Diagnosing scarlet fever
NHS Choices Medical Reference
Your GP can usually diagnose scarlet fever by looking at the characteristic rash and other symptoms.
To confirm the diagnosis, a sample of saliva is taken from the back of the throat (throat swab) and tested in a laboratory. This reveals which bacteria have caused the infection. A blood test is sometimes required.
Scarlet fever is a notifiable disease. This means that doctors must report any cases to the local health protection unit so they can monitor the spread of disease.
Blood test: A sample of blood is taken from a vein, using a needle, so it can be examined in a laboratory.
Bacteria: Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and others are good for you.
Fever: A fever or high temperature is when someone's body temperature goes above the normal 37°C (98.6°F).