What is scarlet fever?
Scarlet fever is contagious when caused by a certain Group A strep bacteria strain. Scarlet fever can be transmitted via person-to-person contact and by coming in contact with contaminated objects. Treatment includes antibiotics. Scarlet fever symptoms include a red rash, fever, a red, sore throat, strawberry tongue, and others.
Scarlet fever (also termed scarlatina) is an illness characterized by a bright red rash that can cover most of the body and is caused by a toxin secreted by group A streptococci, a type of gram-positive coccus-shaped (round) bacteria.
Scarlet fever usually occurs in individuals that have had a strep throat infection or occasionally in those who have had streptococcal skin infection. The majority of people who get scarlet fever are between about 5-12 years of age. (It rarely occurs in babies under 2 years of age.)
Scarlet Fever Incubation Period
The incubation period for scarlet fever has a fairly wide range from about 12 hours to seven days. Individuals are contagious during this first subclinical or incubation period and during the acute illness. The primary strep infection is the contagious aspect.
How do you get scarlet fever?
Scarlet fever may be contagious if a person becomes infected with a group A streptococcal bacterial strain that produces the scarlet fever toxin. However, not all people who get group A streptococcal infections develop scarlet fever; only a small percentage of these patients go on to develop scarlet fever.
Consequently, scarlet fever spread is the secondary result of the way most group A streptococcal infections are spread — by direct person-to-person contact (kissing, touching mucus membranes, for example) and by indirect methods such as contaminated eating utensils, cups, and other objects used by infected individuals. However, not all individuals who get group A streptococcal infections will develop scarlet fever.
What are the symptoms of scarlet fever?
Individuals with scarlet fever usually have some or most of the following symptoms and signs:
- Red rash with a sandpaper feel when touched
- Fever above 101 F
- Red, sore throat
- A "strawberry-like" appearance of the tongue
- Headache, body aches
- Nausea and/or vomiting
- Enlarged lymph nodes
- Some individuals may have whitish coating on the tongue and/or back of the throat
The red rash may develop later than other symptoms (up to about seven days later). The physician can give a clinical diagnosis from the patient's history, physical exam, and possibly a rapid strep test; in some individuals, a throat culture may be done to determine if group A strep is the infecting bacteria.
Is Scarlet Fever Contagious?
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What is the treatment for scarlet fever?
- Scarlet fever can be treated with antibiotics because once the streptococci bacteria are debilitated or killed, they stop producing toxins and the rash will slowly fade away.
- A medical caregiver can help diagnose scarlet fever by doing a simple strep test or, if indicated, can culture the throat to confirm a group A streptococcal infection.
- Individuals with scarlet fever need to be treated quickly with antibiotics to reduce the chance of developing long-term health problems such as rheumatic fever, kidney disease, ear infections, and other types of infections.
When should I call a doctor about scarlet fever?
- An individual should see a medical caregiver if they have had a recent infection of strep throat and then develop the symptoms of scarlet fever (especially a reddish rash on the body).
- It's important to have a physician evaluate the patient to be sure that appropriate diagnosis and treatment (antibiotics) take place quickly to avoid or reduce the chances of any of the complications of scarlet fever such as organ impairment (of the kidneys, heart, joints, for example).
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Medically Reviewed on 10/5/2021
"Scarlet Fever: A Group A Streptococcal Infection." Centers for Disease Control and Prevention. Jan. 19, 2016.