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Sarah Marshall, is a pharmacist and
freelance journalist from Banchory, Aberdeenshire
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Mike Wyndham Picture Library
Strawberry tongue: a common symptom of scarlet fever |
Panel 1: Notifiable diseases
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”.
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
Transmission
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. Symptoms
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
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
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
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). Conclusions
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. |
Useful websites
Health Protection Agency
www.hpa.org.uk gives information on Group
A streptococcal infections and notifiable diseases.
Patientplus
www.patient.co.uk gives patient information on scarlet fever, glomerulonephritis, rheumatic
fever and mitral valve disease.
Prodigy
www.prodigy.nhs.uk gives guidance
on acute sore throats and information on scarlet fever and Kawasaki
disease.
References
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. |
The
Pharmaceutical Journal