What are the signs and symptoms of scarlet fever?

Signs and Symptoms of Scarlet Fever

Scarlet fever presents with a characteristic constellation of signs and symptoms including sore throat, fever, and a distinctive sandpaper-like rash, along with specific oral manifestations such as strawberry tongue.

Cardinal Clinical Features

Initial Symptoms

• Fever: High-grade fever typically ranging from 101°F to 104°F (39°C to 40°C) 1
• Sore throat: Sudden onset, often severe with pain on swallowing 1
• Headache: Common accompanying symptom 1
• Systemic symptoms: Nausea, vomiting, and abdominal pain (especially in children) 1, 2

Characteristic Rash

• Appearance: Erythematous, sandpaper-like, papular skin rash 2, 3
• Timing: Usually appears within 1-2 days after onset of fever 1
• Distribution: Extensive involvement of trunk and extremities with accentuation in the perineal region 1
• Progression: Early desquamation may occur in the perineal region 1

Oral and Pharyngeal Findings

• Tonsillopharyngeal erythema with or without exudates 1
• Strawberry tongue: Erythematous tongue with prominent fungiform papillae 1, 3
• Oral mucosal changes: Erythema, dryness, fissuring, peeling, cracking, and bleeding of the lips 1
• Soft palate petechiae: Small hemorrhagic spots on the soft palate 1
• Beefy red, swollen uvula 1

Cervical Lymphadenopathy

• Tender, enlarged anterior cervical nodes 1

Disease Course and Progression

Timeline

• Incubation period: Typically 2-5 days after exposure
• Duration: Without treatment, fever typically persists for approximately 5-7 days 3
• Desquamation: Skin peeling, particularly of fingers and toes, may begin 1-3 weeks after initial symptoms 1

Age Distribution

• Most commonly affects children aged 5-15 years 2, 4
• Peak incidence in children 3-6 years of age 4

Diagnostic Considerations

Features Suggesting Group A Streptococcal (GAS) Origin

• Sudden onset of symptoms 1
• Absence of cough, coryza, hoarseness, or conjunctivitis (which suggest viral etiology) 1
• History of exposure to someone with documented GAS infection 1
• Seasonal pattern: More common in winter and early spring in temperate climates 1

Features Suggesting Viral Origin (Differential Diagnosis)

• Conjunctivitis
• Coryza (runny nose)
• Hoarseness
• Cough
• Diarrhea
• Characteristic viral exanthems or enanthems 1

Clinical Pitfalls and Caveats

• Transmission risk: Highly contagious through direct contact with saliva and nasal fluids 2
• Diagnostic challenges: May be confused with viral exanthems or other bacterial infections 2
• Treatment importance: Early diagnosis and treatment are crucial to prevent complications 3
• Complications: If untreated, can lead to serious sequelae including acute rheumatic fever, glomerulonephritis, bacteremia, pneumonia, endocarditis, and meningitis 2, 3

Management Considerations

• Microbiological confirmation (throat culture or rapid antigen detection test) is required for definitive diagnosis 1
• Antibiotic treatment should be initiated promptly to reduce duration, sequelae, and community spread 3
• Patients should be excluded from school/daycare for 24 hours after initiating antibiotic treatment, though this may not always prevent outbreaks 5
• Be aware of potential antibiotic resistance, particularly to erythromycin in some strains 6

Understanding these characteristic signs and symptoms allows for prompt recognition, diagnosis, and treatment of scarlet fever, reducing the risk of complications and further transmission.