Scarlet Fever: Signs, Symptoms, and Treatment

Thanks to the arrival of antibiotics, in the 20th century, the infection has been all but nonexistent in most places for decades, other than occasional upticks in cases in Great Britain and parts of Asia, including Vietnam, South Korea, Hong Kong, and mainland China. (1)

The exact cause of this slight increase is unknown, but global travel, overcrowding (which leads to more person-to-person contact in day care centers, schools, and cities), plus better reporting are possible factors.

Another intriguing explanation for the increase in cases is pollution. Research published in the International Journal of Environmental Research and Public Health found that short-term exposure to certain respiratory irritants raised the risk of scarlet fever. (2)

Also known as scarlatina, scarlet fever gets its name from its characteristic symptom — a scarlet red rash that feels rough to the touch and spreads over large areas of the body. Most commonly diagnosed in children ages 5 to 15, it is usually accompanied by other symptoms, which may include: (3)

• Fever above 101 degrees F
• Very red, sore throat; swollen tonsils
• Flushed cheeks
• Distinctive red lines in the creases of elbows, armpits, knees, and  groin
• Swollen and tender neck glands
• Headache or body aches
• Nausea, vomiting, or abdominal pain
  
• “Strawberry tongue,” a swollen tongue covered in enlarged, reddened taste buds that look like the bumpy seeds on an angry strawberry

Once antibiotics were discovered in the early 20th century, scarlet fever went from being a fearsome potential killer to “something easily treated by any pediatrician,” says Felice C. Adler-Shohet, MD, a pediatric infectious disease expert at CHOC Children’s Hospital in Orange, California. Treated promptly, it’s a mild illness that “shouldn’t be thought of as any more dangerous than having strep throat,” says Dr. Adler-Shohet.

Diagnosis is made by testing the throat for the presence of the bacteria, which can be done with any of several types of tests performed in the doctor’s office. One test, a rapid strep screen, can diagnose strep throat during an office visit. If the throat swab test confirms that Group A strep is causing the illness, the doctor will prescribe a 10 to 14 day course of antibiotics (penicillin or amoxicillin in most cases, or clindamycin or erythromycin for patients allergic to penicillin). (3)

If not treated promptly, scarlet fever can lead to complications such as:

• Ear and skin infections
• Pneumonia
• Kidney disease
• Rheumatic fever (3)

“Rheumatic fever is one of the most serious complications we worry about, because patients can be left with permanent heart damage,” says Adler-Shohet. Fortunately, it’s exceedingly rare, with just 0.04 to 0.06 cases per 1,000 cases in the continental United States. (Hawaii has a slightly higher incidence, as many as 0.1 cases per 1,000 cases per year, and, mysteriously, there is an even higher incidence among Hawaiian residents of Samoan or Hawaiian descent.) Unlike scarlet fever, rheumatic fever is not contagious because it’s an immune response and not an infection. (4)

Scarlet fever only develops in people who are susceptible to the toxins produced by Group A streptococcus. Infants tend to be at low risk, thanks to antibodies from their mother still circulating in their bloodstream. And while there is no vaccine, most people by age 10 naturally develop an immunity to the bacteria, which are spread by tiny airborne droplets released when an infected person coughs, sneezes or even just exhales. (5) Flu-like symptoms develop within a week of exposure to the bacteria, during which time it is easy to unwittingly spread the infection.

Prevention, therefore, is key to minimizing the risk to yourself and others. Some useful strategies are:

• Wash your hands often, with soap and water, for at least 20 seconds, or use a hand sanitizer containing at least 60 percent alcohol.
• Avoid sharing toys, bedding, towels and other personal items, especially unwashed eating utensils and dishware.
• Keep anyone with strep throat or scarlet fever home for at least 24 hours after starting antibiotics.
• Cover your mouth and nose when coughing or sneezing.
• Throw out used tissues immediately.