//fpnotebook.com/
Scarlet Fever
Aka: Scarlet Fever, Second Exanthem of Childhood
- Pathophysiology
- Occurs in Group A beta-hemolytic streptococcal (GAS) infection (typically Streptococcal Pharyngitis)
- Some GAS strains produce streptococcal pyrogenic exotoxin
- Patients with Hypersensitivity to the toxin may develop a rash
- Epidemiology
- Occurs in 10% of Streptococcal Pharyngitis cases
- Symptoms
- Fever
- Peaks on Day 2
- Returns to normal on Day 5-7
- Chills
- Headache
- Vomiting
- Pharyngitis
- Signs
- Forehead and cheeks appear flushed
- Circumoral pallor and sparing of rash
- Pharyngitis
- Tonsils are hyperemic and edematous, with exudate
- Throat is inflamed and covered by a membrane
- Palatal Petechiae may be present
- Strawberry Tongue
- Fine Papules on Tongue surface
- Tongue dorsum may appear with a white exudate and projecting edematous papillae
- Sandpaper Rash
- Onset with 12-72 hours after fever
- Coalescing, blanching erythematous Macules (may appear Sunburn-like)
- Fine papular or punctate lesions
- Texture of coarse sandpaper
- Rash distribution
- Starts on upper trunk
- Rash distribution generalizes within 24 hours
- Rash may affect flexor creases (Pastia lines) in the axillae, antecubital, groin and neck
- Pastia lines due not typically blanche
- Rash spares the palms and soles
- However, Desquamation of palms and soles may occur
- Desquamation
- Follows rash fading after several weeks
- Desquamation of face, skin folds, hands and feet
- Desquamation may last up to 6 weeks
- Labs
- Streptococcal Rapid Antigen Test
- Throat Culture
- Used to confirm a negative rapid Antigen test
- Antistreptolysin O titer (ASO Titer)
- Confirms diagnosis, but not typically helpful in acute disease
- Differential Diagnosis
- Staphylococcal Scalded Skin Syndrome
- Kawasaki's Disease
- Also with Desquamation of palms and soles as well as strawberry Tongue
- Management
- See Group A Streptococcal Pharyngitis for management
- References
- Allmon (2015) Am Fam Physician 92(3): 211-6 [PubMed]