Scarlet Fever Passmed Flashcards
What is Scarlet Fever and its common age of incidence?
Scarlet fever is a reaction to erythrogenic toxins produced by Group A haemolytic streptococci, typically Streptococcus pyogenes. It is most common in children aged 2-6 years, with the peak incidence at 4 years.
How is Scarlet Fever transmitted?
Scarlet fever spreads via the respiratory route through inhaling or ingesting respiratory droplets, or direct contact with nose and throat discharges during sneezing and coughing.
What is the incubation period and typical presentation of Scarlet Fever?
Scarlet fever has an incubation period of 2-4 days. Typical presentation includes fever (lasts 24-48 hours), malaise, headache, nausea/vomiting, sore throat, ‘strawberry’ tongue, a fine punctate erythema rash starting on the torso, sparing palms and soles, with a ‘sandpaper’ texture, and later desquamation around fingers and toes.
How is Scarlet Fever diagnosed?
Diagnosis of Scarlet Fever usually involves a throat swab, but antibiotic treatment should be commenced immediately, rather than waiting for results.
How is Scarlet Fever managed?
Management of Scarlet Fever involves oral penicillin V for 10 days. If allergic to penicillin, azithromycin is given. Children can return to school 24 hours after starting antibiotics. It is a notifiable disease.
What are the common and severe complications of Scarlet Fever?
Common complications of Scarlet Fever include otitis media. Severe complications can include rheumatic fever (typically 20 days post-infection), acute glomerulonephritis (typically 10 days post-infection), and rare invasive complications like bacteraemia, meningitis, and necrotizing fasciitis.
Which one of the following is responsible for causing scarlet fever?
Group A haemolytic streptococci
Staphylococcus aureus
Human herpesvirus type 6
Parvovirus B19
Coxsackie A16
The correct answer is Group A haemolytic streptococci. Scarlet fever, also known as scarlatina, is primarily caused by group A beta-haemolytic streptococci (GABHS), specifically the bacterium Streptococcus pyogenes. This organism produces an erythrogenic toxin that leads to the characteristic rash of scarlet fever. The disease mainly affects children and presents with a sore throat, fever, strawberry tongue and a fine sandpaper-like rash.
Staphylococcus aureus is incorrect because while it can cause skin infections and other illnesses like food poisoning, toxic shock syndrome, and septicaemia, it does not cause scarlet fever. However, it’s worth noting that S. aureus can co-infect with GABHS and complicate the clinical picture.
Human herpesvirus type 6 is also not responsible for causing scarlet fever. Instead, this virus causes roseola infantum (also known as sixth disease), which is characterised by a high fever followed by a pink-red raised or flat rash on the trunk which may spread to the limbs but rarely involves the face.
Parvovirus B19, on the other hand, causes erythema infectiosum (also known as fifth disease) or ‘slapped cheek’ syndrome in children. It presents with a bright red rash on both cheeks giving them a slapped appearance. It does not cause scarlet fever.
Finally, Coxsackie A16 virus is associated with hand-foot-and-mouth disease (HFMD). HFMD typically starts with a mild nonspecific febrile illness followed by oral ulcers and maculopapular or vesicular rash on hands and feet. It does not cause scarlet fever
A 5-year-old girl is brought in by her mother. Mum reports she started to feel unwell two days ago, complaining of a sore throat and headache. Overnight, she developed a temperature and vomited once. This morning she has broken out in a rash all over her body, this has spread from her chest where it started. On examination, she has a temperature of 38.5ºC, heart rate 130 beats per minute, she looks flushed and has an erythematous rash over her body which feels like sandpaper and blanches with pressure. There are palpable cervical lymph nodes when you examine her neck and her tongue has a white coating over it. What is the most likely diagnosis?
