Learn about the symptoms, treatment, and prevention of Scarlet Fever on Meri Sehat for reliable information and guidance.

Scarlet Fever

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Syed Intisar Hussain

Overview

Scarlet Fever is a contagious bacterial infection characterized by pharyngitis, fever, and a distinctive bright red rash. 
Previously called scarlatina, scarlet fever is common among children aged 5 to 15 years. The bacterial infection is characterized by a bright red &lsquo;sandpaper&rsquo; rash that covers the whole body.

&nbsp;

In 1553, the Sicilian physician Giovanni Filippo Ingrassia described the case of a patient with numerous red spots, large and small, distributed throughout the whole body, giving the appearance that the body was on fire. This was the first documented description of scarlet fever and was initially called &lsquo;rossalia&rsquo;[1]. By the 16th century, doctors had their first definitive description of scarlet fever. In the coming years, epidemics were recorded across North America and Europe<a href="#accordion">[1]</a>.

It is caused by Group A Streptococcus (GAS) bacteria. Thus, children with strep throat often develop scarlet fever. Burns and wounds infected with GAS can also result in the disease.&nbsp;&nbsp; 
&nbsp;

GAS causes more than 500,000 annual deaths worldwide<a href="#accordion">[3]</a>. GAS infections lead to mild diseases, such as pharyngitis, scarlet fever, tonsillitis, and cellulitis. 10% of people with GAS pharyngitis develop scarlet fever<a href="#accordion">[2]</a>.

Although the incidence of the disease considerably declined during the 20th century, researchers have recently reported an unexpected surge in Asia and Europe<a href="#accordion">[4]</a>. As per the World Health Organization (WHO), the incidence of invasive group A streptococcus (iGAS) infection and scarlet fever has been reported across several countries<a href="#accordion">[3]</a>. In the United Kingdom, scarlet fever outbreaks have been occurring in nurseries and schools. The country reported more than 4,000 cases of scarlet fever during the 2022/23 season<a href="#accordion">[3]</a>. France, Sweden, Ireland, and the Netherlands have also been observing a similar increase in cases. 
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There are no specific subtypes of scarlet fever. 
&nbsp;

Signs and Symptoms

Scarlet fever has an incubation period of 1-4 days. The disease typically has an abrupt onset and begins with a fever and sore throat. A rash develops 1-2 days after the onset of the first symptoms.

Scarlet fever has a characteristic rash that first appears on the neck, armpits, and groin, before spreading all over the body. The rash begins as small, red, flat blotches that evolve into tiny bumps with a sandpaper texture. Thus, it is also called a sandpaper rash. The cheeks may appear flushed because of the rash. However, the area around the mouth may be pale. Moreover, the elbow, armpit, and groin creases appear a brighter red (Pastia&rsquo;s lines) than the rest of the rash.

The rash typically fades in about 7 days. As it fades, skin peeling occurs around the toes, fingertips, and groin area. This can go on for weeks. 
&nbsp;

The common signs and symptoms of scarlet fever are:

<ul>
	<li>Fever (101&deg;F or higher) with or without chills</li>
	<li>Sore throat</li>
	<li>Pain when swallowing (dysphagia)</li>
	<li>Headache</li>
	<li>Body aches</li>
	<li>Nausea or vomiting</li>
	<li>Red and swollen tonsils</li>
	<li>Swollen lymph nodes in the neck</li>
	<li>Strawberry tongue (tongue is red, swollen, and bumpy with a whitish coating) 
	&nbsp;</li>
</ul>

Note: If you or your child do not feel better in a week or become unwell within weeks after recovering, contact a healthcare professional immediately. 
&nbsp;

The following signs and symptoms in children and teens warrant an emergency evaluation.

<ul>
	<li>Trouble breathing</li>
	<li>Shortness of breath</li>
	<li>Chest pain</li>
	<li>Inability to swallow</li>
	<li>Drooling (In children aged 3 years or older)</li>
	<li>Lethargy</li>
	<li>Noisy breathing</li>
	<li>Dizziness on standing or sitting</li>
	<li>Severe vomiting or diarrhea</li>
	<li><a href="https://merisehat.pk/disease/dehydration">Dehydration</a> 
	&nbsp;</li>
</ul>

Causes

Scarlet fever results from an infection with Group A Streptococcus, a bacteria that is also responsible for causing strep throat. These bacteria release a toxin into the bloodstream that produces the characteristic rash and strawberry tongue.

