Scarlet fever is a bacterial illness that arises from a streptococcal infection, specifically the group A Streptococcus bacteria. This infection often follows strep throat, pharyngitis, or tonsillitis. Characterized by a distinct red rash, which feels like sandpaper, scarlet fever commonly affects children. The rash typically starts on the chest and spreads across the body. Accompanying symptoms include a high fever and a sore throat. If untreated, scarlet fever can lead to serious complications such as rheumatic fever. Prompt treatment with antibiotics is crucial to manage the infection and prevent further health issues.
7. Classification
Based on
Hemolysis
• 1. Alpha-hemolytic streptococci
(α-hemolysis):
partially lyse red blood cells
- Streptococcus pneumoniae
(pneumonia, meningitis, otitis media, and
sinusitis)
- Streptococcus viridans group
(Normally found in the mouth and upper
respiratory tract; important in causing dental
caries and subacute bacterial endocarditis)
8. Classification
Based on
Hemolysis
• 2. Beta-hemolytic streptococci (β-
hemolysis):
completely lyse red blood cells, producing
a clear zone around colonies
Group A Streptococcus (GAS or
Streptococcus pyogenes)(strep throat, scarlet
fever, rheumatic fever, and skin infections like impetigo and
cellulitis.)
- Group B Streptococcus (GBS or
Streptococcus agalactiae) (neonatal infections
such as sepsis, pneumonia, and meningitis. It can also cause
infections in pregnant women and the elderly.)
9. Classification
Based on
Hemolysis
• 3. Gamma-hemolytic
streptococci (γ-hemolysis or
non-hemolytic):
do not cause hemolysis and do not
change the appearance of the blood
agar.
Streptococcus bovis (Streptococcus
gallolyticus) (group, associated with colorectal
cancer and endocarditis.)
10. Classification Based on Lancefield
Grouping
• Based on the Carbohydrate composition of bacterial antigens
found on their cell walls. Not all species of streptococci are
grouped in this system, but it includes many clinically significant
types:
• Group A (GAS): Streptococcus pyogenes
• Group B (GBS): Streptococcus agalactiae
• Group C: Includes strains like Streptococcus equisimilis, which can cause pharyngitis and
occasionally skin infections.
• Group D: Includes Enterococcus spp., which are important in urinary tract infections and
hospital-acquired infections.
• Groups G and F: Less common; can cause pharyngitis and skin infections.
11. Group A beta-hemolytic streptococcus
(GAS), or Streptococcus pyogenes
• Highly virulent and contagious bacterium - ranging from mild
infections to severe, life-threatening illnesses in children
• Strep throat
• Impetigo
• Scarlet Fever
• Cellulitis & Erysipelas
• Invasive GAS
• Rheumatic fever
• PSGN (PIGN)
12. SCARLET FEVER
• Scarlet fever, also known as scarlatina, typically between the
ages of 5 and 15 years, though it can occur in younger children
and adults as well.
• Caused by Pyrogenic exotoxin (erythrogenic toxin) producing
GAS with pharyngitis & Characteristic rash
13. SCARLET FEVER – Clinical Features
Rash: The rash typically begins as small red blotches and develops
into fine pink-red bumps that feel like sandpaper. It usually starts on
the chest and abdomen and then spreads across the body.
"Strawberry Tongue": This term describes the appearance of the
tongue after the initial white coating peels off, leaving a red, swollen
tongue.
Fever and Chills: Temperatures of 101°F (38.3°C) or higher are
common.
14. SCARLET FEVER – Clinical Features
Sore Throat: Often severe and accompanied by difficulty swallowing.
Flushed Face: The face may appear flushed with a pale ring around
the mouth.
Peeling Skin: As the rash fades, the skin around the fingertips, toes,
and groin area may peel.
15. SCARLET FEVER –
Transmission
Scarlet fever is highly contagious and can
be transmitted through-
• respiratory droplets from coughing or
sneezing of an infected person.
• It can also spread through shared
contact with objects and surfaces.
16. SCARLET FEVER –
Diagnosis
Primarily based on physical
examination and the presence of
symptoms.
Confirmation is achieved via a
rapid antigen detection test
(RADT) or
Throat culture to detect group A
streptococcus.
17. SCARLET FEVER –
Treatment
Antibiotics: Culture directed,
Emperically Penicillin or Amoxicillin is
typically prescribed.
For penicillin-allergic individuals -
erythromycin or clindamycin may be
used.
Other supportive care –
antihistamines/PCM/topicals
18. SCARLET FEVER –
Treatment
Antibiotics: Culture directed,
Emperically - Penicillin or Amoxicillin is
typically prescribed.
Others – Azithromycin, Cephalosporins
For penicillin-allergic individuals -
erythromycin or clindamycin may be used.
Other supportive care –
antihistamines/PCM/topicals
19. SCARLET FEVER –
Complications (Suppurative,
bacteria mediated)
•Otitis Media and Sinusitis
•Pneumonia
•Toxic Shock Syndrome
•Necrotizing Fasciitis
•Peritonsillar Abscess
20. SCARLET FEVER – Complications (Immune
mediated)
1. Rheumatic Fever
Triggered by an autoimmune response to the M proteins on the
surface of S. pyogenes. These proteins can mimic molecules
found in human tissues - particularly those in the heart(carditis),
joints(arthritis), skin(erythema marginatum), and
brain(Sydenham’s Chorea).
2. Poststreptococcal Glomerulonephritis
Following infection, immune complexes (antigen-antibody
complexes) form and deposit in the glomeruli of the kidneys.
These complexes activate complement, which in turn attracts
inflammatory cells and mediates inflammation
21. SCARLET FEVER – PREVENTION OF
SPREAD
•Parental education about the contagious
nature of the disease.
•The child should stay home from school or
daycare until at least 24 hours after starting
antibiotics and until fever has resolved.
•NO VACCINE YET !!
22. Our patient
• Was started on AMOXYCLAV @ 40mg/kg/day orally
for 10 days
• Improved within 2 days
• Started skin peeling on day 6-7
• Otherwise improved
