Scarlet fever

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Scarlet fever

• Introduction
• 1 A kind of acute infectious
• disease of respiratory tract
• 2 Group A ß-hemolytic
• streptococcus
• 3 Main clinical manifestation
• acute fever
• pharyngitis
• diffuse and red exanthem(rash)

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• desquamation and hyperpigmentation
• 23weeks later
• rheumatic fever
• glomerulonephritis
• arthritis

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• Etiology
• Group A ß-hemolytic streptococci
• 1 Morphology and structure
• Gram-positive spherical cocci
• Diameter 0.61.0 µm
• Capsule() flagellum and spore(-)
• Streptococcus groups AH KU on the basis of
  C-carbohydrate within the cell wall
• Group A more than 80 immunologically
  distinct types that are based on differences in
  the M protein.
• 2 Pathogenecity
• M protein resists phagocytosis

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• the major virulence factor
• to neutrophils and platelets
• Capsule resist phagocytosis
• Lipoteichoic acid another
• virulence
  factor
• bind to
  fibronectin on
• the surface of
• epithelial
  cells
• Pyrogenic toxin produce rash, fever

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• resist phagocytosis,
• promote Schwartzman
• reaction
• Streptokinase
• Streptodornase
• Streptolysin O S WBC, RBC platelet
• Hyaluronidase hyaluronic acid

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• Epidemiology
• 1 Source of infection
• Patients in scarlet fever or
• pharyngitis
• Carriers with streptococci in nasal and
• pharyngeal
• 2 Route of transmission
• droplet, skin lesion, food, milk
• and water and so on.
• 3 Susceptibility of population
• Anti-bacterium immunity anti-M
• Anti-pyrogenic toxin immunity

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• 4 The feature of epidemiology
• season, age, endemic area, variation of
  this disease

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• Pathogenesis
• 1 Suppurative change
• Pathogen----epithelial cells----diffusion in
  local tissue
• LTA
  hyaluronidase
• M protein
  streptokinase, streptodornase
• capsule
  streptolysin
• -----------suppurative change
• pharyngitis,
  tonsillitis
• peritonsillar
  abscess
• 
  retropharyngeal abscess
• otitis media,
  sinusitis
• 
  lymphangitic-----lymphadenitis
• 
  bacteremia(sepsis, osteomyelitis,
• 
  pneumonia)

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• 2 Toxic change
• pyrogenic exotoxin (erythrogenic exotoxin)
• fever
• scarlatina rash
• other toxic symptoms
• 3 Allergic reactive change
• 23weeks later,
• Heart-------rheumatic fever
• Kidney-----glomerulonephritis
• joint---------arthritis
• reason 1)similar antigen----crossed immune
• 
  reaction
• 2)immune complex

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• Clinical manifestation
• Incubation period 23days(17days)
• Character of clinical manifestation
• Fever Pharyngitis scarlatina rash
• 1 Fever
• 1) feature persistent,
• fever rash
• 2) tem. 3940?
• 3) accompanied symptoms
• headache, weakness, poor appetite
• 4) course 1 week

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• 2 Pharyngitis
• symptom
• sign
• 3 Rash
• 1) fever rash 24 hours
• 2) initial position ear , neck, upper chest
• 3) feature diffuse papular(punctate or finely)
• miliary sudamina (not so
  many)
• circumoral pallor
• strawberry tongue
• red strawberry tongue
• Pastia lines(antecubital
  fossate)
• desquamation and
  hyperpigmentation

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• Type of clinical manifestation
• light type
• toxic type
• sepsis type
• surgery type
• obstetrics type

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• Laboratory examination
• 1 peripheral picture WBC, neutrophil 80
• 2 Urine allergic reaction protein RBC,
• WBC, cylindruria
• 3 bacteriology test Immunological
• fluorescence
• assay(IFA)
• bacteria
  culture

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• Complication
• 23 weeks later
• rheumatic fever
• glomerulonephritis
• arthritis

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• Diagnosis
• 1 clinical data fever, pharyngitis, rash
• 2 laboratory test peripheral picture,
• Urine
• Bacteriology test
• Dick test ( pyrogenic
  test)
• 3 epidemiology data

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• Differential diagnosis
• 1 staphylococcus infection
• 2 drug rash
• 3 Virus rash
• measles, rubella etc.

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• Treatment
• 1 penicillin adult 80?U/ time, bid 57days.
• child20?U/(kg d), 10days
• 800?U/d(adult)
• 2 erythromycin

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• Prevention
• 1 Isolation patients in scarlet
• fever
• 2 protection