After the rash, the skin may scale or even peel off for a long time.
Diagnosis
Streptococcus pyogenes can be shown in a pharyngeal swab (or sample from another infectious focus) by culture or rapid antigen test.
For differential diagnosis of eruptive skin rash, see the article Exanthem (eruptive skin rash)Exanthem (Eruptive Skin Rash)
Treatment
Rarely requires hospital treatment.
Primarily phenoxymethylpenicillin for 10 days
All the causative streptococci are sensitive to penicillin.
For adults, penicillin V, 1 million IU 3 times daily
For children, penicillin V mixture, 66 mg/kg/day (for children over 6 years of age treated with tablets 50 000-100 000 IU/kg/day) divided into 3 doses (must not exceed the adult dose)
For patients with penicillin allergy
For adults and children over 6 years, weight > 30 kg: cephalexin 500 mg 3 times daily
For children ≤ 6 years, weight < 30 kg: cephalexin 25-50 mg/kg/day
For patients with penicillin and cephalosporin allergy, clindamycin or azithromycin can be used.
Infectivity ends 24 h after beginning antimicrobial treatment (the isolation period).
There is no vaccine available.
Criteria for referral
Patients with clearly impaired general condition should be referred to hospital.
Scarlet fever may sometimes cause an invasive septic disease leading even to shock.
References
Herdman MT, Cordery R, Karo B et al. Clinical management and impact of scarlet fever in the modern era: findings from a cross-sectional study of cases in London, 2018-2019. BMJ Open 2021;11(12):e057772. [PubMed]
Lamagni T, Guy R, Chand M et al. Resurgence of scarlet fever in England, 2014-16: a population-based surveillance study. Lancet Infect Dis 2018;18(2):180-187. [PubMed]