Scarlet fever
Scarlet fever is an infection caused by toxin producing strains of Streptococcus pyogenes (also known as group A streptococcus, or GAS). It was associated with high levels of deaths and complications when epidemics were common in the 18th and 19th centuries in Europe and the USA.
Scarlet fever or ‘scarlatina’ is the name given to a disease caused by an infective Group A Streptococcal (GAS) bacteria. For many years, scarlet fever was very rare. But, once of a sudden, there has been a recent increase in the number of cases worldwide.
In this article:
- What Is scarlet fever?
- Symptoms
- When to see a doctor
- Causes
- Is scarlet fever contagious?
- Risk Factors
- Complications
- Prevention
- Diagnosis
- Throat swab
- References
What Is scarlet fever?
Scarlet fever is an infection caused by toxin producing strains of Streptococcus pyogenes (also known as group A streptococcus, or GAS). It was associated with high levels of deaths and complications when epidemics were common in the 18th and 19th centuries in Europe and the USA.
Scarlet fever or ‘scarlatina’ is the name given to a disease caused by an infective Group A Streptococcal (GAS) bacteria. For many years, scarlet fever was very rare. But, once of a sudden, there has been a recent increase in the number of cases worldwide.
For example, in Asia, Vietnam reported over 23,000 cases and mainland China reported over 100,000 cases in 2009. Smaller outbreaks have also occurred in USA and Canada. In the U.K., Public Health England has reported a total of 12,906 cases between September 2015 and April 2016, the largest outbreak in the U.K. since 1969.
For the majority of people treated promptly, the outcome is excellent. Recovery is usually complete in 3-6 days, but the skin symptoms may take 14-21 days to subside.
In a few people, the infection can recur. In the era of antibiotics, death from scarlet fever is less than 1%. The complications of scarlet fever are glomerulonephritis, rheumatic fever, sinusitis, and other infections. Complications, though, are rare.
Symptoms
Scarlet fever usually presents as;
1.Tonsillitis and exudative pharyngitis:
- Red large tonsils that get covered with whitish spots or film
- Sore throat
- Fever
- Difficulty swallowing, too much saliva
2. A spreading maculo-papular rash starting from the trunk (torso) – it is frequently called sandpaper rash due to it being rough on touch
3. “Strawberry” tongue is a very characteristic sign – a tongue becomes bright red and all small papillae become bigger in size.
4. In 7-10 days the rash starts disappearing, but skin peeling occurs, especially on the palms and soles.
Although scarlet fever can affect any age, it is most common in children aged between 3 and 8 years. The incidence of scarlet fever among males is typically higher than females. Surges in scarlet fever incidence have been repeatedly reported during the winter and summer.
When to see a doctor
Usually this is a mild disease that goes away on its own in 7-10 days. You should always seek medical help if:
- Fever is too high and cannot be brought down by OTC meds
- There are signs of toxemia – inability to eat and drink, severe body aches and severe headache
- Neck pain with intractable headache (it can be a life-threatening meningococcal disease)
- There are also breathing problems and cough – these symptoms are common in COVID-19, measles and rubella
Causes
Streptococcus pyogenes (group A Streptococcus, GAS) is arguably the most virulent of all clinically important streptococci. It can cause a variety of diseases such as:
- severe invasive diseases, such as necrotizing fasciitis
- strep throat
- toxic shock syndrome,
- immunopathological complications such as acute rheumatic fever.
Is scarlet fever contagious?
Yes – it is contagious. Scarlet fever is transmitted by passing a bacteria from sick to a healthy person. It can be also transmitted from a healthy person who is a carrier (strep bacteria can live in tonsils without causing symptoms).
Risk Factors
Historically, epidemics of scarlet fever often occurred every five to six years, possibly due to the accumulation of type-specific herd immunity among the susceptible population in the community.
People with low immune function are most likely susceptible, so it is important to do everything to keep immune system healthy:
- get sunlight exposure to boost vit D levels
- eat healthy organic food
- do not take unnecessary antibiotics
- exercise
- wash hands frequently and avoid crowded places during epidemics
Complications
The complications fall into two categories, suppurative and non-suppurative. Typically, suppurative complications result from a worsening, an extension, or a spread of the original area of infection.
