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

desquamation and hyperpigmentation desquamation and hyperpigmentation ******* ******* 2~3weeks later 2~3weeks later rheumatic fever rheumatic fever glomerulonephritis glomerulonephritis arthritis arthritis

Etiology Etiology Group A β-hemolytic streptococci Group A β-hemolytic streptococci 1 Morphology and structure 1 Morphology and structure Gram-positive spherical cocci Gram-positive spherical cocci Diameter: 0.6~1.0 μm Diameter: 0.6~1.0 μm Capsule(+) flagellum and spore(-) Capsule(+) flagellum and spore(-) Streptococcus groups: A~H & K~U 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. Group A : more than 80 immunologically distinct types that are based on differences in the M protein. 2 Pathogenecity 2 Pathogenecity M protein: resists phagocytosis M protein: resists phagocytosis

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

resist phagocytosis, resist phagocytosis, promote Schwartzman promote Schwartzman reaction reaction StreptokinaseStreptodornase Streptolysin O & S: WBC, RBC & platelet Hyaluronidase: hyaluronic acid

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

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

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

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

Clinical manifestation Clinical manifestation Incubation period 2~3days(1~7days) Incubation period 2~3days(1~7days) Character of clinical manifestation: Character of clinical manifestation: Fever Pharyngitis scarlatina rash Fever Pharyngitis scarlatina rash 1 Fever 1 Fever 1) feature: persistent, 1) feature: persistent, fever & rash* fever & rash* 2) tem. : 39~40 ℃ 2) tem. : 39~40 ℃ 3) accompanied symptoms: 3) accompanied symptoms: headache, weakness, poor appetite headache, weakness, poor appetite 4) course: 1 week 4) course: 1 week

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

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

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

Complication 2~3 weeks later 2~3 weeks later rheumatic fever rheumatic fever glomerulonephritis glomerulonephritis arthritis arthritis

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

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

Treatment 1 penicillin adult: 80 万 U/ time, bid 5~7days. 1 penicillin adult: 80 万 U/ time, bid 5~7days. child:20 万 U/(kg d), 10days child:20 万 U/(kg d), 10days 800 万 U/d(adult) 800 万 U/d(adult) 2 erythromycin 2 erythromycin

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