Infectious Disease 2.0

Question 1

Give me some deets on streptococcal / staphylococcal:

Answer 1

Strep

• Gram-positivecocci
• Penicillin
• Noresistanceissues!

Staph

• Gram-positive cocci
• Flucloxacillin (= synthetic penicillin resistant to β- lactamases
• Resistance big issue! • MRSA
• carriers

Question 2

What is scarlatina?

Answer 2

Scarlet fever - strep A infection

Question 3

Scarlatina

Cause?

Affects which children?

Complications?

Rx?

Answer 3

• Cause: Group A β-hemolytic streptococci Children < 2 years of age relatively protected
• > 10 years of age natural protection in 80%
• Virulence factors: M-protein, exotoxins
• Complications:
  
  • Erysipelas, Cellulitis, Impetigo - Streptococcal toxic shock
  • Rheumatic fever 0.3-3%
  • Glomerulonephritis
• Penicillin 10 days

Question 4

Scarlatina

SSx?

Answer 4

• Very red sore throat.
• Fever
• Lymphadenopathy
• Whitish coating on the tonsils and throat.
• Headache or body aches.
• Nausea, vomiting, or stomach pain.
• Difficulty swallowing.

Question 5

What organisms can cause impetigo?

Answer 5

Staph aureus and strep pyogenes

Question 6

What is SSSS?

Answer 6

Staphylococcal scalded skin syndrome

Question 7

SSSS

Caused by?

SSx?

Answer 7

• Exotoxins of S. aureus,
• Mostly kids < 5 yrs (particularly in newborns)
  
  • Fever
  • widespread redness
  • fluid-filled blisters
  • rupture easily
  • especially in the skin folds

Question 8

What is Kawasaki disease?

Answer 8

Mucocutaneous lymph node syndrome, is a disease in which blood vessels throughout the body become inflamed. Self-limited vasculitis of medium-sized arteries

Question 9

SSx of Kawasaki disease?

Answer 9

• Fever for at least 5 days and four of the five
  
  • bilateral conjunctival injection
  • changes of the mucous membranes
  • cervical lymphadenopathy
  • polymorphous rash
  • changes of the extremities
• peripheral oedema
• peripheral erythema
• periungual desquamation

Question 10

Rx for Kawasaki disease?

Answer 10

To prevent complications like vasculitis coronary arteries:

• Immunoglobulins
• Aspirin
• Other immunosuppressive agents

Question 11

How can we differentiate between different vesicular rashes and fever?

Answer 11

Question 12

What are the most common varicella zoster viruses?

Answer 12

• primary infection (Varicella, Chickenpox)
• recurrent infection (Zoster)

Question 13

SSx of Chickenpox?

Answer 13

• mild malaise and fever (kids are not sick!)
• exanthema: papules → vesicles → pustules → crustae → (scarring) new laesions during 5-7 days
• itching
• Lasts for 10-21 days

Question 14

Complications of chickenpox?

Prevention of chickenpox?

Answer 14

• secondary strep/staph infections skin (10-15%)
• meningoencephalitis, cerebellitis, arthritis
• vaccination (active/passive)

Question 15

What are more severe versions of varicella zoster virus?

Answer 15

• Fatal varicella (2 : 100.000)
• <1 year of age (8:100.000)
• Signs:
  
  • Fever
  • new lesions >day10
  • Inflammed lesions

Question 16

What are the most common herpes simplex virus infections?

Answer 16

• Stomatitis (primary infection)
• Recurrent cold sores

Question 17

Herpes simplex

Complications?

Rx?

Answer 17

• (kerato) conjunctivitis
• encephalitis
• systemic neonatal infections
• They are normally self limiting
• (or) acylovir

Question 18

What happens if a neonate gets a herpes simplex virus?

Answer 18

• Day 4 -21 of life
• 70-80% disseminated/CNS infections • Sepsis
  
  • Meningoencephalitis
  • Hepatitis (jaundice, bleeding)
• 20-30% skin/eye/mouth (SEM) disease
• 2-3/100,000
• High mortality
  
  • Without acyclovir > 50% • With acyclovir 20-30%

Question 19

Hand foot and mouth disease

Cause?

Incubation period?

When?

SSx?

Answer 19

• Enteroviruses; Coxsackie A16 and enterovirus 71
  
  • Incubation period: • 3-6 days
• Children <10 jaar
• Summer and early autumn
• Clinical:
  
  • Exanthema en enanthema
  • Painful laesions
  • Recovery in 5 to 10 day

Question 20

Dx for vesicular rashes?

Answer 20

• Clinical diagnosis
• Smear of vesicle (ulcer base)
  
  • Tzanck test: no differentiation HSV/VZV
• PCR (fluids, CSF, blood)
• Serology (past infections only)

Question 21

Summary (probs useful just to know this…!)

Answer 21

• Staphylococcus aureus and Streptococcus pyogenes cause comparable diseases, ranging from mild to severe, but choice of antibiotics is organism specific.
  
  • Scarlet fever is exclusively caused by S. pyogenes
• Vesicular rashes in childhood are caused by varicella zoster, herpes simplex and enteroviruses in children and in general do not need specific therapy.
  
  • Those viruses can cause severe neonatal infections
• Kawasaki disease needs to be differentiated from S. pyogenes infections.