MCMURRAY, Pa. – Two Peters Township High School students have scarlet fever, a treatable disease that was once the leading cause of death for children in the early 20th century.

Officials with the Peters Township School District alerted parents to two recent cases of scarlet fever at the high school that were confirmed by health officials on Tuesday, WPXI reports.

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“Scarlet Fever is caused by a bacteria called group A streptococcus, the same bacteria that causes strep throat,” the notice reads, according to CBS Pittsburgh.

The disease is transmitted by mouth or nasal fluids, typically from children who touch their face and other objects, like door handles or toys, that are used by others. The disease also spreads from coughing and sneezing.

“The rash is the most striking sign of scarlet fever. It usually appears first on the neck and face (often leaving a clear, unaffected area around the mouth). It looks like a bad sunburn with tiny bumps, and it may itch. It then spreads to the chest and back and finally to the rest of the body,” according to Wikipedia.

“In the body creases, especially around the underarms and elbows, the rash forms the classic red streaks known as Pastia’s lines. On very dark skin, the streaks may appear darker than the rest of the skin. Areas of rash usually turn white (or paler brown, with dark complexioned skin) when pressed on. By the sixth day of the infection, the rash usually fades, but the affected skin may begin to peel.”

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Other signs and symptoms include sore throat, fever, red tongue with red spots, paranoia, hallucinations, swollen glands near the neck, chills, body aches, nausea, vomiting, and loss of appetite. The disease often starts with a fever of over 100 degrees followed by the rash 12 to 72 hours later, according to the site.

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Scarlet fever develops in some people who have strep throat and is most common in children between the ages of 5 and 15. If left untreated, it can have a serious impact on heart, kidney and other organ functions, the Mayo Clinic website states.

“The best way to keep from getting infected is to wash your hands often and avoid sharing eating utensils, linens, towels or other personal items,” according to the Centers for Disease Control and Prevention. “It is especially important for anyone with a sore throat to wash his or her hands often. There is no vaccine to prevent strep throat or scarlet fever. Children with scarlet fever or strep throat should stay home from school or daycare for at least 24 hours after starting antibiotics.”

There are typically fewer than 20,000 cases of scarlet fever in the U.S. each year.

“In the 1800s there were serious epidemics of scarlet fever. The death rate from scarlet fever then was as high as 150/100,000,” Patient.info reports. “Complications, case mortality and incidence have fallen dramatically because of antibiotics, enhanced immunity and improved socio-economic conditions.”

The site notes, however, that cases of scarlet fever have doubled in England his year in comparison to the number of cases over the last decade.