterial meningitis)
Confusion
Fevers
If you are waiting on CSF result and suspect mengitis, even viral, how should it be treated?
IV ceftiraxone
IV acyclovir
While awaiting result
What are the features of a bacterial meningitis csf?
Appearance: Cloudy
Glucose: Low (less than half of plasma)
Protein: High (>1g/l)
White cells: 10-5000 (polymorphic)
What are the features of a viral meningitis csf?
Appearance: Cloudy / clear
Glucose: 60-80% of plasma
Protein: Normal / raised
White cells: 15-1000 Lymphocytes
What are the features of a tuberculosis meningitis csf?
Appearance: Cloudy / fibrin web
Glucose: Low (less than half of plasma)
Protein: High (>1g/l)
White cells: 30- 3000Lymphocytes
What would make you think a CSF fungus?
Low lymphocytes <30
What are typical causes of cellulitis?
Streptococcus pyogenes
Staph aureus
How should cellulitis be treated?
Flucloxacillin first line
Pen allergic: Doxycycline
Pregnant or penicillin allergic: Clarithromycin / erythromycin
Severe cellulitis:
co-amoxiclav, cefuroxime, clindamycin or ceftriaxone.
What causes caveatting lung lesions?
Staph aureus (PVL staph)
Klebsiella
TB
squamous cell carcinoma - most common oncology cause
How is listeria meningitis treated? How is general listeria infection treated?
General: Amoxillin / ampicillin
Meningitis: IV Amoxicillin and Gentamicin
What are the features of a listeria infection
diarrhoea, flu-like illness
pneumonia
ataxia and seizures
meningoencephalitis
Who are 20 times more likely to get a listeria infection?
Pregnant women
What are the complications of listeria in pregnancy?
fetal/neonatal infection can occur both transplacentally and vertically during child birth
complications include miscarriage, premature labour, stillbirth and chorioamnionitis
What is a risk factor for having anthrax?
Being a butcher
What is Lemierre’s syndrome and what causes it?
Lemierre’s syndrome is an infectious thrombophlebitis of the internal jugular vein.
Fusobacterium necrophorum
What is the pathophysiology of lemierre’s syndrome?
a bacterial sore throat caused by Fusobacterium necrophorum leading to a peritonsillar abscess. A combination of spread of the infection laterally from the abscess and compression lead to thrombosis of the IJV.
Complications of lemierre’s ?
Septic pulmonary emboli
Pneumonia + Alcoholic + Cavitation ?
Klebsiella
Pneumonia + Prior Flu?
Staph pneumonia
Pneumonia + Chicken Pox Rash?
Varicella
Pneumoniae Pneumonia + Hemolytic Anemia?
Mycoplasma
Pneumonia + Hyponatraemia + Travel History?
Legionella
Pneumonia + Fleeting opacities?
Cryptogenic Pneumonia
Pneumonia + Fits/LOC?
Aspiration pneumonia
Pneumonia + HSV oral lesion?
Strep Pneumonia
Pneumonia + parrot?
Chamlydia pittasci
Pneumonia + farm animals?
Q fever - coxiella
Pneumonia + HIV?
think pcp but if straight forward case strep pneumonia is still most common
Pneumonia + Cystic fibrosis?
Consider pseudomonas/Burkholderia
Pneumonia + COPD or exac ?
Haemophillus
Commonest cause of CAP?
strep pneumonia
What is the most likely cause of sepsis from a central line?
Staph epidermis - Cause of central line infections and infective endocarditis
What should be given alongside antibiotics in bacterial menginitis?
Dexamethasone
Reduced neurological sequelae
What is the treatment of tetanus?
Metronidazole
Treatment of meningitis and penicillin allergic?
Chloramphenicol
What is the cause of necrotising fascitis ?
type 1 is caused by mixed anaerobes and aerobes (often occurs post-surgery in diabetics). This is the most common type
type 2 is caused by Streptococcus pyogenes
Risk factors for necrotising fascitis?
skin factors: recent trauma, burns or soft tissue infections
diabetes mellitus
the most common preexisting medical condition
particularly if the patient is treated with SGLT-2 inhibitors
intravenous drug use
immunosuppression
Features of necrotising fascitis?
acute onset
pain, swelling, erythema at the affected site
often presents as rapidly worsening cellulitis with pain out of keeping with physical features
extremely tender over infected tissue with hypoaesthesia to light touch
skin necrosis and crepitus/gas gangrene are late signs
fever and tachycardia may be absent or occur late in the presentation
