Parents of youngsters at two Falkirk schools have been warned to look out for the signs of scarlet fever.
It follows a possible outbreak linked to an outdoor centre in Perthshire.
Pupils at Easter Carmuirs and Carmuirs Primary recently visited the Dalguise activity centre which is at the centre of the investigation.
Scarlet fever is a highly infectious streptococcal infection which is on the rise across the country.
Parents have been informed of the signs and symptoms to watch out for, which include a pink-red rash, high temperature, sore throat, flushed face and a red, swollen tongue.
GPs throughout Forth Valley have also been told of the recent reported cases currently being investigated by Health Protection Scotland.
Dr Henry Prempeh, NHS Forth Valley’s consultant in public health medicine, said: “Scarlet fever can easily be treated with antibiotic tablets and once a child has completed the first 24 hours of their course, they should be able to resume their normal activities.
“There has been a seasonal increase in the number of cases of streptococcal infections, like scarlet fever, in Scotland. This is part of a general increase in these cases seen normally at this time of year and which is also being seen in the rest of the UK.”
He urged anyone showing potential symptoms to contact their GP or call the NHS inform helpline.
Health experts across the UK have noted a “remarkable increase” in scarlet fever incidence recently.
Analysis has shown larger scale outbreaks usually occur in four year cycles with the last peak year in 2008/09. England reported its largest weekly number of cases since records began in 1982.
Anyone attending Dalguise centre since March 28 this year and experienced symptoms should contact their GP.