Scarlet fever has reached a 49-year peak. Here, antibiotics are the saviour, not the villain

The number of scarlet fever cases in 2015 were higher than in any other year since 1967, according to a statement by Public Health England — and the infection rate is predicted to rise further.

There were 17,586 diagnoses last year, and 600 new cases are being recorded every week. The infectious disease, for which there is no vaccine, mostly affects children under the age of ten. Symptoms include fever, headaches, a sore throat and a rough red rash covering the arms, chest or back.

Public Health England (PHE) said more cases were expected as scarlet fever’s peak season is March and April. The body is urging GPs to be aware of the disease when diagnosing patients.

The data suggests that the number of cases began to rise sharply three years ago. In 2013 there were only 4,462 reported cases, but by 2014 this had increased to 15,625.

PHE said there was no clear reason for the dramatic spike in scarlet fever cases, saying that it ‘may reflect the long-term natural cycles in disease incidence seen in many types of infection’.

According to Public Health England (PHE) there were 1,265 cases of scarlet fever in the first six weeks of 2016 compared to 762 for the same period last year.

Instant analysis
Scarlet fever is a bacterial illness and the typical characteristics are a fine red rash, sore throat, fever, sickness and a headache. However, these features can be mimicked by a variety of viral illness affecting children. There is also probably a spectrum of scarlet fever-type illnesses, with the milder versions often being termed scarlatina by older GPs.

In this context it is very important to appreciate that the reports of scarlet fever cases received by PHE are not derived from laboratory data but from a clinical diagnosis by a doctor.

Doctors have a statutory duty to notify suspected cases of certain infectious diseases such as scarlet fever. This can be any doctor from one with a single year of experience — who might never have seen a case of scarlet fever before — to another who has been in practice for over 30 years.

Many older GPs are aware of the difficulties in making a clinical diagnosis of scarlet fever and some might look for more specific features such as a bright red tongue, which has the surface appearance of a strawberry, combined with pallor around the mouth.

It has been known since the 19th century that there is a five- or six-year cycle in scarlet fever cases and, moreover, that more cases are likely at this time of year. But, although the increase reported by PHE may reflect a real increase, it might also reflect enhanced awareness among the public and younger doctors (possibly linked to the publicity given to the condition over the last couple of years by PHE!), misdiagnoses and enhanced notification rates.

The bottom line is that the reason for being aware of scarlet fever is that it responds well to antibiotics. The irony here, of course, is that another division of PHE is actively seeking to vilify doctors who prescribe antibiotics for sore throats.