Incidence of Scarlet fever has increased in UK recently.

Scarlet fever – Summary

Scarlet fever is a notifiable infectious disease caused by a particular strain of the group A streptococcus bacterium (Streptococcus pyogenes).

The bacteria are spread when the person’s mouth, throat, or nose comes into contact with infected saliva or mucus (which may be present on cups, utensils, pencils, and surfaces), or by aerosol. Outbreaks in schools or other institutions sometimes occur.

Once the person has had scarlet fever, they are unlikely to contract it again (although they will still be susceptible to other forms of streptococcal infection).

Scarlet fever most commonly affects children of school age, peaking at 4 years of age[/color]

For most people scarlet fever is a mild, self-limiting illness. Clinical features of the infection, including the rash, usually resolve over about 1 week.

Complications of scarlet fever are rare. However:

Complications due to spread of the infection (e.g. otitis media and throat infection) tend to occur early in the infection.

Autoimmune complications such as rheumatic fever tend to occur later in the course of infection, particularly (but not exclusively) in untreated people.

Diagnosis of scarlet fever is usually made on the basis of characteristic clinical features alone. The first clinical features to develop are:

Sore throat.

Fever (typically greater than 38.5°C).

Headache, fatigue, nausea, and vomiting.

An alternative diagnoses (e.g. rubella, measles, parvovirus B19) should be considered if signs and symptoms are atypical, particularly in older children and adults.

Examination of a person with scarlet fever may reveal:

Strawberry tongue (see attached picture)

Swollen cervical lymph glands.

Flushed face, with marked paleness around the mouth.

Skin folds in the neck, axillae, groin, elbow, and knees that are deep red in colour.

Throat inflammation and the presence of red flat spots dotted over the hard and soft palate.

Management involves:

Prescribing a 10-day course of an oral antibiotic (penicillin or a macrolide if the person is allergic to penicillin)

Offering paracetamol or ibuprofen for symptom relief.

Encouraging the person to rest and drink adequate fluids.

Reassuring the person that scarlet fever is no longer a serious condition and that symptoms usually last for 1 week.

Advising the person to: stay away from school or work for 1 day after starting antibiotic treatment, wash their hands frequently (e.g. before preparing and eating food, and after sneezing), avoid sharing eating utensils and towels, dispose of handkerchiefs promptly, and avoid contact with anyone at particular risk of infection (e.g. people with valvular disease or who are immunocompromised).

The person should be advised to return for follow up only if symptoms worsen or have not improved after 7 days.

Specialist advice should be sought regarding admission for people who:

Have pre-existing valvular disease.

Are significantly immunocompromised (e.g. with clinically-apparent HIV infection).

Have a severe complication of scarlet fever (e.g. evidence of acute rheumatic fever or an invasive suppurative complication).

Have a severe form of scarlet fever, such as ‘septic’ or ‘toxic’ scarlet fever (characterized by high fever and marked systemic toxicity, possibly including arthritis and jaundice).

Dr G Mohan.