Scarlet fever: the disease in the UK
The statutory requirement to report certain infectious diseases started from 1891 in London and in the rest of England and Wales in 1899. At that time it was the responsibility of the landlord or head of the household to report diseases such as cholera, diphtheria, smallpox and typhoid to the local “proper officer”.
Sarah Marshall, is a pharmacist and freelance journalist from Banchory, Aberdeenshire
Mike Wyndham Picture Library
Strawberry tongue: a common symptom of scarlet fever
Panel 1: Notifiable diseases
Now notification is required under the Public Health (Infectious Diseases) Act 1988 and the Public Health (Control of Diseases) Act 1988 , with the aim of rapid detection of possible outbreaks and epidemics. Registered medical practitioners who suspect a notifiable infection must report it to the proper officer of the local authority, who then informs the Health Protection Agency (HPA) Centre for Infections.
There are now about 30 notifiable diseases, including acute poliomyelitis, cholera, diphtheria, and meningitis as well as infections such as measles, malaria and tetanus. A full list is given in chapter 5 of the British National Formulary.
Reports are collated and published regularly on the HPA website. In Scotland statutory notifications data are collected by Health Protection Scotland (formerly the Scottish Centre of Infection and Environmental Health), and in Northern Ireland by the Communicable Disease Surveillance Centre.
In the 19th century, scarlet fever was a feared disease, causing devastating pandemics with high mortality. Older members of the community may recall young children with scarlet fever being kept in isolation hospitals for weeks, their toys and bed linen burned for fear of spreading the infection, and glass screens kept between them and visiting parents. For reasons that are not clearly understood, but which may be related to general improvements in health and living conditions of the population or a change in the organism itself, or both, scarlet fever is no longer as virulent in the West as was once the case. As a consequence, many developed countries are removing scarlet fever from their notifiable diseases registers1 but, at present, it remains a notifiable disease in the UK (see Panel 1).
Scarlet fever is a bacterial infection caused by Streptococcus pyogenes, which is classified as Group A streptococcus (GAS; also known as Group A beta-haemolytic streptococcus). The “A” refers to the presence of a surface antigen. Figures suggest that up to 40 per cent of the population are asymptomatic carriers, with low infectivity and little risk of developing complications.
GAS is the most common cause of a bacterial sore throat (“strep throat”). It can also cause impetigo. More serious presentations of GAS infection include bacteraemia, necrotising fasciitis (a severe infection involving death of areas of soft tissue below the skin), streptococcal toxic shock syndrome (rapidly progressive symptoms with low blood pressure and multiple organ failure) and scarlet fever.
Mild streptococcal throat infections are often seen by GPs. Serious GAS infections, however, are infrequent. In 2004, there were some 2,200 cases of scarlet fever notified in England and Wales, 190 cases in Scotland and 228 cases recorded in Northern Ireland. A decade ago there were more than 6,000 cases annually in England and Wales. How much of the declining incidence can be attributed to under-reporting is unclear.2
The GAS infections that cause scarlet fever are spread by coughing, sneezing or breathing out of bacteria during the subclinical and acute phases of the illness. The incubation period is short, normally between two and four days, and the incidence of infection is highest in children aged four to eight years. The risk of transmission is moderate within families, and low elsewhere except for rare outbreaks, such as the one that occurred in Wiltshire in January and February of this year, where some 50 cases were reported.3 Although scarlet fever occurs most often as a result of a streptococcal sore throat it can follow infection of other sites, such as wounds and burns, particularly in tropical countries.
Typically the first symptoms of scarlet fever are a sore throat and fever (usually above 38.5C), with a bright red (“scarlet”) rash developing within a day or so. This rash is due to the production of an erythrogenic toxin by the bacteria, which passes into the bloodstream via the infected throat. Some children appear more susceptible to this toxin than others, developing scarlet fever while others may present with just a streptococcal throat infection. The rash starts as small spots usually on the neck and upper chest, and spreads to the rest of the body. It blanches when pressed and has a “sandpaper” feel to it. The cheeks may become flushed, although the mouth area remains pale. The tongue may become coated with a white fur with red papillae poking through (described as a “strawberry tongue”) which, after a few days, becomes red with prominent papillae (a so-called “raspberry tongue”).