&nbsp;

The GAS bacteria are present in the nose and throat. When infected people cough, sneeze, or talk, respiratory droplets containing the bacteria are created. Inhalation or direct contact with these droplets can then lead to an infection. Sharing utensils or cups with an infected person can also spread the disease. Moreover, direct contact with infected sores of GAs skin infections is also a mode of transmission. 
&nbsp;

While there are no specific screening tests for scarlet fever, doctors typically base their suspicion on the findings of a physical exam. If they suspect scarlet fever, they may order a rapid strep test. 
&nbsp;

Diagnosis

The diagnosis of scarlet fever is mostly clinical and based on the person&rsquo;s history and physical examination. Doctors often use the CENTOR criteria to determine the possibility of strep throat in cases associated with pharyngitis<a href="#accordion">[5]</a>. The components of the CENTOR criteria are the absence of a cough, tonsillar exudates, cervical nodes, temperature, and age (less than 15 years). Patients with low scores may undergo additional testing while high scores may begin empiric treatment. However, the American Academy of Pediatrics does not recommend empiric treatment even in patients with high scores as there is a fear of antibiotic overuse. 
&nbsp;

The following two diagnostic tests can help confirm the infection:

<ul>
	<li>Rapid Antigen Test - If the test is negative, but the doctor still suspects scarlet fever, they may order a throat culture.</li>
	<li>Throat Culture - This is the gold standard for diagnosing scarlet fever. 
	&nbsp;</li>
</ul>

Treatment

The treatment for scarlet fever is similar to that of strep throat. Antibiotics, penicillin, or amoxicillin, are the first-line treatment. People allergic to penicillin can be prescribed first-generation cephalosporins. The antibiotics must be taken as per the doctor&rsquo;s instructions and not stopped in the middle.

Over-the-counter acetaminophen or ibuprofen can be used to treat fever and sore throat. Other treatment strategies include: 
&nbsp;

<ul>
	<li>Gargling with warm saline</li>
	<li>Drinking plenty of fluids</li>
	<li>Using a humidifier in the room</li>
	<li>Consuming soft foods while the throat is sore 
	&nbsp;</li>
</ul>

Children can return to school once they no longer have a fever and have been on antibiotics for at least 12 hours. 
&nbsp;

Note: Aspirin should not be prescribed to children or teens as it can cause life-threatening Reye&#39;s syndrome. 
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If left untreated or antibiotics are not taken properly, scarlet fever can result in the following complications: 
&nbsp;

<ul>
	<li>Skin, ear, and sinus infections</li>
	<li>Tonsillar abscess</li>
	<li>Rheumatic fever</li>
	<li><a href="https://merisehat.pk/disease/pneumonia">Pneumonia</a></li>
	<li>Septic arthritis</li>
	<li><a href="https://merisehat.pk/disease/bacterial-meningitis">Meningitis</a></li>
	<li>Bacteraemia 
	&nbsp;</li>
</ul>

In rare cases, scarlet fever can lead to a pediatric autoimmune neuropsychiatric disorder (PANDAS) associated with group A streptococci . The rare condition is characterized by a worsening of neuropsychiatric conditions, such as tic disorders. 
&nbsp;

The following factors increase the risk of scarlet fever: 
&nbsp;

<ul>
	<li>Age - Children aged 5 to 15 years are most at risk.</li>
	<li>Overcrowding&nbsp; - Crowding in child-care centers, schools, and military training facilities increase the risk of disease spreading.</li>
	<li>Strep throat infection.</li>
	<li>Close contact with an infected person. 
	&nbsp;</li>
</ul>

The following measures can help prevent scarlet fever: 
&nbsp;

<ul>
	<li>Practicing good hygiene</li>
	<li>Avoiding contact with people suspected of having scarlet fever</li>
	<li>Not sharing utensils or cups with others</li>
	<li>Covering mouth and nose when sneezing or coughing 
	&nbsp;</li>
</ul>

Key Points

<ul>
	<li>Scarlet fever is a contagious bacterial infection characterized by pharyngitis, fever, and a distinctive bright red rash.</li>
	<li>Children aged 5 to 15 years are most at risk of developing scarlet fever.</li>
	<li>Scarlet fever results from an infection with Group A Streptococcus (GAS), a bacteria that is also responsible for causing strep throat. These bacteria release a toxin into the bloodstream that produces the characteristic rash and strawberry tongue.</li>
	<li>Burns and wounds infected with GAS can also result in the disease.&nbsp;&nbsp;</li>
	<li>The disease typically has an abrupt onset and begins with a fever and sore throat. A rash develops 1-2 days after the onset of the first symptoms.</li>
	<li>The rash begins as small, red, flat blotches that evolve into tiny bumps with a sandpaper texture. Thus, it is also called a sandpaper rash.</li>
	<li>The diagnosis of scarlet fever is mostly clinical and based on the person&rsquo;s history and physical examination.</li>
	<li>A throat swab culture is the gold standard for diagnosing scarlet fever.</li>
	<li>Antibiotics, penicillin, or amoxicillin, are the first-line treatment.</li>
	<li>Children can return to school once they no longer have a fever and have been on antibiotics for at least 12 hours.</li>
	<li>If left untreated, scarlet fever can progress to complications, such as ear and sinus infections, pneumonia, rheumatic fever, and septic arthritis. 
	&nbsp;</li>
</ul>

[1] Scarlet fever: A deadly history and how it prevails. American Society for Microbiology.

[2] Scarlet Fever. Medscape.

[3] Increased incidence of scarlet fever and invasive group A streptococcus infection - multi-country. World Health Organization.

[4] Hurst JR, Brouwer S, Walker MJ, McCormick JK. Streptococcal superantigens and the return of scarlet fever. PLoS Pathog. 2021;17(12):e1010097. Published 2021 Dec 30. doi:10.1371/journal.ppat.1010097.