Scarlet fever

Background

• Caused by Group A Strep

Clinical Features

Strawberry tongue.

Red "strawberry tongue" in a patient with scarlet fever.

Culture positive strep pharyngitis with typical tonsillar exudate

Characteristic red cheeks and rash of scarlet fever.

Scarlet fever rash.

• Prodrome of fever, sore throat, vomiting, abdominal pain followed by rash 1-2d later
• Rash
  • Enanthem (rash involving mucous membrane)
    • Tonsils/pharynx are red and covered with exudate
    • Tongue may have initial exudate followed by erythema ("strawberry tongue)
    • Soft palate have bright-red spots
  • Exanthem
    • Begins 1-2days after onset of illness
    • Starts on neck, axillae, groin, spreads to trunk and extremities
    • Red, finely punctate, sandpaper feel
    • Pastia lines: linear petechial eruptions in antecubital/axilla
    • Desquamation follows

Differential Diagnosis

Pediatric Rash

• Atopic dermatitis
• Bed bugs
• Contact dermatitis
• Drug rash
• Erythema infectiosum (Fifth disease)
• Hand-foot-and-mouth disease
• Henoch-schonlein purpura (HSP)
• Herpangina
• Herpes simplex virus (HSV)
• Infectious mononucleosis
• Meningitis
• Measles
• Molluscum contagiosum
• Roseola infantum
• Rubella (German measles)
• Scabies
• Scarlet fever
• Smallpox
• Varicella (Chickenpox)

Erythematous rash

• Positive Nikolsky’s sign
  • Febrile
    • Staphylococcal scalded skin syndrome (children)
    • Toxic epidermal necrolysis/SJS (adults)
  • Afebrile
    • Toxic epidermal necrolysis
• Negative Nikolsky’s sign
  • Febrile
    • Toxic shock syndrome
    • Kawasaki disease
    • Scarlet fever
    • DRESS syndrome
    • Cellulitis
    • Acute generalized exanthematous pustulosis
  • Afebrile
    • Alcohol intoxication
    • Anaphylaxis
    • Cellulitis
    • Dermatitis (multiple types)
    • Drug rash
    • Erysipelas
    • Erythema multiforme
    • Exfoliative erythroderma
    • Scombroid
    • Vancomycin infusion reaction

Evaluation

• Clinical diagnosis, based on history and physical exam

Management

• Treatment (to reduce rheumatic fever / nephritis)
  • Penicillin VK 50mg/kg BID x 10d OR Amoxicillin 50mg/kg/d in 2 divided doses or one time dose x10d
  • If allergic to penicillin → Azithromycin 10mg/kg on day 1, 5mg/g days 2-5

Disposition

• Discharge

See Also

• Pediatric Rash
• Acute rheumatic fever