Other common symptoms include headaches, chills, vomiting, lack of appetite, and feeling generally unwell. On examination, the tonsils and back of the throat may appear red, swollen and dotted with whitish or yellowish pus. As the rash fades some of the skin, mainly on the hands and feet, may peel.
Diagnosis is based on the symptoms listed above, while being aware that viral infections and Kawasaki disease may present similarly. The latter is an uncommon condition that mimics infectious disease but as yet no causal organism has been identified. The Health Protection Agency (HPA) uses the following clinical and microbiological criteria to diagnose and categorise scarlet fever cases:1,3
· Confirmed cases Clinical symptoms consistent with streptococcal sore throat (a sore red throat, fever, headache, and swollen lymph nodes in the neck and under the jaw) and at least one characteristic sign of scarlet fever (a skin rash, strawberry tongue, flushing of cheeks with a pale area around the mouth and peeling of the skin in convalescence) and a positive laboratory isolate of GAS from a throat swab
· Probable case Clinical symptoms consistent with streptococcal sore throat and at least one characteristic scarlet fever sign and no throat swab performed or throat swab performed without significant growth
· Possible case Clinical symptoms consistent with a streptococcal sore throat and no characteristic signs of scarlet fever and no throat swab performed or a throat swab performed but failed to produce significant growth
Some clinicians use the term “scarlatina” to describe the milder clinical illness which occurs in the West today, with its less frequent complications. Others regard scarlet fever and scarlatina as synonymous.
Treatment for scarlet fever is as for a streptococcal sore throat, using phenoxymethylpenicillin or erythromycin for those allergic to penicillin. The duration and frequency of the antibiotic regimen is a matter for debate. Most studies regard oral penicillin V given six-hourly for 10 days as the gold standard of treatment for a sore throat where GAS has been detected. It also has the advantages of cheapness and tolerability.4 However, many of these studies were conducted in the 1950s and 1960s when scarlet fever was more virulent.
Trials carried out more recently have looked at shorter courses, lower frequencies of administration and other antibiotics, such as cephalosporins. The choice of antibiotic and the duration of treatment for GAS pharyngitis are the subjects of much needed forthcoming Cochrane reviews.
Paracetamol or ibuprofen can be used for symptomatic relief of scarlet fever. The patient should be kept cool, rested and hydrated with plenty of fluid. Most patients make a full and uneventful recovery. The HPA advises that children infected with scarlet fever should be kept off school and away from others for five days after the start of antibiotics, but advice on this is variable.
Complications of scarlet fever in the West are rare but are still a problem in emerging economies. They include localised spread of the infection, to cause ear infections, throat abscesses and sinusitis, and more distant spread causing pneumonia, meningitis, osteomyelitis or septic arthritis. Late complications sometimes develop two to three weeks after the infection has gone, and include acute rheumatic fever and glomerulonephritis. Treatment with antibiotics is thought to reduce the risk of complications — especially in countries where they occur frequently — but evidence for antibiotic use in Britain (where complications are rare) is inconclusive.5
Rheumatic fever used to be a common childhood disease until the middle of the 20th century but is now rare in the West. It is thought to be due to a hypersensitivity reaction caused by host antibodies to streptococcus cross reacting with host tissue in the heart. The symptoms include fever, arthritis moving from joint to joint, reddish circular patches on the skin, chorea, small painless nodules on the knuckles, elbows and knees, and carditis.
Endocarditis leads to valvular heart disease. Treatment includes penicillin to eradicate any organisms still present, high doses of non-steroidal anti-inflammatory drugs to relieve arthritis, appropriate treatment of heart failure and chorea, and bed rest. Antibiotic prophylaxis is necessary to prevent GAS bacteraemia, which can result in further valve damage.
