Once a Victorian disease, scarlet fever has now reached a 50-year-high, as reports have rocketed in March.

According to Public Health England, around 6,157 new cases have sprung up since September.

With April being named by researchers as the peak time for the strain to spread in primary schools, parents are being urged to keep a look out for signs should their child fall ill.

What is scarlet fever?

Scarlet fever is a bacterial illness that mainly affects children, according to the NHS.

The illness is caused by Streptococcus pyogenes bacteria which are found on the skin and in the throat.

How contagious is it?

Scarlet fever is highly contagious. It can be caught by breathing in bacteria in droplets from an infected person's coughs and sneezes.

It can also be caught by touching the skin of the person with a skin infection, such as impetigo, or sharing contaminated towels, baths, clothes and bed linen.

There is also the possibility of it spreading from carriers – people who have the bacteria in their throat or on their skin but don't have any symptoms.

What are the symptoms?

Scarlet fever usually follows a sore throat or a skin infection.

Initial symptoms usually include a sore throat, headache and a high temperature (38.3C/101F or above), flushed cheeks and a swollen tongue.

A day or two later the characteristic pinkish rash appears.

It usually occurs on the chest and stomach before spreading to other areas of the body, such as the ears and neck.

The symptoms usually develop two to five days after infection, although the incubation period (the period between exposure to the infection and symptoms appearing) can be as short as one day or as long as a week.

The rash feels like sandpaper to touch and it may be itchy.

On darker skin the rash may be more difficult to see although its rough texture should be apparent.

I think my child has scarlet fever, what should I do?

Scarlet fever usually clears up after about a week, but if you think you or your child may have it, see your GP for a proper diagnosis and appropriate treatment.

Your GP should be able to diagnose scarlet fever by examining the distinctive rash and asking about other symptoms.

They may also decide to take a sample of saliva from the back of the throat so it can be tested in a laboratory to confirm the diagnosis.