As an example, a bacterial pharyngitis can spread to the ear, causing otitis media; the sinuses, causing a sinusitis; and then to the meninges, causing bacterial meningitis. Non-suppurative complications generally are mediated through an immune response after the original infection resolves. Rheumatic fever, a disease affecting the heart valves, is a complication of GAS infection that results in long-term morbidity.
Suppurative complications (with pus):
- Peritonsillar/pharyngeal abscess
- Otitis media
- Sinusitis
- Necrotizing fasciitis
- Streptococcal bacteremia
- Meningitis or brain abscess
- Jugular vein septic thrombophlebitis
Non-Suppurative complications (no pus):
- Acute rheumatic fever
- Poststreptococcal reactive arthritis
- Streptococcal toxic shock syndrome
- Acute glomerulonephritis
- Pediatric autoimmune neuropsychiatric disorder associated with group A streptococci
Complications are very rare nowadays.
Prevention
Scarlet fever is a disease of childhood due to ease of transmission in the classrooms and nurseries. The key to prevention is family education on hygiene, such as handwashing, not sharing cups and utensils in the cafeteria, prompt notification of schools and daycare if the child is sick with scarlatina.
The pharmacist should emphasize to the patient that full recovery occurs when antibiotic compliance is complete.
In addition, the nurse should educate the patient on hand and personal hygiene to prevent transmission of the bacteria to others. Patients should be educated about the skin infection and the general exfoliation, and when to seek medical assistance. The skin symptoms are frequently relieved with the use of emollients and oral antihistamines.
Diagnosis
Scarlet fever is mainly a clinical diagnosis. Many of the presenting symptoms associated with scarlet fever are similar to those caused by other common infections in children and adults, such as:
- Mono (Epstein-Barr virus), adenovirus or other respiratory viruses
- Measles and rubella. Atypical measles and rubella can affect people who were vaccinated
- COVID-19. A PCR or antigen tests can tell you if you have this virus
- Chicken pox (herpes zoster)
- Hand-foot-and-mouth disease (Coxsackie)
- Allergic rash. Atopic dermatitis and contact dermatitis present with similar rashes, but there are no other infectious symptoms present
- Food allergy may cause large tonsils and geographic tongue, as well as fine itchy rash on the body
Throat swab
Because scarlet fever presents with such a wide variation in severity, it is difficult to diagnose in its early stages. Individual signs and symptoms are not powerful enough to discriminate GABHS pharyngitis from other types of sore throat. It can be confirmed with the throat culture for β-haemolytic streptococcal (GABHS). COVID-19 rapid antigen test or PCR may help to rule that disease out.
A prolonged duration of fever (>38.5 °C) and the degree of tachycardia (fast heart rate) coupled with the spreading bilateral trunk rash, results in a confident Scarlatina diagnosis.
Centor score for predicting group A β-haemolytic streptococcal (GABHS) pharyngitis in adults (> 14 years of age) presenting with sore throat symptoms can be used to make a correct diagnosis.
References
Managing scarlet fever. [No authors listed]Drug Ther Bull. 2017 Sep;55(9):102. doi: 10.1136/dtb.2017.8.0529.PMID: 28882851 Review.
Comparison of Centor and McIsaac scores in primary care: a meta-analysis over multiple thresholds. Willis BH, Coomar D, Baragilly M.Br J Gen Pract. 2020 Mar 26;70(693):e245-e254. doi: 10.3399/bjgp20X708833. Print 2020 Apr.PMID: 32152041 Free PMC article.
Accuracy and precision of the signs and symptoms of streptococcal pharyngitis in children: a systematic review. Shaikh N, Swaminathan N, Hooper EG.J Pediatr. 2012 Mar;160(3):487-493.e3. doi: 10.1016/j.jpeds.2011.09.011. Epub 2011 Nov 1.PMID: 22048053 Review.
Scarlet fever: a guide for general practitioners. Basetti S, Hodgson J, Rawson TM, Majeed A.London J Prim Care (Abingdon). 2017 Aug 11;9(5):77-79. doi: 10.1080/17571472.2017.1365677. eCollection 2017 Sep.PMID: 29081840 Free PMC article. Review.