FFinalistSouthampton · 2027
Child health
AKT · Child health/Infection & rash

Scarlet fever

Group A Strep (Strep pyogenes) — erythrogenic toxin

Overview

A notifiable toxin-mediated illness from group A streptococcus: sore throat and fever with a fine SANDPAPER rash, strawberry tongue and circumoral pallor. Treated with penicillin to prevent complications.

Recognise

  • Fever, sore throat, headache
  • Fine "SANDPAPER" erythematous rash (spares the palms/soles), flushed cheeks with CIRCUMORAL PALLOR
  • Strawberry tongue; rash in skin folds (Pastia lines); later desquamation

Red flags

  • Complications: rheumatic fever, post-strep glomerulonephritis, invasive GAS/toxic shock

Differentials & how to tell them apart

Kawasaki diseasefever ≥5 days, conjunctivitis, cracked lips, extremity changes — does NOT respond to antibiotics
MeaslesKoplik spots, coryza/conjunctivitis, cephalocaudal maculopapular rash
Viral exanthemno sandpaper texture/strawberry tongue, no GAS
Slapped cheek (parvovirus)lacy rash, lower fever

Investigations

Clinical; throat swab/rapid antigen for GAS. NOTIFIABLE — inform UKHSA.

Management

Phenoxymethylpenicillin (penicillin V) for 10 days

  1. 1Notify. Phenoxymethylpenicillin (penicillin V) for 10 days.Gate: Penicillin allergy → azithromycin 5 days or clarithromycin 10 days (erythromycin in pregnancy)
  2. 2Exclude from school until 24 hours after starting antibiotics. Antipyretics/fluids.
Phenoxymethylpenicillin (penicillin V) — first-line, 10 days
Azithromycin/clarithromycin — penicillin allergy

Key points

Penicillin prevents rheumatic fever and reduces post-strep complications. Notifiable. School exclusion 24h after antibiotics.

Monitor & prognosis

Response in 24–48h; watch for complications.

Excellent with antibiotics.

Source: NICE CKS Scarlet fever (2025); UKHSA