Parvovirus B19
Varicella
Measles
Adenovirus
Scarlet fever
This child has Scarlet fever. There is a typical incubation period of 2 to 4 days and typically presents with fever, tonsillitis, malaise and rash. Two specific features of Scarlet fever are ‘strawberry tongue’ which is when the tongue is covered with a white coat through which red papillae may be seen. Later, the white covering disappears, leaving the tongue with a beefy red appearance. The typical rash in this condition starts on the torso before spreading all over the body- it has a typical rough ‘sandpaper’ like texture. Varicella causes a typical vesicular rash. In measles, the prodromal symptoms are typically coryza, conjunctivitis and high fever before the rash appears- usually starting on the head or neck. Parvovirus B19 causes ‘slapped cheek syndrome’ with bright red rash seen on both cheeks, Adenoviruses can cause lots of different infections such as respiratory infections, gastroenteritis or conjunctivitis. There is no specific associated rash.
A 4-year-old boy presents to his GP with a new-onset fever, red tongue, and widespread rash that appeared first on his torso but has not spread to the soles of his feet. His mother describes the rash as a rough ‘sandpaper’ texture. Oral antibiotics are prescribed for the following ten days.
The patient regularly attends his nursery on weekdays however, his mother is concerned and questions when he may return.
When is the most appropriate time for the patient to return to school?
24 hours after commencing antibiotics
4 days from the onset of the rash
48 hours after commencing antibiotics
5 days from the onset of the rash
Until symptoms have settled for 48 hours
24 hours after commencing antibiotics
A child with scarlet fever can return to school 24 hours after commencing antibiotics
The correct answer is to return to school 24 hours after commencing antibiotics as these are the guidelines in place for a new diagnosis of scarlet fever.
4 days from the onset of the rash is the incorrect answer as this would be appropriate for those with measles.
48 hours after commencing antibiotics is the incorrect answer as this would be most appropriate for children with whooping cough.
5 days from the onset of the rash is most appropriate for a rubella infection and not scarlet fever.
Until symptoms have settled for 48 hours would be inappropriate to advise in this case as this would be recommended for children with diarrhoea and vomiting.
A 4-year-old girl is brought into the emergency department with a sore throat and fever. She has had 4 episodes of vomiting today and is off her food. She was delivered at 32+6 weeks via Caesarean section due to a massive maternal haemorrhage. She is reaching her developmental milestones. She has no regular medications or allergies. On examination, she has an erythematous tongue and throat with no purulent tonsilar discharge. There is a coarse erythematous rash over the torso, arms, and legs which is confluent in the flexures.
Considering the likely diagnosis, what is the most appropriate management?
Flucloxacillin
Penicillin V
Supportive therapy (paracetamol and encourage fluid intake)
Topical hydrocortisone 1% cream
Topical ketoconazole
Penicillin V
Scarlet fever classically presents with a sore throat, fever, headache, bright red tongue and a coarse, red rash
This patient is presenting with symptoms and signs consistent with scarlet fever. She has a sore throat, fever, and vomiting alongside a ‘strawberry’ tongue (bright red and bumpy) and coarse ‘sandpaper’ rash. She should be managed with 10 days of oral penicillin V and can return to school 24 hours after starting the antibiotics.
Flucloxacillin is the management for cellulitis and other skin infections which are likely caused by Staphylococcal or Streptococcal species. Cellulitis presents with fever and an area of erythematous, oedematous skin usually with a skin break site for a point of entry for the bacteria. The erythema should be marked out with a pen around its borders to assess for any tracking. Flucloxacillin is not indicated in the management of scarlet fever.
Supportive therapy (paracetamol and encourage fluid intake) would be supportive if the patient was considered to have a simple viral upper respiratory tract infection, however, this patient is presenting with a rash and upper respiratory signs consistent with scarlet fever. The rash should guide the student away from considering this to be a simple viral infection. Children may develop viral exanthematous rashes, however, these are typically splotchy and red rather than like sandpaper.
Topical hydrocortisone 1% cream is used in the management of rashes, such as pityriasis rosea. This condition presents with a bumpy, red rash of scaly patches and is typically in children who are older (from 10 years onwards). This condition does not usually lead to systemic features of vomiting or fever. Most patients will have a resolution of symptoms without any medication in 2 weeks.
Topical ketoconazole is used in the management of athlete’s foot and ringworm, it is used against fungal infections. As scarlet fever is caused by Group A Streptococcus this is an inappropriate option.
