Between mid-September and the week ending March 18, more than 15,370 cases of the age-old killer were reported to Public Health England.
"Greater awareness and improved reporting practices may have contributed to this increase," said Nick Phin, deputy director at Public Health England.
Identified by a bright red rash that looks and feels like sandpaper, scarlet fever is a highly contagious disease caused by the same bacteria behind strep throat, group A Streptococcus pyogenes.
Public Health England is advising parents to be on the lookout for these symptoms, as if caught early, the illness is mild and can be treated with antibiotics. Early treatment can also reduce the chances of complications, such a pneumonia, and prevent the spread of infection.
"We are monitoring the situation closely and remind parents to be aware of the symptoms of scarlet fever and to contact their (family physician) for assessment if they think their child might have it," Phin said in a statement.
"It is a very contagious disease and much more common in children under 10 than teenagers or adults," said Professor Helen Stokes-Lampard, Chair of the Royal College of General Practitioners in the UK. "Scarlet fever used to be a lot more common than it is now, but GPs are noticing more cases than in previous years at the moment."
In recent years, England has seen a surge in cases, with cases tripling in 2014 from the seasonal average of 4,700 in 2013 to 15,637 in 2014, a recent study
Infections continued to rise to nearly 20,000 in 2016, a 50-year high for the United Kingdom, according to the analysis.
The health agency is also pushing family physicians, pediatricians and other health practitioners to be aware of the infection when assessing patients.
"Guidance on management of outbreaks in schools and nurseries has just been updated, and research continues to further investigate the rise," Theresa Lamagni, a senior epidemiologist at Public Health England, told CNN in a previous report
. "We encourage parents to be aware of the symptoms of scarlet fever and to contact their (general practitioner) if they think their child might have it."
Identifying scarlet fever
Although anyone who gets strep throat can get scarlet fever, also known as scarlatina, the disease typically strikes children under the age of 10. Frequently spread by droplets via coughing and sneezing, group A Strep can also hide on doorknobs, plates and utensils for hours.
The red rash that gives scarlet fever its name typically starts on the neck and face and spreads to the chest, the back and other parts of the body. At first, the rash will look like a bad sunburn, but then it will begin to raise and become bumpy. If pressed, the red skin will turn white; it can also be itchy. Once the rash subsides, the skin will often peel, especially on the groin, fingertips and toes.
A very sore, red throat that makes it difficult to swallow, along with a fever of 101 or higher, is a key sign of scarlet fever, along with swollen neck glands, headaches and body chills, nausea and vomiting.
An early symptom can be a "strawberry" tongue -- one that looks more red and bumpy than usual -- along with a whitish coating on inside of the throat. Other telltale signs include be a flushed face (except for a white streak around the mouth) and red streaks in the creases of the skin, with the armpits, knees and elbows showing a deeper hue.
Treatment for scarlet fever is a course of antibiotics, which must be completed to be rid of the bacteria and avoid a relapse. If the regimen is followed appropriately, the disease is usually gone within a couple of weeks. Left untreated, it can lead to serious illness or even death.
Complications of scarlet fever can include Bright's disease, a form of kidney damage, and rheumatic fever, an autoimmune disease that affects the heart, joins, skin and brain. If rheumatic fever affects the heart, it can cause long-term damage. That's one of the reasons scarlet fever was a leading cause of heart disease for adults before penicillin was discovered.