Glomerulonephritis refers to any of a group of kidney diseases involving inflammation of the glomeruli. When the condition is caused by streptococcal infection, patients typically present with acute nephritic syndrome two or more weeks post-infection. Inflammation of the glomeruli may lead to blood, protein and red blood cell casts being present in the urine and peripheral oedema, although in some patients symptoms may be variable or even absent. Almost all children will recover within several weeks without treatment (other than antibiotics for the infection).
Scarlet fever is now a mild disease in developed countries and serious complications are more common in emerging economies. Treatment of scarlet fever in the West may need to take account of this decreased virulence.
With scarlet fever being under-reported it is difficult to get a true picture of its prevalence in the UK. It is possible that in the future it will be removed from the notifiable diseases register in line with other developed countries. A personal case study of scarlet fever is presented in Panel 2.
Panel 2: Case study
It was 4.30 in the morning. There was the sound of padding feet and the small voice of my five-year-old daughter in my ear: “I’ve got a headache and I’m hot and I can’t sleep.” She was, indeed, running a high temperature and had a sore throat. Concerned about another bout of tonsillitis, I dosed her with paracetamol and later I gave her some ibuprofen too because her fever was not responding. I noted that she was developing a red rash on her neck and trunk and thought it odd — she does not normally develop a viral rash until later on in an infection and it usually looks different.
The ibuprofen and paracetamol were able to control her temperature for only a couple of hours at a time, even at maximum doses, and she said they burnt her tongue. Lukewarm baths helped lower the fever. The following day she was clearly unwell. I took her temperature, 40.4C, despite all the medication. I hastily pressed a glass to her florid rash, heaving a huge sigh of relief when it blanched.
The GP diagnosed a streptococcal infection and once I explained that my daughter cannot usually keep phenoxymethylpenicillin or erythromycin down, he prescribed a seven-day course of amoxicillin, having dismissed the likelihood of glandular fever. It was a couple of hours after I got home that the penny dropped. I rang the GP back: “Has she got scarlet fever,” I asked, incredulously. “Yes, but it is not the disease it once was,” was the reply. Within a few hours of starting the antibiotic my daughter became much brighter. Her cheeks reddened, but her mouth remained pale, her tongue was red with spots. Being the daughter of a pharmacist she was woken at 10pm every night to make sure her doses of antibiotic were evenly spaced and she finished the course.
Over the following weeks my daughter had several episodes of a high fever, sore throat and headache. Eight weeks after the initial diagnosis my daughter had a fourth bout of high fever, sore throat, headache, swollen glands and, for the first time since the original episode, a red rash. My GP suspected a recurrence of the streptococcal infection. He prescribed a 14-day course of co-amoxiclav and throat swabs subsequently confirmed the presence of Streptococcus pyogenes. Her urine was checked for protein and the results excluded nephritis. To my relief she responded quickly to the antibiotic.
I am glad to be living in the 21st century and not the 19th.
Health Protection Agency
www.hpa.org.uk gives information on Group A streptococcal infections and notifiable diseases.
www.patient.co.uk gives patient information on scarlet fever, glomerulonephritis, rheumatic fever and mitral valve disease.
www.prodigy.nhs.uk gives guidance on acute sore throats and information on scarlet fever and Kawasaki disease.
1. Feeney KT, Dowse GK, Keil AD, Mackay C, McLellan D. Epidemiological features and control of an outbreak of scarlet fever in a Perth primary school. Communicable Diseases Intelligence 2005;29:386–90.
2.Sen D, Osbourne K. General practitioners’ knowledge of notifiable, reportable and prescribed diseases. BMJ 1995;310:1299.
3. Health Protection Agency. Scarlet fever outbreak in two nurseries in south west England. CDR Weekly 2006;16:1–2.
4. Scottish Intercollegiate Guidelines Network. Management of sore throat and indications for tonsillectomy: a national clinical guideline. 1999. Report No.34.
5. Del Mar CB, Glasziou PP, Spinks AB. Antibiotics for sore throat. The Cochrane Database of Systematic Reviews 2004; issue 2.
Citation: The Pharmaceutical Journal URI: 10001690
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